multi21

I've got a question about something I experienced during an autocross this past weekend. I use left foot braking during autocrosses and found that when I tried to get back on the gas while still having the brake depressed, the engine would not wind up. It wasn't until I got completely off the brake that the engine would spool up. It was as if the engine management system would not allow fuel or spark to engage with the brake depressed.

Why is this? My other cars didn't do this. Although I don't use left foot braking on big tracks, it's a hold over from the kart racing days and allows for fast laps as I'm able to never let off the accelerator during an AutoX. It's highly unusual for a car as adapt to track work as a GT3. Any thoughts on this?

Holger B

Welcome to the world of e-gas (aka throttle by wire).

Nordschleife

A proper tuner can disable this feature of E-Gas. Its part of the legacy of Unintended Acceleration, which we now know was a hoax.

R+C

Bob Rouleau

Since about 2000 all Porsches have E-Gas. The gs pedal is not connected to the engine, rather to the engine computer. If you apply the brakes while pressing on the gas, the computer assumes something ha gone wrong and cuts the power after a second or so.

If you lift off, apply the brakes and then press on the gas, while still braking, power is not cut. I nearly wrecked my GT2 discovering this.

Best,

Nordschleife

very important to suss this one out, when ice dancing!

R+C

Flying Finn

How big of a deal it is to disable? Once I get my hands on a GT3, I definitely need to have it disabled.

Carrera GT

There are threads aplenty on this topic. Suffice it to say that even in an autocross situation, if you're asking the car to linger with both throttle and brake pedal long enough for this "feature" to take effect, there's something else going wrong. I don't find it an impediment, but I'd rather it wasn't there -- when I run afoul of its influence I've never been happy with the results.

Bob Rouleau

R+C - yes, important indeed. I decided to try left footing my GT2 in a hairpin corner which found the car "between gears" and off boost, you can imagine my surprise when I found myself "losing power" in the middle of the corner. Major counter steering was involved and the guard rail was very close. That ended my left foot braking career on modern 'drive by wire' cars.

Nordschleife

Its no big deal if you know how to do it. My Motronic man knows how, but he is one of the best in the world. As I don't see this being offered by all the chip tuners, I assume that it isn't just a matter of changing a flag.

He also makes what we need to turn off the stabilty system, just a switch, really.

Needless to say, this particular Motronics expert is in Bavaria, which is not convenient to everybody.

R+C

guykoken

What stability system?
996 Gt3's don't have one.
Richard Bain

Flying Finn

There's nothing going wrong, just the type/style of driving I'm used to.

I don't use LFB on autocross type of situations, mostly in a long sweepers where I want to settle or "guide" the car or just braking with left foot and then applying throttle while still braking (although it seems in that kind of situation it would be ok).

Thanks for the info. I need to search the archives, maybe there' more infor about US tuners. Anyone know place that does it?

va122

Pretty annoying as I found out in the middle of a corner as well. I found that this feature doesn't engage until the brake is engaged over 10-15% after which the revs will go to idle.

enthusiast

I believe the comment was in regards to the 996 model in general and the PSM which was standard on all but the first model year North America spec cars.

ArcticFox

I found that in my car, the E-Gas interuption only comes on in certain situations. If you are on the gas and brake, it comes on...however, if you brake first, then roll on the throttle, it does not come on! eg: brake for a corner then roll on throttle to balance the car...no E-Gas cut off. That is my experience...it only seems to cut off if you have gas first, then brake....not brake first, then gas. I dunno, maybe I am a dumbass, but that seems to hold true on my car.

Flying Finn

You're not a dumbass, look what Bob wrote earlier, that's how it supposed to be (or Bob is an dumbass also).