MrEracer

I normally turn off my traction control but do not use C/M on the track. I am an aggressive track racer but have not tried running in C/M. I do not like the idea of the car doing uncommanded maneuvers. I am pretty good at running on the edge of traction and recovering from impending spins. What is your experience in this mode for those with lots of track experience? Will C/M help or disrupt your technique at the traction limit.
Shirl

TedDBere

If you're trying to win, then don't use it...you haven't been using so far so probably don't need it. Just ABS.

If you're just having fun and practicing your lapping, then keep it on. IMHO.

I find that if people have to ask then usually they need to leave it on. But since you've stated that you have lots of experience runnning with it off then stay with it off so you don't start to lose your seat-of-the-pants feel for the limit.

varkwso

It sometimes keeps you from doing what you want the car to do. At other times it keeps you from doing things you do not want to do. I agree that keeping it on for fast lapping is a "safer" and turning it off will make it faster - all things being equal.

I mostly keep it on - it is an odd feeling to feel it kick in though!

Jim 47

Shirl:

Comp Mode is an good tool for some drivers to use in the learning process. It is an insurance against a possible spin and provides some degree of mental assurance that your mistakes can be corrected before becoming disasterous. It will be the greatest benefit to the "agressive" driver who thinks that blasting into every corner is the way to drive. This said, the CM can't correct the laws of physics, so one should not rely on it to bail you out of something really stupid.

If a beginner approaches this sport by increasing their speeds/lap times/ agressiveness in very small increments and approach the "limits of adheasion" very slowly, from "plenty of adheasion" up to "I can feel the tires loosing grip", then that person will develop the skills and experience to be able to handle the sliding and slipping situation when it occurs, and reliance on the Comp Mode "crutch" will not be necessary.

When I got my 2000 FRC, I did use the CM as insurance against some stupid mistake that I could make, but I quickly stopped using it because it was intruding into what I wanted to make the car do. I strongly believe in approaching the limit of adheasion from the bottom and SMOOTHLY using the steering, brakes, and accelerator to maintain the balance and tire grip at the maximum. I hope this helps to answer your question.

Jim Helm

Z06_Bob

Sorry.. Misread the thread.

Bob


[Modified by Z06_Bob, 12:50 AM 5/1/2004]

Jim 47

Z06 Bob: We are discussing the pros and cons of Competition Mode being used - - or - - the Active Handling system(and thus the traction cantrol) being turned OFF, NOT the Traction Control or the Active Handeling "ON" Mode.

So why the

You obviously have assumed that some of us long time road racers are misguided enough to have the Active Handeling (which includes Traction Control) ON when we are on the track.

When I said I had stopped using the CM (Competition Mode) I meant that the Active Handleing System had been turned OFF completely, NOT that I had activated the Active Handling System. I hope this calirfies the situation for you.

Jim Helm

QUIKAG

A few years ago, I used competition mode for my first few track events. After that point, I've had it off ever since. You become a much better driver with it off because it forces you to be SMOOTH.

Z06_Bob

Ok.. Sorry.. Misread. I thought you were talking about traction control, not competitive mode. I don't know how I messed that up. I do know that traction control is off when you are in Competition mode. Doh!

Bob

Mike Schriber

This question has been raised a number of times. Before I switched to the race car, I would always run my Corvette in Competition Mode on the track. My thinking was this... I was on the track to learn and have fun. I wasn't trying to win any races. I certainly wasn't out there to damage or wreck my car. That was the foremost reason I decided to leave it on. A little extra speed or learning wasn't worth the risk of serious damage to the car.

The Active Handling system can actually work well as a learning aid... if it's activating all the time on each lap, you're not driving the car right. If you can lap fast and smooth, the system will usually not activate. However, if you really mess up, the system can often save your bacon. I remember getting a little pucker factor one day going over Magic Mountain at Buttonwillow. I'm not sure what got me, but I lifted. The car instantly started to come around. Before I knew it, the computer brought the car back in line and I was on my way. I might have been able to save it, but it's not likely and that's a bad place to go off.

You know the commercial... I liked it so much, I bought the company. Actually, my business partner and I designed the TracActive Controller so I wouldn't have to hold down the button anymore. I never even think about it anymore!

Mike :flag

StArrow68

Mike and all thanks for the inputs. Since I'm relatively new at Corvette's and Tracking I never thought to turn the system completely off for just the reasons you outline in your lead in. Also it helps that I work for the outfit that produces the gyro in the active handling that measures Yaw and that is what got me into the Corvette in the first place. Discussing the gyro with engineers that know Yaw but don't have much clue about racing gives you a better understanding how different companies implement stability control and the Corvette system is fairly unique. That being said I'm sure I will also turn it off at some point having been through the phase where I was letting it do some of the driving and gotten to the point where I can go pretty fast and be smooth enough to 'drive around it' since I have learned what kicks it on most of the time. It is also prone to trashing tires but that is a lot better than trashing the car.
However, at Sears Point several weeks ago I had it kick in somewhere other than at what I'll term simple under or over-steer, entering or leaving a turn. I was in turn 1 just under 100mph later in the day and lost some concentration so I dropped my right rear off the pavement edge, it started to go but without so much as twiching the wheel either direction and staying on throttle up the hill it slapped me back and forth four times really hard and so quick it was just a tug of the wheel in each direction and I too was on my way to brake, downshift and turn in for turn 2. Although I was real 'woke up' at that point.
I've now spent a few days in open wheel cars where part of the training is to get the proper slip angle and it's a lot more fun than depending on the system, still I think I'm going to appreciate that little gyro for a long time to come.

Jim 47

I have noticed that the Competitive Mode likes to intrude when you put the car into a prolonged high G "Power On" turn. Several years ago at VIR I cracked both rear rotors (Yep rears) because the CM was applying the rear brakes to correct a high G situation that really didn't have to be corrected. (You really put a lot of heat into the rear brakes when both the power and the brakes are being applied at the same time). After cracking the rotors and then replacing them, I turned the CM and the Active Handling OFF, and was able to run quicker laps, and have never since destroyed any rear rotors.

Jim

TooManyIDs

C/M will disrupt your technique at the traction limit.

I leave the whole system on for a couple laps while the tires warm up, then it goes off.

Midwayman

There was a c5 at Road America that reportedly melted its rear calipers. That was a real head scratcher for me, but I think you've explained why it probably happened. I had never even thought about the heat issues from its rear brake use.

Timz06

Bumps and dips in the pavement will also activate it. I can think of several places at road atlanta where it will activate.

adamsocb

This phenomenon seems to be related to how much stick the tires have. The Active Handling system uses an accelerometer (G-meter) to measure lateral acceleration, plus steering wheel angle, and wheel speed to feed the computer. It basically determines if the car is under or over steering by comparing the lateral acceleration to the steering wheel angle. In normal Active Handling mode it uses power reduction (traction control) to help control the car, but in C/M traction control is turned off and it just uses the 4 channel brakes.

When I was on the stock coupe size street tires (Kumho MX's). I used to run with C/M on. During a good lap it would not come on, but as others have said, it saved me from a few mistakes.

I recently switched to 275 front and 315 rear Kumho V710's (DOT slicks). The extra traction and G-forge generated completely fooled the computer. It was applying the rear brakes in every hard turn and not releasing them until several tenths of a second out of the turn. With this tire combination I had to turn it off.

My conclusion is that if you have a stock car with stock size tires, Comp Mode is a great tool both to stay out of trouble and for learning a smooth line. If you can run a fast lap in C/M without triggering the system, then leaving it on is the smart thing to do.

Once you start to modify the suspension and tires away from what the computer program was designed for it will no longer work as designed, and it will need to be turned off.

This sounds like an opportunity for the tuners, if they can find a way to hack the active handling program for modified cars.

LTC Z06

What everyone above has said is correct. I too was toasting rear rotors until I turned it off, but what made me turn it off was going airborne! Nurburgring has two places that you can have all 4 tires briefly leave the track and the system will think it's on ice when this happens and you land with all four brakes applied, it was very disconcerting to say the least

VetteDrmr

Shirl,

Based on your first post, I wouldn't transition back from no help to CM; you'll see (as others have posted) much higher brake temps than running w/o assistance.

I autocross, and while brake temps aren't a problem, I found the system engaging at just about every turn. Maybe it's just my driving is that bad , but I turned it off the second event I tried it, and my times kept going down. Plus, my rear brakes were much cooler.

HTH, and have a good one,
Mike

Mike Schriber

Hmmmm... I just want to chime back in and comment on the recent posts. This is the first I've ever heard of anyone trashing rotors or melting components because of Active Handling. If the system is activating that much, something else is wrong.

I can't really judge anyone else's experiences, but I ran my '99 C5 (first generation Active Handling) extensively on the track in Competition Mode. When it was being raced, the car was setup with Goodyear GS-CS1 slicks (on GS wheels) and run with Bilstein shocks. I never had the system activate due to high G loading. It came on very predictably. The car was run on a number of track, including ones with fast, high G turns such as Willow Springs and Spring Mountain. At Spring Mountain in fact, I had some much grip in turn two (long fast left hand sweeper) that I had to back off due to engine oil strarvation.

I ran some of Rupert Bragg-Smith's Corvettes at Spring Mountain (second generation system) with stock tires and never had any strange system activations or brake issues on those either. I'm not sure why some people have had issue, but it could also be a driving style issue.

Your mileage may vary!

Mike :flag

LTC Z06

One of the main reasons our rear brakes were overheating is for 02 and up GM added more rear break bias, your 99 had less.

Mike Schriber

Opps... forgot to mention that I'm also running the DRM brake bias spring.

Mike :flag