ldamelio

I've always been generally aware of the ability to reprogram software or 'chip' a car for performance gains. I never paid much attention to this as all my cars have been practical family haulers or conservative sport sedans (A6). I'm now in a glorious 718 CS and enjoying all 350 hp. I see software modules advertised that will get me into 911 CS territory (420 hp) without requiring mechanical mods. I don't 'need' this but there is a certain temptation there.

So, my question in a general sense:

How do such mods affect durability and drivability of a car in general?
If this is so easy, why doesn't Porsche do this at the factory? Squeezing 350 conservative hp out of a 2.5 liter 4 seems to already be a feat that pushes stress on the engine components. Is it just a matter of positioning a car in the hierarchy - ie keeping Cayman S power under base 911? I'm seeing that he upcoming GT4 may get a detuned GT3 flat 6 - is is just a chip away from a 'budget' GT3?

Thanks in advance for feedback.

JCviggen

Depends on the individual tune. With a turbo engine especially, it's really up to the tuner what kind of behavior they end up with as they are in control of the boost curve. Torque mountain with lots of shove but a flat top end or a smoother curve with a progressive increase are both possible in theory.

Because they know exactly how much power they want and they program it to do that. The margin left on the table allows the ECU to compensate in order to deliver equal performance in hot or cold weather and also for general efficiency reasons.

It's not that much, but there isn't much of a track record yet for this engine especially when tuned. Compared to modifying an NA car which is generally harmless to the engine, tuning a turbo car does considerably increase stresses on many components, raises temperatures and reduces efficiency. Generally though, when using a reputable tuner, the risks are small.

Nobody knows for sure what engine it will be, how accessible the ECU will be, how Porsche will downtune the hypothetical engine or even the price point of the car.

ldamelio

Thanks - quick and detailed reply before the ink was even dry on my post! Greatly appreciated.

Krampus

Well if you haven't seen this already it has some good information that may answer your question.

JT74911

Just a word of warning. I have a 2000 Ford Explorer. In 2003 I added a chip to improve towing capabilities. It passed California smog with the chip until this year. Now I had to go to a Star Station for my test and I failed - computer modification. I've been to a Referee who said I had to remove the chip and get the ECU re-flashed, then return to the Referee. I have the re-flash scheduled this Wednesday. Most dealers were booked for re-flashes 3 - 4 weeks out. The first smog tester implied that VW was to blame.

Krampus

Yeah I have dealt with this type situation before as well. County I lived in did emissions, and the county next to it did not (which had a track we raced). Tune on the car was just rich enough that it would fail. So I had a spare ECU around (this car was not a daily driver) with the stock tune. I would swap it out for testing, and swap back later for the ability to drive it to, and from the track with the performance tune. Later I moved to the county that did not have emission tests, and never had to do that till the day that I sold the car. Things like this have been going on forever. Some people just find a way around the rules. Not to negate the need for standards such as this. Just not surprised when its found that someone did something to get around the rules somehow.