Have always heard we lose horsepower when using active handling - "on" vrs. "competition" mode or "off".

Anyone know how much hp is lost, and/or the difference in 1/4 mile times.

C5 M6 3.42

 

ttt

 

No takers to your thread probably because you can't quantify the loss of hp. But true traction control will kick in with loss of rear wheel traction and reduce power from the engine. The competition mode only disables the traction control while active handeling is still enabled. With active handeling off both traction control and active handling are disabled.

 

Don't know any hard numbers such as you're asking, but I can clear up a little confusion with the terminology you're using. This might help in narrowing down your question.

- Positraction: Refers to the rear differential. Is not associated with Traction Control or Active Handling in any way. Doesn't affect horsepower or torque. Maybe during tight corners, but I don't know how you'd measure this.
- Traction Control. Computerized throttle intervention when the computer deems rear wheel spin.
- Active Handling. Computerized intervention when the computer deems the car is losing control.

Then there's this thing called "Torque Management". All A4's have it. Can't get a clear answer as to whether M6s have it. Some say yes, others say no. Designed mainly to extend transmission life. Timing is retarded for a fraction of a second during the shift event.

Many turn TM off. I did. Makes for a harder shift. Some people though, have posted and shown that it really doesn't have much affect on the performance. They've demonstrated with dyno graphs that the drop in torque is really minimal and truly very brief(fractions of a second).

The cool thing about this forum is that if/where I am wrong with the above description, someone will surely pipe in with a clear correction.

 

No horsepower loss with posi-traction. As someone said above...Positraction refers to the rear end and has nothing to do with active handling or traction control settings. Positraction consists of a set of clutches that start to drive the left wheel when the right wheel starts to spin.

Now...active handling / traction control settings..."on" vs. "comp" vs. "off". If you have TC on, the computers will pull fuel and timing to attempt to keep you from losing traction...or spinning your tires.

"Comp" mode turns off traction control thus letting you put full horsepower / torque to the rear wheels (torque management limited), but keeps active handling engage in a stand-by sort of way. If you get too bent out of shape active handling will take over.

"Off" mode turns both traction control and active handling off (still torque management limited). The car is entirely in your hands.

 

Ah, ha... that's what I thought centrifigual clutches in the differential distribute wheel spin. That's old school positraction - do we have it?

I can see how "competition mode", or "off" would help road racing where the driver may want to let the rear end slide out a bit and how the engine regulating power/acceleration in a slide may help control it.


My question is mainly related to all the difference of opinions we hear from Vette owners at the 1/4 mile drags. Almost everyone thinks you will run faster with "Comp" or "Off" modes. First of all, don't we have some form of mechanical posi-traction inside the differential?

Secondly, I can see how limiting power in a sliding turn can help control the car, but unless AH limits power to selective wheels can't see how it could control straight ahead traction (unless you just get sideways lose and it just shuts down all acceleration). The confusing part to me is if all active handling does is try and control traction by cutting power then it doesn't equalize the difference in wheel spin at all.

Do guys run the 1/4 with faster times with it off or in comp?

One other question. There was a fella a few weeks ago who lost his car into the wall at the drags and found out the hard way insurance doesn't damage during cover racing. For that reason, I'm reluctant to even use "competitive" mode, but maybe I shouldn't be if it provides traction control somehow without restricting power. Again, this whole restricting power thingy has me baffled unless AH has the ability to select power to each wheel individually. I'm skeptical of this and think we must have some sort of clutch device in the diff.

In short, I think the AH is a benefit in road racing, but for just straight ahead traction, other than it's ability to simply shut the car down if it's wildly lose... it's not providing traction - the internals in the diff. are.



Thanks,

 

Yes, we have "old-school" positraction in the transaxle.


You will run faster in "Comp" or "OFF" mode versus "ON" since Traction Control is not trying to limit the wheelspin. We have mechanical posi AND computerized Traction Control AND Active Handling.

Right...Comp mode or Off mode would not provide any difference in 1/4 mile times. Active Handling does have the ability to take over control of power / braking independently to regain control of the car if it gets wildly lose. AH computes the speed differentials between each of the four wheels and acts accordingly. Even in Comp mode there is a possibility to lose it and wreck the car, but I don't know what the limits are.

Point of note: If you take it to the track you better be willing to cover what you break (be it the motor, tranny, or (heaven forbid) the whole car)!