Thursday, October 1, 2015

The "I told you so" post

http://www.theguardian.com/environment/2015/sep/22/the-rise-diesel-in-europe-impact-on-health-pollution

Following VW scandal, new tests uncover that Mercedes is even worse, BMW does the same...and peugeot, toyota...well ALL OF THEM.

Why? Well because like I've been saying for years, diesel is a lot worse than gasoline...is engines and obviously pollution.

Of course no one listened to me because the manufacturers say it is good...than I must be true.

Time now for the revenge post: I TOLD YOU! Years...decades ago.

The Diesel is now on count down...finally. Next step: false hybrids.

Wednesday, September 23, 2015

VW... you are stupid... ballsy but stupid... and also right.

http://www.bbc.com/news/business-34325005


Shocked by the VW scandal, I decided to post this article.

I can't believe how stupid they here, how ballsy they were and ultimately how right they are.

Politicians, in their infinite stupidity think that the world will be better if the clean cars (gasoline engined) are less, and dirty cars (diesel engined) are more and more controlled by regulations that ultimately will kill the engine power making you pull it harder or buy a bigger engine.... ending in more pollution anyway.

There is a why to this: tax! More tax means more money for them... of course the idea of taxing a car that pollutes like a gasoline engine car, is to plant more trees and green areas to compensate... but that money is deviated... lets just say else where.

There is the other matter... by taxing gasoline cars, people flee to diesel ones, and that constitutes a bigger problem as diesel emissions include a lot of carbon particles... this is worse then gas, so the politicians add regulations and taxes to try to baffle the resulting pollution... no trees from taxes still, just more money.

So the game is: Make it as bad as possible and then tax on it and make fortunes.

In order to do that, every car, upon certification to a specific market will have pass a set of tests including the emissions test.

So far so good. We knew that already. The problem is that VW also knows that and ultimately thinks "I don't really care for stupid policies, and if you are making money on us, than I'll fool you".

So now for the news:
Every car that is fitted with ESP will not allow you to properly test it on a rolling dyno. The 2 front wheels spinning while the 2 rear wheels are stopped will immediately trigger EPS into thinking you are trying to accelerate on a slippery surface and dose the engine and apply the brakes... So to solve this issue every manufacturer has input into it's car's software a "test mode" that disables ESP actions.
Now if you are a manufacturer and you want to fool the emissions test, this presents an opportunity, however, if you are going to do that you must really conceal the crafts, as you will be stealing money from governments (the biggest "mafiosos" of them all)  in every car you sell from that point on.

VW did just that! they concealed a way to make their cars pollute 40 to 50 time less if a certain type of parameter was met.

This is not the problem. The problem is that if you are going down this road than you have to make it "look like a bug" in the software.

VW on the other hand coded a set of checks that produce a result...and that can be tracked.

Not that if it was a bug you would be out of trouble... it just makes it easier to explain in court, and that means that, out of the total 18billion fine, you could negotiate your way down to say... half that value!?

In the other words: your VW diesel that claims to produce x co gr/km actually produces 40 or 50 times as much. No worries, it still has that big power from a very small package and that is what you pay for actually.

So this is a big scandal not because it pollutes more, not because they are stealing from the government (and in turn helping you do the same... so now you have that instant karma feeling) but because they where stupid enough to do that in the clumsiest possible way.

Practical results form this stunt?
1 - VW will be fined... hard
2 - VW is stealing from govenrments everytime they sell a diesel car
3 - if you own a VW you have been and are stealing form your government every year when you pay your tax.
4 - VW will have to call back the cars and remap... so be careful! I have no idea how they are going to meet CO emissions while retaining the same power and consumption.
5 - VW stock is history.... sell... yesterday.

HONDA: you killed the brilliant K20A from the type-r and screwed-it-up with a turbo... instead you should have gone for full BTCC race tune to 300bhp NA and fit a jumbo catalytic converter that could be removed and replaced with a test pipe the minute one exits the sales stand. That would be legal, that would be efficient, that would still pollute less than any VW... and we would have loved it.

Test Drive - 2004 Honda Civic 1.7cdti (EP3 chassis)

This a very (very) old post that has been cooking for over 2 years.

There is a reason for this. Firs I tested the car using the standard Michelin energy tires... having driven the Type-r version my immediate impression was: this thing is all over the place! that high roof must really pull the chassis beyond it's limits.
Then, my first recommendation was: change the tires. Go for some proper rubber engineered to grip instead of fuel saving, and then I recommended the Toyo T1-R's I also recommended to increase the 195,60,R15 to a much more sensible 205,55,R15 with reinforced sidewalls to prevent tire wall smash.

The transformation was obvious... having decent road holding from the tires, the chassis actually comes to live and presents all it's magnificent design. Sure it was a bit too high but the stiffness on the tires and the grip was enough to force the chassis into full dynamics (not sure however of it's behavior if you have a transition from good tarmac into a less holding surface).

This was good news but I was out of time and so I had to leave the test... unfinished.

This last 2 months however presented themselves with an opportunity to clock some 10.000Kms on the same car. It was time to to through every type of pavement, road, condition... and check the car properly.

What a surprise. Not a good or a bad surprise but rather a mix.
Chassis wise the car is brilliant... one of the best FWD chassis, period! Grippy and very composed, the lift-off over-steer is controlled with ease and allows for some spectacular drifts...not just for show! Once you've mastered the dynamics of the car, you can keep a very fast pace on any b road. Sure you will kill the front tires fast like any FWD car, but the experience will be involving and with slim to none under-steer.
Turn in is precise and very willingly (surprisingly instantaneous).

Torque-steer however is bad news. I can clearly understand why Honda, having opted for a lower quality, inferior and ultimately cheaper rear suspension design for the new versions of the civic, decided into an improved front suspension design as it was would render anything beyond 150bhp and 200nm/torque problematic. Especially with the worse rear design, the front end would really need to be a charm.

Allow the car to slide a bit further than 20 degrees and you'll feel that the torque for the front wheels will work against you while you steer back when the car starts recovering... unpleasant and eventually dangerous in extreme circumstances. How to sort this out in your own car? kill the rubber bushings and fit some good, hard, polyurethane ones...also buy a bump-steer kit from spoon...now that you are at it, fit a set of coilovers.
That is the single most weird thing about the car. And having a heavy (really heavy) diesel engine, this is more perceptible.

The Diesel engine... not bad for a 1.7 common rail with an old design. The Isuzu unit is robust and bullet proof, but is is very heavy and since it is a diesel, response is something unheard of. So that is the ONE THING that spoils the package. Had this been a RWD it would kill the chassis competence completely (much like the BMW 1 series).

Appart form that it will cruise at 120km/h at 5lts/km (no AC)... and will average 6.2lt/Km in the 10.000km I've tested with mixed city and highway , with AC (with some highway stretches going beyond the 200km/h apparent limit).

The weight of the engine is very perceptible on speed-bumps. The front of the car easily digs into the ground while coping to deal with the front end weight and still remain "decent" in comfort settings.

It is comfortable enough for long trips (over 700km in a row)...clearly not as comfortable as my V70 T5 volvo, but if you compare chassis efficiency and joy vs ride comfort, this will eclipse the volvo anyway... it will eclipse most cars actually.

So this is a good car. Pitty the engine is diesel, so a 1.8i would be better... a lot better... pitty it is so high, to the sports version is the one to go for... and of course, if you manage to source the type-r 2.0 than there is no looking back,

Comparing it with the recent chassis, the EP3 is the last great Civic to have. So unless you are 70 years old and only drive on motorways, ignore ANY civic beyond the Type-R EP3... and that includes the new "shemale" turbo type-r.


Wednesday, September 16, 2015

Test Drive - Mini 1.6d

Engine.... engine... this chassis asks for engineeee

The mini is a brilliant little car. It always had been and when BMW took over the new version project it managed to input all the good "drivers car" knowledge they've always had.

It is FWD (not particularly good) but truth be spoken it is a brilliant FWD.
The chassis is very composed and the rear is as live on lift-off as the front is eager to bite into corners... and being so small this means one thing: agility.

This car allows you a very high pace thought a B-road jumping from bend to bend without any sort of inertia issues. It feels a lot lighter than it actually is, but that is good.

Just like it's RWD brother the 1series BMW, this car ask... begs... for a proper engine. And unfortunately just like the BMW's I've tested, it was Diesel.

Don't get me wrong, the car is very lively during acceleration and great for motorway cruising... but when you really need response and rev range, the diesel engine doesn't allow you to properly enjoy the chassis.

My opinion?
Buy the cooper works... the old one... with the compressor. I know the turbo performs better and is less of a pain to keep healthy... but if you want to enjoy the chassis, you need response and the turbos... well the turbos will always have response issues. :)

Did the treatment pills work? Is the Auto industry back on the sanity ground?

As you probably know, my view on today's automotive industry is pretty dark.

I'm a purist and as such, Honda going hybrid and 2wd turbo is wrong, toyota going hybrid is wrong... every manufacturer going 2wd turbo is wrong... everything is wrong out there expect maybe for some enlightened souls that mostly work for lotus... and a couple other manufacturers.

The problem? First came the politicians with their stupid taxes, forcing smaller and smaller engines to be produced... then came their policemen with orders to "invoice" and the speed limit made us run highways at parking lot speeds...then came Al-Gore and his army of zombie tree-hugers that killed some of the most brilliant engines ever made...and finally came the economists and mediocre managers that turned the engineering passion into a blind pursue of profit with total disregard for design quality.

These last years, we saw Toyota kill the Supra, Mazda kill the RX7, Honda kill the NSX...and the S2000... and the Civic Type-r...and the integra Type-r, BMW killed the glorious NA in-line six of the M3, Saab... well no more Saab and I could continue with the kill list on to the trash produced list starting with all and any hybrid with a battery bigger than a standard car battery.

In truth, we have gone back years in engineering terms. I find my self worried, because I'm now buying cars from no later than 2006... and eventually as the years go by and I need to replace them, I might find my self out of options.

Well It seems from this last week that there might be a salvation in the industry after all.
Behind all that madness and stupidity that produces hybrid crap and cars that are as dull as the advertising stating it pollutes less than your farts, some engineers might actually have survived.

So out of those manufacturers that where extremely hill, Honda make the top of the list. With extra needed care as the "return" they attempted was a copy of the recipe from Renault and VW... stating that such a level of desperation could mean "terminal case".... but I guess that some miracle drug treatment worked and a couple of engineers actually survived. They went to the surviving BIKE department, grabbed a proper NA stratospheric revving engine and put it into a car, then the materials and minimalist design, then the disk brakes and controls... and the result, is a brilliant drivers car.

The Honda 2&4 project is an extreme vision of the same genesis I had with my S2000rr concept...and I love it.



Finally, after years stating that Honda was dead to me, I can say that there is a sign of recovery. There might be resurrection after all.

The other manufacturer is a less complicated case. I mean they did got the Turbo on FWD disease (they got that big) but at least they know what is the proper usage for a cars battery.

FORD was BIG. They has the RS Cosworth... they had 2, the Sierra and the Escort... and for the enthusiast that doesn't want to go sideways, they had the FWD, non turbo XR3i... and they had the brilliant fiestas. Then some designer smoked really bad weed and they entered the "new edge design"! Horrible cars to say the least, but at least the chassis design team where working as good as ever and the ugly cars performed brilliantly... and enginewise... well they turned to Yamaha for those... I mean no argues there.

But then the Escort was gone and the Focus needed to show that it was a true successor (not an easy task).
We waited and Ford unveiled the Focus ST... is this the new Cosworth? let me see... no! it FWD YUCK!
Then came the news that the REAL beast was underway and that the RS would have the T5 volvo engine... this was promissing... and when it came out it was... FWD!?!?!? TURBO?!?!?! Why oh why would FORD put a beast of an 5 cylinder TURBO engine on a FWD car??? And as expected the differential Quaife put there and try to solve the impossible,  generated very violent torque steer. Not just bad... stupid!

And Fords performance car became the much better handling and less power through the front wheels Fiesta!

Then FORD knew about the rehabilitation clinic HONDA had just entered and tried some of the same medicine... and voila!
The all new Ford FOCUS RS 2016 is a 2.3 turbo, BUT it is, as every turbo should, AWD!
Not just that, they beefed it up with active diffs and the computer that controls them has a "drift" mode :) and just to put the cherry on top of the cake, do you know who they used to tune the "Drift mode"?
Ken Block! I mean the guy doesn't drive competitively in rally, but give him a junkyard, unlimited set of tires and replacement cars and time, and he will manage to drive sideways the entire time, even indoors... between pillars... and container towers.... and inside airplanes...under a jumping bike...while in the air...and talking to James May!

Ken Block may not be king of rally but he sure is king of gymkhana ... and having set the RS drift mode, fun is assured :)


Well done Ford... and welcome back...now please continue to take the medication before you create a 500bhp 2.0 triturbo FWD Ka, ok? ok.

Sunday, July 5, 2015

Test Drive - Audi A4 Avant 2.0TDI 170bhp B8 chassis


I'm just reviewing the engine on this unit as the remaining features are exactly like the 140bhp review.

The engine: Not so bad. Unlike the dull, lifeless 140 common rail, this feels a lot beefier.
It is still round enough and able to sustain power for a good usable 2500rpm.
It has a duality of character to it... don't push beyond 2500rpm and it will consume very little fuel to maintain speed... step on it, on the other hand and you will start wondering if this is diesel or gasoline... not because of the power but rather the consumption.
Not brilliant (it's a diesel... not much to expect from it) but it is very decent.

Conclusions: 
It is fair and for motorway cursing it is economic...if in doubt between the 140 or the 170... go for the 170... no question about it...or...buy the 2,0TSFI, revo-it and you are better off.. but if you really are looking for a chassis that corners with you, instead of against you...(and don't mind the ugly looks and bad plastics...did I say ugly?) buy the megane and save a tone of money.

Test Drive - Audi A4 Avant 2.0TDI 140bhp B8 chassis


With over 140.000 km on the clock, I must say that it's a brilliantly built machine. No noises, no major issues apart from the standard maintenance program... much like the gas version and this is no surprise because though it vibrates more than the gas unit, the engine is actually well balanced.

And so the test begins.

The engine: A bad surprise... this was the engine that replaced the PD130 and PD150... this is 16valves (don't really understand why 16v on an oil burner) against the 8v.. it is claimet to have 142 bhp... but it actually feels less!
I must say, in it's justice that if is as round as the PD150 was, and not a brute hulk like the PD130... but the common rail, 16valves crap really killed the engine.
It feel s as if the turbo is not working properly. Low down torque, however is very good... so, at traffic, all you need to do is lift off you clutch a bit and it will get you going.
One good surprise was fuel economy... if you don't push-it beyond 2500rpm it will run with excellent mileage.

The Gearbox: I must say this gearbox is very good.
Perfectly matched to the engine, perfect command weight, the engagement takes the propper force to happen and it feeds back exactly the info you need without letting you feel you are touching metal. Very refined touche but clearly the win is the engine match...
In this car it is a must as if you try to heel-toe, it will miss-understand you and emergency mode the engine... stupid i know.. but seem to plague the ESP units on all the VAGs.
So this gear box is a joy.

The Chassis:  This is almost copy paste on the A4 2.0 TSFI review....it's an Audi... it is very composed and with good grip levels (particularly after fitting bigger rims and tires). The grips is good enough to make you think it's lighter that it actually is, but it is not as involving as...say... the megane3 break chassis.
The one problem with this car... as any other AUDI is the let-go... UNDER-steer. It's like this by design as the every day banker that buys them really doesn't know how to drive and in an extreme situation, will get scared and break... so all AUDI's except the R8 are tuned to under-steer on the limit.
This however is the exact opposite behavior you really want on a curve as what you need is the chassis to help resolve the curve by biting in with the front axle and letting go the rear to roll the car into the corner.
Again, much like the twin 2.0TSFI test:
This could obviously be solved with a handbreak strike but no... noooo! the hand break on this is electrical.... how stupid of you audi.. this was the one thing that could solve the chassis stupid fine-tuning and you manage to eliminate it!.

Conclusions: 
It is fair and for motorway cursing it is economic...
Buy the 2,0TSFI, revo-it and you are better off.. but if you really are looking for a chassis that corners with you, instead of against you...(and don't mind the ugly looks and bad plastics) buy the megane and save a tone of money.


UPDATE:
This car was now fitted with a set of 18" rims running Bridgestone RE050a tires.
What a transformation. This simple setup made the car's turn into the corners a LOT sharper. The grip levels increased and the on-the limits under-steer that annoys me so is now let evident and more composed on the let-go and recovery from it.
A MUST. This chassis was clearly designed for big rims, low profile, wide tires and with high grip level.

Test Drive - Audi A4 Avant 2.0TSFI s-tronic B8 chassis (on a REVO Stage 1 remap)

I've now covered around 5000km on the A4 Avant 2.0TSFI s-tronic.
With over 130.000 km on the clock, I must say that it's a brilliantly built machine. No noises, no major issues apart from the standard maintenance program.

This unit is a very curious one... you see, the major problem with the world is the politicians... well if you think of it, it is actually people that elect them, but still, they create stupid laws to steal money from you. One of those laws exists in some countries where you pay a tax for the BHP you car has! Some other countries make you pay for the displacement your engine has... and some a bit more evolved make you pay for the impact on the environment... but then do not use the money from the tax to counter that impact... utterly ridiculous.
Spain in one on those countries that think that BHP is bad for the environment... so if you have an good old oil-burner 2.0 that paints your city black with smoke but only has 60bhp, you are a good civilized citizen!
Still the fact that politicians are stupid doesn't mean that the people at AUDI are...thank goodness.
So they build the 2.0TSFI engine for 210bhp...as they do for every other country... and then when legalizing in Spain, they just detune the ECU to 180BHP and happy day you can buy your car cheaper.

So why oh why was this soo cool? Well the owner of the car felt the drive-train was better than the engine, and as such he chose to buy a REVO stage1 remap.
Now this remap gives the standard 210bhp an healthy 40bhp plus... but since the REVO code doesn't recognize the Spanish law, it thinks the ECU is actually the standard 210Bhp ECU on a different version... and it is absolutely right...and so re writes everything, unlocking the 40Bhp promissed + the constrained 30Bhp... what a blast. A 2.0 4 pot that unleashes 70bhp from a stage one, off the shelve remap.

And so the test begins.

The engine: No surprises here... it is quick! it revs happy, the factory turbo is more that up to the job and the new found power makes the standard wheels and tires scream at every standing still pull... new rims and rubber underway, no worries.
It was a perfectly decent engine... sure not an efficiency benchmark but a very decent and  livable engine. Now it is much more responsive, the surge of power is more round and sustained showing the FWD limitations essentially on the standing still pulls... don't get me wrong.. .it is FWD and turbo, so if you floor-it mid corner you will have under-steer (or ESP kick-in)...but the new found linear response of the engine, allows you to pull gently out of the corner IF you dose the throttle.

The Gearbox: wow ... I hate automatic gearboxes... I find he torque-converter something as stupid as hybrid cars are... I mean it's an element that enables you to convert torque from the engine to the weeels by passing oil though a closed doughnut with some fan-blades.... clever as it is, the fact is that the fluid is not a solid mechanical link as as such drains torque.
The S-tronic on the other hand is the evolution of the well known DSG. If fact you have 2 different sets of gears, the pair ones and the impair ones... each set on it's own shaft. The S-tronic has them both in sync and ready to engage as you decide to shift and then operates 2 different sets of, multi-disk clutch... one engages the pair gears and one for the impair shaft.
The result? a truly quick, no fuss, mechanical link shift. There is more... the S-tronic has 7 forward gears for you to use.
The manual control (in sports mode) is quick and obviously computer monitored so you don't over-rev nor under-rev the engine. Coupled with this engine it makes the car seem a lot lighter that it actually is.
So I really don't like automatic transmissions, but I do consider this do be a piece of engineering.... especially after opening one and seeing how it is made.

The Chassis: It's an Audi... it is very composed and with good grip levels (particularly after fitting bigger rims and tires). The grips is good enough to make you think it's lighter that it actually is, but it is not as involving as...say... the megane3 break chassis.
The one problem with this car... as any other AUDI is the let-go... UNDER-steer. It's like this by design as the every day banker that buys them really doesn't know how to drive and in an extreme situation, will get scared and break... so all AUDI's except the R8 are tuned to under-steer on the limit.
This however is the exact opposite behavior you really want on a curve as what you need is the chassis to help resolve the curve by biting in with the front axle and letting go the rear to roll the car into the corner.
This could obviously be solved with a handbreak strike but no... noooo! the hand break on this is electrical.... how stupid of you audi.. this was the one thing that could solve the chassis stupid fine-tuning and you manage to eliminate it!.

Conclusions: 
It is good... it is built for the highway and if you revo-it it will be a lot nicer... but if you really are looking for a chassis that corners with you, instead of against you...(and don't mind the ugly looks and bad plastics) buy the megane and save a tone of money.... oh now wait.. no decent petrol meganes except for the RS. Better think about a Skoda RS then :)

TorqueVsFuelVsLPS

The relationship between torque and power is poorly understood by the majority of people.
I gather this as people usually say "I've got the 130bhp TDI" ... or the "I've got a 700nm turbo gasoline engine".

So lets start with the Fuel as this actually separates everything- Gas vs Diesel :
So; the way fuel burns is very important for you to understand the engine you have. 
Gas engines input air and gas (the so called mixture) into the cylinder, and then compress it all (normally at a 11 to 1 ratio) to a point when the mixture is ready to blow... a small spark triggers this.
The point here is that the mix is ready to blow while it is getting compression and this adds to the "explosive effect". The more RON (or octanes) the fuel has, the better it will resist compression and not detonate. When the fuel detonates prematurely you get the auto-detonation effect that can hurt the engine... it also produces a high pitch PING on the engine as ALL the mechanical parts involved into the compression are pressed against each other and actually squirt the oil between them dry.
So this mix is being compressed and ready to explode... and the higher it resists the more voilent the explosion when it happens... and that is why high compression and high octane fuels will produce more power, quicker and with much more heat.

HOWEVER... there is a limited amount of time an explosion can happen, this will vary with the violence but in the end, as the engine accelerates, the explosion will have less and less time to occur. 
So a Gas engine will have a variable "timing" advance on the spark... this basically means that, the faster the engine needs to spin, the faster the timing advance will be. 
The other part of this equation is the AFR... the Air-Fuel-Ratio will regulate the amount of air to the amount of Fuel in the mix.
So Mix 101 - a Perfect mix is called stoichiometric mix.  It is composed of 15 grams of air to 1 gram of fuel. This is called the perfect mix as it will take 4 to 5 milliseconds to burn. So a normal engine running at 6000 rpm, would have a full rotation in 10 milliseconds, meaning a full piston stroke at 5 milliseconds, in turn, meaning that the mix would explode fast enough. However due to the extreme heat generated by this type of burn and the simple fact that not every one runs pure race fuel, it is rarely used. 
Normal fuels produce a stoichiometric mix at 14.1:1 because of all the crap... sorry... "additives" in it... a pure octane fuel would run at 14.7:1 pushing it to the near ideal formula.
The mix in a normal gas engine ranges from 12-13.5:1 depending on the fuel and the ability of the ECU to decide. This is called a rich mixture and will generate MORE power... it will however take a bit more time to burn and do timing advance is needed.
The ECU will vary this, obviously, and the consequence is as much as 35degrees advance BTDC (before top dead center...or before the piston reaches the top of it's movement and stops before turning back).
There is also something in the timing equation called inertia... sometimes the engine doesn't advance as much as it would require because the excessive pressure while it compresses the exploding gas, could turn the engine to a backspin... The rotation of all the engine parts produce a positive spin inertia that helps countering this effect, but the less speed it has, the less inertia it has. That is why it is so dangerous to advance the ignition at low revs, especially and a high efficiency engine (or a cross plane crank one).

So... it should be clear by now that the explosion of the gas-air mix is violent and quick... but it happens once. That is one of the reasons for the gas engine to have low torque and high rpms.

Now the diesel engine ... or so called " the fuel of the devil" to a true motorhead:
The diesel engine works a lot like the gas engine... pistons, valves, motion... and that's about it! 
The Deisel engine does not input a MIX of air + diesel! It intakes JUST the air...no fuel. 
So as a consequence, the diesel engine can compress way beyond 11:1... it typically compresses around 18 to 20:1.... it's just air so it will not explode on it's own. 
The explosion comes from the injection of fuel direct into the piston head... creating a controlled, phased detonation that is kept while the fuel is being injected into the piston. 
That is why the diesel pistons have that half-donut like groove, with the cone like "spreader"... so that the injected fuel explosion is redirected and spread across the entire chamber. 

This means that while on a Gas engine the explosion is one, once and violent... on a diesel, the explosion keeps happening ALL THE WAY down the piston course, and since the diesel is basically just oil, the explosion is much less violent...and in consequence slow as hell. 

Facts time about the fuel type on your engine:
The Gas engine has a single, violent and fast explosion... making the engine generate less torque, but also making the engine able to generate a lot more RPM.
The Diesel engine has several slow, lower energy explosions all the way down the piston course...generating loads of torque but not being able to do that quickly enough to generate high RPMs.

The first conclusions?
If you are buying a diesel car, that you really do not care about the bhp, but rather the torque curve on your engine.

If you are buying a gas engine car, that the torque you want is the torque to handle the loads you are going to press the car against... it's weight and losses due to transmission. Because what you really want it that torque to be able to be translated into BHP by means of rpms... so yeah you want some torque... but not too much, as that will generate wheel spin...but you really want high rpm with high bhp at high rpm. 

If you are pulling a caravan, do not use the gas engine...it just doesn't have the torque without having to become MASSIVE in size.
If you are racing a car, do not use the diesel engine...it was not built for generating power on high rpms... and you don't race at 2000rpms!


Now for the second part... engine design, torque and the so very important LPS... and a touch of valve fluctuation.
Lots of people do not understand the redline on their engine, why it exists and why does the 2.0 version of the car rev 1000rpm more than the 2.2 version of the same engine on the same car.

Engines basically turn linear motion into rotative motion. They do so by connecting a linear working part (the piston) to rotating part (the crank shaft), with a rod. 
Having this clear let's go back to the physics class most weren't paying attention to: moment=f x rod
IF you try to open a door, grabbing the door 2cm from it's pivot point, and then do the exact same thing but using the handle (a good 80cm from the pivot point), you will notice that you have to effort a LOT less by moving the force away from the pivot point. 

Now apply this principle to the rotation of the engine assembly you see above: IF the point of the connecting rod on the crankshaft, moves away from the pivot point (the center of the crankshaft and flywheel), then the effort needed to turn it is far less. 
Since the rod pulls and pushes the piston, the bigger the distance, the bigger the rod and as a consequence the longer the travel the piston will turn.

So by now it should be clear that a piston that travels a longer run, will be able to produce a better moment, or a better rotation force... and that is torque? yup... it's the rotation force.

Now enters another part of the physics on an engine and that is the effects of acceleration and deceleration on materials... the so very important INERTIA. 
Inertia is a lady you all should learn to respect as it ultimately can kill you in many more ways that it will give you pleasure.
Now inertia says that, putting something in motion requires more energy than just maintaining that motion.... just the same as countering that motion requires a lot more energy than maintaining that motion. And the heavier the thing is... the worse. 
So picture you have a bank safe on a skateboard. Making the safe move will consume a lot of energy, but once it is moving it is easier to pull... then something gets in your way and you need to stop the safe from moving... now that is something to experience as you will have to press really hard agains the movement of the safe to stop it. 
You see, a piston, ultimately is metal, that ultimately is a bunch of molecules of several metals and carbon mixed together. Making metal move, will generate stress on the molecules as they are "glued" together.... so if the piston has an anchorage point (where the connecting rod links to it), the remaining parts of it will only be linked to that point by the molecular bond on the metal. 
If the piston moves up and down very fast, every time it stops and turns back, the majority of it's metal will try to continue the movement it already has and this generates stress. 
Generate too much stress and you will crack it... continue and you will disintegrate the piston:
So there is only so much a piston can handle in terms of pressure.

You also need to understand that the pressure of the piston against the cylinder walls, generate drag that will then generate heat! The faster the travel the more heat is generated... too much heat and:
... it melts!

So a pre-summary:
The more a piston travels, the more toque it generates.
The faster a piston travels, the more chance it has of melting.
The more it changes direction at speed, the more change it can crack.

The engine design part:
There are 3 types of design on the engine... 
The SQUARE engine -  when the diameter of the cylinder is equal to the length the piston runs inside the cylinder.
The OVER-SQUARE engine - when the diameter of the cylinder is bigger than the length the piston runs inside the cylinder.
The UNDER-SQUARE engine - when the diameter of the cylinder is smaller than the length the piston runs inside the cylinder.

Now comes in the LPS the Linear Piston Speed -> this is a means to measure the speed that the piston travels distance inside the cylinder. This keeps changing from 0 to well over 30meters/second back to 0 ans the piston accelerates and decelerates back. 
Since this varies too much, a MPS equation is set... MPS is the Mean Piston Speed. it is calculated as, MPS = 2 x stroke length(in meters) x rps(rotations per second.... or RPM/60).
An normal engine will run a maxmimum 22m/s MPS.
An high spec street engine will run 25m/s and be able to withstand 28m/s for seconds before starting to have structural damage at metal grain level.... A.K.A starting to micro-fissure.
An racing engine will run 28m/s to 29m/s and peak at over 32m/s (but will show fissures at the end of the race)
An very light racing engine will run 35m/s...but will have catastrophic failure within hours (if not minutes) 

Since an OverSquare engine makes it's volumetric capacity by having large bores on the cylinders, but very little distance to stroke, it's pistons run less distance per rpm... allowing you to pull the RPM limit further (assuming the fuel allows you to). 
On the other hand, an UnderSquare engine makes it's volumetric capacity by having a long stroke. This forces the piston to run longer distances in shorter time per rpm... so if you push-it... it will crack and/or melt the skirts.

So having ALL this into account, you have to choose one out of 2 things:
either you have a OverSquare engine that produces lots of RPMs while still within the safe 25m/s range...ooooor you have a UnderSquare engine that will produce better torque but will reach the 25m/s MPS limits at a lot lower rpms.

This is why the Honda F20C engine redlines at 9000rpm, and the Honda F22C engine (equal in everything except a longer stroke that gives him an extra 200 cc) will redline at 8000rpm.

Now is time for another pre-summary:
IF your engine redlines as 5000rpm, do not pull it beyond that mark for over 2 or 3 seconds... you will be generating micro-fissures in the pistons and over wear the pistons skirts... in time, those will become full blown cracks and will lead to catastrophic failure.

If you engine produces less torque and you want to increase it, the healthier way is by stroking the engine, BUT if you do so, then LOWER the RPM limit.

If you are boring the engine to have more displacement, then DO NOT increase the RPM limit... you can only do that if you reduce the stroke!

And the very important: if you lower the engine stroke to be able to have more RPM's, then you also need to reinforce the valve springs and eventually get lighter valves. The Valve fluctuation phenomenon will happen if they are forced to work at higher RPM's that they where engineered for... with will eventually lead to a piston touching the valve and kaboom... it can bend the valve or/and crask the piston. 

The HP vs TORQUE
A lot of people say that HP doesn't exist... but they are wrong. It does... what it is, is a byproduct of torque at engine speed. 

The formula is : HorsePower = (rpm x torque)/5252

So the HorsePower, being that the 5252 is constant can be said to be the torque at speed of the engine.
And this is where the idiots that like to say that "a torque wrench has more torque than a honda engine" will have to eat their lack of knowledge for lunch.
The way an engine produces torque is limited in the way it is designed and the fuel being used. 

A long stroke 1.9 diesel engine will produce torque as low as 1000rpm, peak at 1800rpm with 310nm not sustain it and slowly decrease and then die at 2500rpm..allowing to push to 3000rpm with some HP.  This means 2000 usable RPM. 
A long stroke 2.0 turbo gasoline engine may generate a decent toque figure at 2500rpm, peak at 3500 rpm sustain for 500rpm with 360nm, and decrease with decent figures till 5500rpm and then redline at 6000rpm. This means 3500 usable RPM
A shortstroke 2.0 non turbo engine will generate lower torque levels but a decent level at 3000rpm, then peak at 6000rpm with 202nm, sustain the torque till 8000rpm and decline to the 9000rpm redline. This means 6000RPM of usable engine.

There is also a catch here! The diesel engine produces 130 HP, the 2.0 turbo gas engine 265 hp and the 2.0 N.A. engine 240hp. 
However, the longer stroke on the turbo, gas engine, means that the MIX explosion time will not happen in a perfect manner... a lot of the explosion force gets pushed into the cylinder walls instead of directly into the piston, at the most "vulnerable" time in the gas expansion... and this gets worse as the piston goes down and the explosion is already past the peak. 
That long stroke does have a better effect on the sustained diesel engine explosion than it has on an one time explosion of the gas engine... and that is why the torque figures drop faster in a longer stroke engine than a short stroke one.

Is there a lesson to learn from? yup! torque should be matched to the weight the car needs to pull and the mechanical loss involved in pulling it (gearbox and traction system)... then the torque curve needs to be set in order to have the maximum possible engine for the longest possible time.. and since while racing, you lose time every time you shift, there is a considerable advantage to have more rpms...

And this is why the following video shows 2 cars of equal engine HP but different weight and torque figures... they both have 250BHP, the TURBO car has 9% plus weight to a 45% plus torque figure... but a very crucial 3000rpm LESS than the N.A.

So is the Honda better? Engine wise... yup!
chassis and usability is another thing... that brings even more variables into the mix. They are both front wheel drive cars, DURING a corner, the N.A. engine will generate less torque and this means that it will be able to step on the gas heavier and earlier without upsetting the traction as much as the excessively high torque figures the megane has would allow... this of course is without taking into consideration the torque biasing diff on the megane that would even this by cutting the engine power and actually sending more torque to the wheel with the better grip.
So purelly mechanically speaking the excessive torque would be a problem in the megane... out of the corner, the megane would pull with better acceleration on the same gear while the honda driver would have to be either pulling the same gear and using the 3000rpm on VTEC, or shifting down to keep it within VTEC range... so this would depend on the track... if the track would have climbs out of corners, thought, the megane would clearly be in it's kingdom (and this partially explains the ring time it has for marketing).

The Summary:
Torque is a way or expressing the engine capacity to pull weight. It can be generated in the form of sheer weight (like a truck that needs to have a diesel engine) or multiplication through gears, as the standard everyday diesel car has.
Given the right conditions, you want your engine to have more RPM and high power at high RPM than a high figure torque at low RPM... This becomes more evident at speed in a high gear, as an engine built for low end torque is out of it's element as the air being pushed in front of the car gets more difficult to cut through. That is when you need the torque that was really big in the beginning but is now long gone...and then you need to shift, because you are out of engine!

This is why the best tarmac motorsports cars use very high revving engines like F1 18000 rpm (some used to have 20000rpm, DTM 9000rpm (some with 12000rpm), BTCC 8500rpm and so on. the usability on those engines is much better that with more torque and less rpm.

Rally, with their heavy 4wd systems and very difficult terrains, on the other hand, are all limited to 6000rpm and a peak of 300bhp to 340bhp at 5000rpm. This is where you really need toque as the 4wd car passing a muddy up-hill will height twice as much... at least.



Saturday, January 4, 2014

The "Honda is back" title and the "She-male picture" effect.

Be careful... explicit language ahead!
When I was a teenager and the internet was sloooow as an 18-wheeler truck, being the brat I've always been, I experienced the wonderful world of internet porn in the soooo very sllllooooow picture loading anxiety way. One day, while waiting for a picture of  naked girl, I was taking my time to appreciate things (no other way as the link was sllloooooow), the girl (so I though) in the picture was covering her face with "her" hair, then the silicone breats came up.. and right when I was so very interested in the remaining part of the picture... well you know what happened just by the "she-male picture effect" in the article title. It was discussing (not because I have anything against she-males) because I was really expecting something else.

Why oh why would I share this traumatic teenager experience (particularly in a car blog)? Well it happened again.
I was browsing magazines today and this came to my hand:

I was immediately excited (just like a teenager waiting for a naked women porn picture). I'm an former Honda lover, but lately Honda managed to do nothing but crap. I mean there is not a single car out of Honda since they stopped the JDM Civic Type-R production.
Every other manufacturer is trying their absolute best to build better cars and Honda managed to go the opposite way.
This Magazine was GREAT NEWS! FINALLY, one of the best brands in the world decided to wake-up from the prolonged coma. NSX was back, rumor of the S2000 replacement and a new Civic Type-R. Groooovy.

Immediately I skipped all the junk pages into the article, searched for the specs and found a chart of the new vs the old Civic Type-r specs. That was wonderful... a chart.
First line: new type-r - 300bhp, old type-r 200bhp    (BRRRRIIILLLIANT!)
Second line : new type-r - 2000cc, old type-r 2000cc    (yeeeahhhhhhh finally some racing specs for the road.)
Third line: new type-r - i-Vtec , old type-r i-Vtec    (obviously... no need to mention this)
Than disaster on the Fourth line: new type-r - TURBO, old type-r N.A.   (WTF?!)
I immediately dropped the magazine to the floor and almost cried in pain... and there you go-> The She-male effect.

This is the second time Honda kills the Type-r!!!
Mk1 was brilliant.
Mk2 was the best ever.
Than, for some reason, while producing Mk3, they decided that the JDM version should be better and the European version should have a cheaper (and worse) suspension and more weight!!! Weird at least.
Now with the Mk4... it's turbo.. I mean -cheap engineering instead of refinement, N.A. response...purity.. naaa just another 2.0 turbo to go after the RCZ, Sirocco and MeganeRS cheap trend.

If at least they had made it 4WD I would understand it... but no! Still FF. I can even say with no reserves that this car has been made to shut Renault up with their "Megan RS Trophy is the fastest FF in The Ring". According to some people from the R&D at Honda, they've done-it... but just like I hated the Megane for not being a pure driving machine... I'll also hate this one. Yes it's a record breaker...yes it's a bullet in the ring (where it was destined to perform)...but forget the refinement and driving experience...no room for those here.
Type-r is now the meaning for: just another engineer's wet dream.

So... Apparently the Megane RS has it's kingdom threatened (no surprise as an engine that revs to 6000 and produces little over 260bhp from 2 liters and a turbo is not a marvel of engineering)... and of course, just like Renault has F1 heritage to help build brilliant chassis, so does Honda...and they also have Indy, and BTCC and so on ... a brilliant FF chassis would come up eventually.
So this new Honda revs 2k beyond the Renault's limits, with better linearity and power delivery... and produces more power... give it a good chassis and you have a winner just on the 2k extra revs in the corners and the almost 40bhp in the straights!

But do I like it? No. It's FF instead of FR, It's turbo without being 4WD... and it was conceived following the EasyWay instead of the Hard-Engineering-and-true-Efficiency-seeking way.
Deception... pure deception. Hope that they remember the original S2000 and NSX on their new versions... or things will really get weird from now on.

Friday, May 24, 2013

Buying a used S2000? Learn about the car first (Updated version)

This post comes as a repetitive request from some of my youtube followers.
A lot of people ask-me for advice while buying an S2000...and they should. You see, I've checked around 10 cars on sale before I brought mine. The reason is simple: A lot of them are involved into really big accidents. You see, the car is pure and almost perfect in it's behavior...it's very race oriented.

One of the reasons for that perfect behavior is 50/50 weight distribution...being front engined and rear drive, the engine is back in the engine bay (hence the front-mid-ship design), this will cause the front wheels to have little space in it's wheel bays, and as a result the car has a small steering angle.
Add a small steering angle, to a LSD (trosen type... means LSD only IF all the drive wheels are on the ground...and that is a VERY important feature/flaw) rear wheel drive that jumps from non Vtec to full Vtec at around 6000rpm (5900 precise), and handles like a race car.. and you have, either the recipe for disaster, or the car of your life.

The choice is made from the skill the driver has. I've never ever driven a car this honest and balanced this side of a lotus elise, I've also never de-recommended a car so much to inexperienced drivers...and by experienced I mean race-track experienced. That is why its so hard to find an S2000 that has never had a crash because not all S2000 owners are race-car driver material.

The checkup list is divided into exclusion points, so it helps you decide.

Having said that I'll start by the "DO NOT BUY" list:
Twisted Xframe:
The S2000, just like the Type-r Engines and the NSX car, was almost entirely hand built by the "takumi" at Honda. These where highly skilled builders with over 10 years experience on building fine-engineering parts or cars at Honda factories. They where the best of the best at Honda.
One of the most important parts of the S2000 is the X-frame chassis. It's built so that the car has the same rigidity topless as a normal car would have with top.
To put things into perspective, the S2000 is hand built by the "Takumi", except for the XFrame that was put together in a special HOT template machine by robots. It was done that way because it was extremely difficult to weld-it together without letting it warp and twist. When twisted it would be extremely difficult to put it up to spec again and even so, it would not have the same torsional resistance without heat-treatment...to conclude: it was done that way due to technical difficulty in doing it by hand and removing twists from the welding process. So you can imagine the huge problem it is, it the car you are buying had a major crash... yup if the Xframe twisted, the car is gone! you will never ever be able to traction it to place... the X Frame is either immaculate or need replacement. No possible fix here.
It's easy to know the most important parts when you look at a strip-down of the car... these ones are prepared to race, and had some weight reduction at the non VITAL parts:
Any big impact on any of the shown (white and gray) areas is a problem!

Some impacts are simple to solve and carry no MAJOR problem to the cars chassis:

On the other hand, simple looking accidents are a doom ticket for the car:

Wanna know why? ok... look at the cross section on this part of the chassis of the car (the blue car impact, managed to crumple vital external longitudinal sections, together with the transverse bulkhead section!... bad luck x2) :


And if the damage is to the FRONT... then look at this section:

So pulling ALL the panels to place is... near impossible (those are high tensile steel extrusions)... and separating them to re-weld... well think about the "takumis" and the robot on a HOT template to build this part of the car... that's right! Once twisted ot badly damaged, leave it be.

How to spot problematic cars?
Poorly repaired cars will show immediate signs of trouble on the panel gaps. Uneven panel gaps (5mm on the left and 2mm on the right). Bonnet and boot may be deceiving as they are adjustable, so please center your search on the front panels and doors. If a door, after closed is gaping out and the other one in, you probably are looking at a side impacted and laterally twisted chassis.
Shift knobs that don't show themselves centered in the console panel mean trouble on a side impact too.

You see, after the repair at the workshop, it may "look" ok... but than take it for a good ride where the chassis suffers punishment and it will be out of alignment in minutes (and feel odd).

Good repairs will only show trouble under a deep mechanic analysis. In this case, the best option is to check it against Honda manual and check the measurements on all checkpoints and underpinnings.
Disguised repairs often come with a perfectly aligned suspension setup, new tires and brake pads. If this is the case, then someone is disguising a twisted chassis by masking uneven tire-wear and brake-pad wear. The best solution (besides having it inspected by a mechanic against SPEC underpinnings and assuming the car really is well aligned), is to make a test drive. On a empty road with enough space to recover from any unexpected behavior, leave the car running at idle in 2 or 3rd gear and floor it, then after gaining speed and still accelerating (with the rear suspension compressed) step on the brakes. The car should not trend left on acceleration and right on braking, or right under acceleration then left under braking. If it does, it's twisted.

Soft-top test : Unlock the soft top. The release should move the top slightly but with the same length on both sides (that's the rubber seal forcing out). Re-lock and check the pressure against your efforts...they should be the same.

Another test: Open the soft top, then park the car with one of the front wheels on top of the sidewalk and the remaining 3 on the ground...then close the hardtop and notice the slack. There should be a even or very close to even slack. REPEAT this test with the other 4 wheels, one on the sidewalk, 3 on the ground.

Hardtop test: a standard factory hardtop MUST fit perfectly and even on all sides.

The last problem to look for is rust. It in not very common, but it will become one if existent on the chassis...the same problem you have with a twisted chassis is close to the one you'll have when having to cut and weld parts of the chassis... remember the "takumi" and the robot on the hot template.

Now on to the "buy only IF covered by sales warranty" list:
Engine makes flapping noise - Check if this is form the valve train. If so, try to manage a slack check and adjustment...every Honda has some valve train noise. Most of them are related to slack and can be fine-tuned... on this case however, excessive valve slack will manage to hit the piston and bend the valve. Most problems on F20C engines are valve train related as it is also the most fragile part of the engine.
Engine makes tacking noise after heat-up - IF the tacking noise comes from the left side of the engine, than that's a faulty timing chain tensioner. The part costs from 100 to 250€ (depending on the country) and can be installed at home. If this is not the case, you can have a ticking engine and that's 1500 to 6000€ for a used or new one... or even more for a full blueprint and spec-up.
The low-end part of the engine is really tough and handles WAY more power output than standard... if you are going to spoil the car by way of Force Induction, the internals are good to close to 350BHP... and if using HIGH rpm turbo-boost ONLY you can go safely to 400/450 bhp.
Bare in mind that beyond 400BHP and the amount of torque involved in that (by ways of Forced Induction), the rear diff will go... a common replacement is the Nissan 300ZX diff.

Leave the Engine warming up and let it idle (you should hear a whistle noise form the front of the car for the first 20 seconds... and then a pufff as it stops pumping... that is the air pump to kick the catalytic converter into temperature to reach the efficiency level ASAP)  - After it reached normal operating temperature (the gauge should be light to 40% its way) listen carefully and see if it misfires  If it does it could be spark plugs ...so to track it out, rev it to 3000, step-of the gas and back-on again. If the car misfires under 2000/2500 turn off the engine, and ask to remove the spark-pugs. If one of them comes moisten then either a valve guide is letting oil in ([possibly due to being already bent), or the piston rings are history. This normally happens in cylinder nr 3 (that's the third one counting from the front of the car).

Finally to the "buy and reduce the price as you will have to spend money on fixing this" list:
Rear wheel bearings - Up till 2004 the rear wheel nuts where under bolted from factory. Honda issued a tech recall to service and tight the nut. Failing to do so will increase the tilt on the rear wheel bearings (more noticeable if the wheel offset is increased). My bearings failed at around 80.000km. Read about it here and here.
Lowered car - Lowered cars should not go over 2 to 3cm of lowering without camber correction. So if the car you are buying is lowered beyond 3cms (too much for road use anyway) check for a camber correction kit installed, otherwise consider changing all wheel bearings, suspension bushings and eventually a couple of slightly bent suspension parts.
Aftermarket wheels - Check the aftermarket wheels offset. Excessive offset main mean early replace to wheel bearings.... BUT if the offset is on the rims and not on the "spacers" near the HUB... then that car will corner a lot better without suffering fro vibrations at speed (common to low spec spacers). I have my car setup like that and I know I'll have to change bearing earlier... but it goes around bends like nothing else... and I find it a fair price to pay.
Suspension bushings - Check for worn bushings...consider a polyurethane replacement kit... rubber will go eventually and you should not expect it to live beyond 120k km (under factory setups).
Vibration on acceleration that stops on lift off - CV joints are worn. You can shift them (change sides) but if you are buying new, ask for a replacement or price drop.
SoftTop tears - You may have no tears yet, however, they tend to tear. Check the inner side of the soft-top for abrasion marks.

That's about it. Always bare in mind that if the chassis is bent, don't even fall in love with the car... it's doomed. If the salesman tell you the engine is the heart of the car, remember that you CAN swap the engine and repair it too... you can't do that with the chassis. So the good chassis is the car to look for.. the rest is negotiation around the warranty and price tag.

Saturday, April 6, 2013

Understanding Engines - Turbo vs NA... power vs response?! How does it all work.

This article has been spawn due to a comment on one of my youtube videos.
The video in question features a mighty modified Nissan Skyline GTR R34 VSpecII tuned to perfection by Mines. It's a true beast...probably the main reason why I don't like today's RenaultNissan GTR.
You seen the Nissan Nissan GTR...and called Skyline, was beautiful in all of its essence. That is why it managed the nickname GodZilla. Today GTR is no more than an vulgar Engineer wetdream built to impress Renault and trying to avoid Renault turning Nissan into "the factory that builds cheat wannabe suvs".
But this article is not about the GTR but rather the comment it self. After watching the video, the user added a comment in which he stated that a turbo car can be responsive. However he probably got so overwhelmed by the immense power of the car and it's extremely fast revving engine that he concluded that it was responsive.
So after a couple of minutes thinking about that I decided to explain the physics behind the induction system of an engine and the resulting consequences to power or response.
So why did the viewer got confused? You see, the car in question produces over 600bhp from 2600cc. One may say soooo, Place a big turbo in an ordinary engine and you have that same result... true..ish. The engine in question is the RB26DETT. And that stands for Racing Bred 2.6cc Dual over head camshaft Electronically manages fuel injection TwinTurbo....in plain English - The racing engine Nissan developed for the GT class cars, de-tuned for road use.
As a result, the engine is very high revving (because it is supra-square 86mm of bore against a short 73.7mm stroke). Now add 600bhp and extreme profile cams and electronics to such an engine, and you'll get huge power levels delivering in an explosive way from engine midrange up. In the video it's clear that the analogue needle in the car revmeter can't cope with such a fast revving engine.  
This however is not RESPONSE...it is power and torque(loads of it on a beautifully engineered, light engine). Torque is the work ability of an engine... for instance an engine with 1000nm of torque will pull a 3 ton car as easy as it pulls a 1 ton car. Power is the torque at high engine speed.
A diesel engine, is very good on Torque and very bad on Power so a VW PD130 1.9 will deliver 310nm of torque against 130bhp. A gasoline engine with VTEC would be very good on Power nd very bad on Torque... the F20C from the honda s2000 will produce almost 200nm of torque for 240bhp.

Analogy time:
Take for example 3 man. One with small muscles, one with normally developed muscles and one big guy with big muscles but also some fat. The muscle size will allow each to pick-up a certain amount of load (and this will vary in weight as bigger muscle pulls more weight), but bigger muscle will also consume more energy and have bigger movement inertia so the bigger they are, the slower they will move and more energy they will burn.
If you try a weight lifting contest, the bigger guy will win as the smaller guys will not even be able to pick up the weight. However, by breaking same the weight into 1kg packages and making the contest to move the entire volume from place 1 to place 2 10 meters apart, things will enter perspective.
In this second scenario, the less muscular guy will run fast back and forth without getting tired and will do this quickly, however lack of muscle will only allow for 1 kg package at a time.
The Big guy will probably pick up 4 packages at once, but will take longer to travel and will get tired in time.
The normal guy will be able to transport 2 packages at once, will move at an average speed and will experience some stress but will not get as tired as the bigger muscled one.

What I've just shown here in analogy is:
1 - A bike engine with very low torque and big horsepower, as the little guy with small muscles. Like a bike engine, it can't cope with big weight for lack of torque, but it will work very fast and transport the loads faster with ease (high RPM and as a consequence high horsepower).
2 - A normal gasoline engine with decent torque and horsepower figures, as the normal guy.
3 - A diesel engine with high torque but no horsepower, as the big guy without agility. It can pull a lot of weight with the same ease as a small weight, but the slow movement means it will take longer to work (lower RPM and as a consequence lower horsepower)

You might ask... ok, what about an analogy of a normal engine with a turbo. I would say that in that case, the normal guy injects quality steroids and testosterone, partially getting his muscles bigger, without growing bone structure and fat.

So how does this work? 
A normal engine is, in very basic terms, conceived by multiplying a simple assembly: a cylinder with a piston on it and some valves, the valves open and close allowing air through or not, the piston moves up and down changing the compression or reacting to change in compression inside the cylinder. This assembly creates a translation movement.
This assembly is connected to another one called the crankshaft. The connection is made from the moving part of the first assembly (the piston that travels up and down) to the periferic rotating end of the crankshaft, by something called "the connecting rod".
From this point onward, it's just a matter of how many of these are placed next to each other... a 4 cylinder engine will have 4 of these, etc etc etc.

In this first assembly (the cylinder and piston), the valves will open to allow air with gasoline in, while the piston travels down (this piston travel is called the stroke). Then the valves will close and the piston will travel up, compressing the air/fuel mixture (just how much of the volume of the cylinder gets compressed into the final result is what determines the compression ratio...11:1 means that the volume of air in the cylinder will be compressed into 1/11th of the original space), A sparkplug will create a high voltage spark, igniting the fuel and air under pressure. This result into a burst of energy liberation in the form of an explosion and its expanding gases...and that's what will force the piston down and produce power. After that, the exhaust valves will open, the piston will travel back up forcing the exhaust gases out...and the cycle starts all over again.

So if you think of it, the faster an engine can renew this cycle, the better it will work. So a good line of thought would be: ok... if the pistons and connecting rods, and the crankshaft are lighter, and the amount of length of movement the piston has to travel is minimal, that it will perform this cycle faster...and would be right. Bike engines, F1 engines, the F20C engine, the RB26DETT engine, and a lot of supra-square engines out there will rev very high because they have low stroke values and as a result of revving faster more air will be coming in or out of it. However, the shorter the stroke is, the less mechanical leverage exists to produce torque.
This is due to something called Linear Piston Speed. In basic terms, there are 2 things against the speed an engine works:
 1- The constant change of piston movement direction, creating huge internal structural stress in the piston itself. If not well engineered, it would develop cracks and disintegrate.
 2- Friction. The fact that a piston must generate compression and keep compression, means it will have to stress against the cylinder walls generating heat.
The best engines in the world, using special coatings and the best materials, are able to run at around 25m/s stable Linear Piston Speed and normally they can't top 28m/s, and even 28m/s is sustainable for some seconds only.
This Linear Piston Speed is created by the fast movement of the piston inside the cylinder...so every engine rotation, the piston will move 4x it's stroke distance.

So, for better understanding, if you increase stroke, you also increase the leverage on the crankshaft and generate more torque, BUT you will also be running higher LPS and, as a consequence, lower rotations.
This is the basic math about engines. Big torque means less rotation...less rotation means less high-end power (as power is a consequence of torque with rotation). Torque is the measure of rotating force, while horsepower is a measure of work per time unit...and since time unit, on something that keeps cycling is converted to rotations per time unit, we get RotationsPerMinute, or RPM into the figure of horsepower.

Check my next article about diesel engines vs gas engines for a better insight on the TorqueVsFuelVsLPS

Turbos compressors and stuff:
It should be clear by now, how an engine produces power and how it's volumetric capacity influences it.
Since an engine intakes air and fuel and then blows it into power, the more air and gas it burns, the more power it produces.
There are 2 ways you can increase fuel/air burn:
 1 - engine speed or rotation
 2 - engine size
This second one is the easiest one, but bigger engine means bigger everything and that includes weight and moving parts, that in turn add to inertia and frictions...not what you want in a moving parts machine, or a car. So the old comment "there is no replacement for displacement" is just as refined as pining nails to a wall with a sledge-hammer.

This is where forced induction comes to light. If a 2 liter engine displaces 2 liters of air on a rotation at normal atmospheric pressure, if you increase atmospheric pressure, than you force more air into the same 2 liters...for instance a 2 liter engine at 1 bar atmospheric pressure, will squeeze the same amount of air into it, as a 1 liter engine at 2 bar .
With different techniques, forced induction actually raises the atmospheric pressure on the intake, and by doing so it multiplies the engine capacity (it doesn't do so is a linear way, as air being compressed will heat and make the hole thing loose part of the volumetric gains obtained with compression).

Turbos, will use exhaust gas against a turbine that is connected to a compressor, that will compress air.
Compressors are chained to the engine crankshaft and use the engine mechanical force to compress air.
The centrifugal compressor is the compressor part of a turbo, linked to either an electric engine or the crankshaft, making it a kind of hybrid turbo....and some manufacturers are working on the electric turbo (a good idea that would eliminate the turbo lag problem).

So what is response? 
Well, response has to do with the time you engine takes to respond to your right foot solicitation and if it responds in the right amount of solicitation within a short time period. That has to do with a lot of stuff (including the engine design and lightness), but above all with fluid dynamics.
So what are the physics behind the response part?
The intake of an engine is controlled by a throttle assembly. It basic terms it is a tube with a choker that can be controlled from fully closed to fully opened. When you open the throttle, air rushes into the engine cylinders, when you close it it doesn't...simple.
The shorter and more open the path of air into the engine is, the better the response (the lighter the engine is, the better it will be to respond too). That is why the independent throttle body engines have great response. The entire throttle assembly is near the cylinders and since they each control one cylinder, the air flow is stable and  less turbulent.

On turbo engines however things get much more complicated. You see the air is being forced in by a rotating turbine that has inertia... if you just lift off and close the throttle, the entire intake will suffer a pressure spike that will force back on the compressor, trying to stall it, and this will degrade the compressor blades in time. That is why turbos normally use dump valves...its purpose is to remove this pressure and allow the turbine to maintain rotation (and health, for that matter)... turbos also have something called a Waste-gate that partially serves this purpose. The waste gate is used to control the rotation of the turbine (and so controlling the boost produced on the other end of the shaft), by opening or closing and controlling the amount of exhaust allowed to escape directly to the exhaust pipe and bypass the turbo... this does mean that in case of HELPING the turbine to slow down the waste-gate can fully open and facilitate the process.

On turbo engines, since there is no mechanical control of turbine rotation, your engine needs to produce exhaust gas to allow the turbine to spin (depending on the turbo type, size and construction it might have more or less inertia)...this produces a delay between your foot request and the power to become available... it will also come in an elastic way because the turbine inertia means a delayed spin-to-requested speed. Dump valves to minimize this effect by allowing the turbine to continue to spin, however this will not change the fact that on lift off, you produce less exhaust gas and as a result, there will always be a delay when you step back on the gas.
It's pure physics... Even in a PERFECT turbo that spins instantly to boost... the simple fact that the engine will also need to spin up to drive the turbo the even more boost means that the response from a 2.0 turbo running 1bar and full efficiency (acting as a 4.0 engine), will never have the same response as an Naturally Aspirate 4.0 engine...and this is VERY perceptible at low engine speeds, as the 4.0 has ALL the capacity there and the 2.0 turbo has no air to drive the turbo into 1bar of boost and so acts as a 2.0 with a bad exhaust as the turbo is actually working against the flow by obstructing on purpose.
And all this is, obviously, looking at things under a LAB perspective... because in real life, you have to consider that the important thing inside the engine is oxygen molecules... and that means that HOT air will have less oxygen molecules. And since air compressing warms air due to the force of compression and the fact that the turbo is very hot (due to the exhaust driving it), 1 bar of pressure is really NOT EQUAL to + 2 liters of engine.... sure you can add an inter-cooler, but this means MORE piping to fill with air until you have the right pressure, and no inter-cooler will be 100% efficient and cool the air down to the same temperature air as the outside temperature.

So turbo lovers that try to argument against this... just use the physics books you've ignored so far and admit the truth.

Can it be cured?
Sure! Are you rich?
Let me explain why: Most drivers don't have enough skill to steer the car using the accelerator...however the ones that have, prefer NA supra-square engines to turbo engines because of immediate response and correct proportion of response (no elastic effect) to drivers foot.
But what if you drive professionally is a championship where engines size and power are strictly controlled and capped? Like Rally for instance... the driver will steer the car with just about everything, including the throttle, but engines are small and compact, so they are turbo charged.
Well, they simply keep the turbine spinning independently of the throttle being opened or closed. They do this using an anti-turbo-lag system also called "Miss-firing system".
In simple terms, the system injects gas into the exhaust manifold and this will produce and explosion into the manifold.... past the already closed valves, making the turbine continue to spin..or spin even faster...that way, when you open the throttle back-on, no lag will occur as the pipes are already filled with air at the best possible boost pressure (controlled by a dump valve).
You can see this happening when you watch a rally car passing by and approaching a curve, on lift-off a series of "pooping" sound, together with some exhaust fireballs.
Why the "are you rich?" part? well, imagine the stress on the turbo by having explosions happen constantly all over your thing, light and gentle blades. Normally a turbo will not survive a season, being changed and serviced regularly...and unless you run on a racing budget, it will cost allot.

OK, so let's hybrid the turbo
humm not there yet.
A Hybrid turbo is a turbo that has a compressor or/and a turbine of different sizes. This is actually like balancing something for a specific usage.
You see, a turbo is not ONLY about pressure... it is also about flow. A 4 cylinder, 2.0 liter engine will consume 1liter of air every time it rotates (one cylinder pushes air and then compresses, one cylinder powers and exhausts, while other exhaust and pulls air, while other compresses and powers)... but at 6000RPM, the engine is actually consuming 6000 Liters per minute... and if that is supposed to be at 1 bar, than the turbo is actually having to pull 12000liters per minute of air.

If you make the compressor big enough, it will do that without problems, but this implies a bigger inertia to spin, and this will mean that the turbo will require a lot of air pulling the turbine... so this make the engine spiky, as the turbo will not produce boost until high revs and the, all the sudden will boost into it's operating speed.

To counter this, some people reduce the turbine, making it spin faster with less need of air... but this also means that the turbine will over-spin earlier and trigger the waste-gate to open to bypass the high volume... rendering the turbo unable to produce any more boost and while the rotation of the engine climbs, the pressure will drop.

So a hybrid turbo is actually a mild balance between when do you want the turbo to respond and up till what rotation vs engine volume do you want the turbo to "properly" feed the engine... they do allow you to tune the turbo to the engine to the usage, but they will not "solve the issue".

Wouldn't an electric turbo to the job? 
Well sort of!
See, the volumetrics that make a turbo produce big pressure, are worked around the size of the turbo and the speed it can turn VS the size of the engine it is feeding air to. A big engine at Big rpms consume a LOT of air and the turbo may not be able to feed the air at the desired pressure without "overspining"... that is the turbine spinning to a speed that causes a lot of cavitation on the air it is pulling and by so not being able to produce more flow at a specific pressure.
So an electric turbo would have to actually either drive a very big turbine, or spin very fast... ultimately melting the bearings.
There are however some works from VW that imply the next generation of cars will have an electric turbo always spinning to produce the low-end response and then a standard mechanical turbo will kick into gear when the engine is already producing enough exhaust!
That turbo engine I would love... let's see.

So sum up:
So turbo engines produce loads of power from a small package, however by having a turbo, response is sacrificed... that doesn't mean that, when producing power, it doesn't surge in huge numbers and make the revs climb fast...the thing is, this is not response, just power... and since the high rpms of a usable racing engine would drain the turbo out of his response range fast, turbos are more suited for torque figures than RPM.
Except of course the applications of bi-sequential-turbos like the Rx7, or the biturbos on inline 6 as te supra and the skyline... as an attempt to have the "best of both worlds".

Sunday, March 3, 2013

The new Ford KA... Boy I miss the URGLY brilliant old Ka

As with most cars on sale today, the new ford Ka is a beautiful looking thing.
However unlike most cars today, this evolution means a leap back in quality.
When I drove the car, I was immediately disappointed with it. At the time I really didn't understood why, but it just fell un-involving, disconnected....plain cheap.

You see, I've driven the old Ka a couple of times, but more important, I drove it's big brother the Fiesta MK4 for years...and they were practically the same.

Let's make a big X ray. of the projects supporting the Ka, first:
Back in 1989, Ford unveiled the BE-13 chassis on the 3rd generation ford fiesta.
The BE-13 was an important step in terms of chassis engineering. Most people forget the simple fact that during MK2 fiesta was comparable to a facelift of the MK1 Fiesta. In both Mk1/2, Ford had to undergo some heavy reinforcement engineering when they decided to launch the XR versions for the boy-racers. That was taken into consideration while developing the Mk3 chassis. 
Not perfect, the BE-13 was competent and involving. 

1995 came and the BE91 chassis with it. This is an important mark in Fords history. The BE91 was used first in the Mk4 fiesta and was essentially the Mk3 (BE-13 chassis) with revised suspension. It quickly became the best in its class, but more important, it just added to the Ford brand a distinctive signature of driving pleasure that just wasn't there as an experience to the entire brand (it used to be just a couple of model property). It just felt like Ford had unleashed their engineering team from the rally world and allowed them input into every other project...it was just wonderful.

The most important thing about this chassis, was the fact that, due to its brilliance, it was widely used. The BE91 was the basis of:
The MK4 Fiesta and The MK5 Fiesta

The Mk1 Ka 

 
The Mk1 Ford Fusion

 
 The Mk1 Ford Puma

The Mk1 and Mk2 Ford Courier

 and the Mazda 121!!!

This spawning of projects bases on this chassis is not only a proof of versatility. The Puma was a small-sports concept, the Fiesta Techno has a sporty appeal to it, the Mk5 Fiesta had spiced-up ST versions and they all fell involving and responsive.
I drove the Mk4 Fiesta from 1997 to 2004. The car was probably the best driving experience for money I've had so far. I even took it to the track and establish a point of matter against 2 tuned Mk4 Golf TDi, a tuned Peugeot 307 Gti and an alfa that was trying very hard not to self disassemble while not rusting from bend to bend...and of course that left no room to maintain braking ability. All the cars (tuned or non tuned) gave up and parked after 2 laps (most after some scary handling issues) mostly without brakes. This is arguably due to being badly equipped, or simply badly balanced chassis, forcing them to use the brakes more often...the mk4 Fiesta equipped with nothing more that tarox front discs and kevlar front brake pads, recorded over 12 laps and 3 of them were even video-taped and are available on youtube.
So regarding the BE91 chassis, I can say that I know it like the back of my hands.

So that was the great big disappointment on the first meters I drove the MK2 Ka... I felt No BE91... or none of it's evolutions... I felt lack of what has been branding Ford since 1995.

You see, The Mk4 fiesta was Ugly. The Mk1 Ka was even worse... I mean if the fiesta looked like a soap, the Ka would only make sense in Tokyo, and even there, it would not live to be cool for more than a week.
I was very critic about the Ka design... and the new one is just as beautiful as a Fiesta, with in turn is just as beautiful as a Focus.

 These are the Mk6...

...and Mk7 Fiestas

And the Mk2 Ka:
  
 Is just beautiful.

I mean compare the Mk1 with the Mk2 (on the design side alone):
 
 There is no other way to say this... the old is UGLY and the new one is BEAUTIFUL. 

The problem is that the looks, are nice when you show off, or when you approach the car. But when you drive it, they have no part in the rewarding experience...and regarding the rewarding experience the Mk2 is just BAD! Cheap! Plastic! Un-involving! It's one of the worse ford's I've driven and that included old transits!

The one to blame? Meet the Barbie Car:
 
Yup.. That's it! A brand known for creating robust and involving cars, took one of the best chassis it has ever created and replaced with the barbie car, from the brand known for creating...cheap un-involving, everything but robust cars.

The minute I knew this, it all made sense. I know why I would never ever buy a Mk2 ford Ka...its because of the lack of Ford in it!