I thought AHS was supposed to prevent rear wheel spin. From a stop, I went less than half throttle and unintentionally left 12 foot burn marks w/ the rears. AHS was fully on-- not off or in competition mode.

Did it fail? Is there a reaction delay?

I also notice wheel spin when accelerating hard and the A6 (w/2.73 axle) shifts from 1st to 2nd. Again, where is the AHS?

 

TC controls wheel spin.

 

True. And when AHS is on, TC is on, unless in comp mode.

So to clarify, with AHS engaged, why didn't the TC kick in?

 

It's a pretty relaxed TC from my observations. I know the one in my Mustang will shut fuel off immediately (which I don't like at all). The Vette seems like it's not doing much at all as far as limiting or ending the spin.

 

if it was what the ECM thinks is excessive spin TC will kick in ,if ya start to get out of shape [side ways] AH will kick in . they call it 'save your *** software' if ya got a LOT of seat time you can run with AH/TC off but if ya dont have a LOT of seat time you will never save the car when it starts to spin at speeds

 

You can turn TC off while leaving active handling on.

 

Yes, of course, and that's called "competition mode."

Again, to reiterate, I was not in comp mode, had AHS on, and TC did nothing noticeable when I got wheel spin off the line.

At the expense of tire wear, next time I'm out in the middle of nowhere, I might try a really agressive start w/ AHS on to see if I can get TC to activate.

 

No you can turn off TC and leave on AH without being in comp mode
Mike

 

Oops, I did not know that, thanks for the correction.

I'm still pretty sure that I had both AHS and TC on that day. I was just driving in the neighborhood, had not been messing with the AHS button, did not have the AHS warning light on, and did not see any warning messages in the DIC.

It's possible that I may have inadvertantly turned TC off and not noticed, I admit.

Now the question becomes: what's the difference between comp mode vs. turning TC off and leaving AHS on? Does comp mode eliminate ABS as well?

Think I'm even more confused!

 

Correct - TC Off AH full on - One press of the AH/TC button. Light on the IP - showing TC off.

 

if its an automatic comp mode stops it from down shifting when you floor it into a turn or coming out so it doesn't go sideways but you can still spin the tires going straight

 

Comp mode shuts off TC but leaves AH on in a 'reduced' capacity allowing greater tolerances for sliding or drifting your car (such as you would want on a road course).

I always shutoff TC when going WOT but there have been a couple instances when I forgot to do so. Even with TC on I can still 'over power' TC and spin my tires.

 

WOW slow down here............

Car starts with TC and AH both on. Push button TC goes off push again goes into Comp mode, hold button down while in comp mode turns both TC and AH off. When in comp no yellow lamp telling TC is off, but it is. Otherwise TC off always has the yellow lamp.

Comp mode is no TC and limited AH

No TC with AH still on is full AH compared to Comp mode.

Any questions?

Cold tires will always spin even with TC on.

 

i have done my burn out with nothing turned off

 

I believe the computers step in AFTER the computer senses an event. IE: once the tires start to spin, at a certain point the computer steps in the limit spin.

 

ABS always on no matter what mode.

 

You CAN overpower TC

 

well thats good... Because after i got predator tuner installed on my car i seem to have permamently lost that TC option you guys all seem to talk about... Since i didnt have my car for long before i got predator, how well does the TC actually work? In the rain if lets say you gave it half throttle on a straight road with everything on does your car bust out in a p-slide? or can you feel the TC actually take the power away and limit some of the slip?

I am thinking about getting a real tune because A. Predator sucks and B. I want my TC to work again...

 

Traction control, to the best of my knowledge, utilizes the wheel speed signal from your ABS sensors to determine if there is a speed difference between the front and the rear tires. Should there be one, it will deduce that the rear tires are spinning and will come into play.
What makes our Corvettes so special is that they have a much more "performance oriented" traction control than other cars. My best efforts at elliciting wheelspin in every other car from Ford, GM, and Mercedes Benz, have resulted in a very brief "chirp", followed by the most dramatic power loss imaginable; the ECU on those cars will literally close the throttle blade as soon as it thinks you are about to do a burnout. On the Corvette, TC WILL allow a small amount of wheel spin for a brief period of time before it comes on.
Once TC comes on it will do two things: first it will retard ignition timing, causing a small power loss. Some times this is enough to allow the car to regain traction, or, my favorite, cause it to spin the tires gently while accelerating at a good rate.
Should ignition retard fail TC will physically close the throttle blade. This is VERY dramatic under some circunstances; it manifests itself as a drastic loss in power. A good example would be attempting a burnout with TC on; it will spin, then bog completely. If you stay on the gas the throttle will open again slowly and the car will either regain traction or it will repeat the cycle if traction is not available (say, on a wet road for example).

A problem arises when your car has much more power or much less traction than the factory intended it for. Guys with heavy mods report that TC is no longer adequate to keep wheelspin under control. Under those conditions the only solution is to obtain better tires.
My car makes 400 at the wheels. With 18K miles the factory run flats would spin every time I got on it in 1st gear. I replaced them for Michelin Pilot Sport PS2s and I can now jam the throttle in 1st at any speed and hook up so long as the road is dry, straight and reasonably warm. When modifying anything on the car it is important to look at it as a whole package: you can't add power without adding traction, or increase grip without increasing dampening and spring rates, or increase power and grip without increasing the clutch capacity, or strengthening the driveline, etc... People who do that often find that their cars break parts, their clutch slips, the power becomes unuseable, etc etc... I should know: in my quest for more horsepower in a Subaru 2.5RS I blew 4 engines, broke 3 transmissions, a rear diff and a halfshaft...

 

I have a 07 automatic. I tried to do a little burn out in the corporate parking lot last week and forgot to kill the TC. The car fell flat on it's nose as if the fuel got pinched off. Whenever I want to burn a little rubber, if I kill the TC, they spin like I am on ice. If TC is on, forget it.