TRSCobra

Did my second ever autocross with my 2006 Z06 and once again AH caused me to completely lose control of the car after a slalom section. Last time was on the stock alignment specs and stock runflats 3 years ago, this time I'm on 285/345 MPSS, lowered on stock bolts and Pfadt Performance street alignment specs.

The first time was in the dry and it made me go all 4 off course, the second time it was 35* out, wet, and snowing.

I know there's only so much you can expect in these conditons, but the C5Z and C7 corvettes there didn't seem to have any problems. Am I really that bad with this car is is this potentially an issue with my active handling?


I turned the TC/AH off and had a spin later on but not nearly as bad, and I was pushing the car harder.

harrydirty

If you turned off the TC/AH, then it's just you and the car. Have you spoken with the other drivers to see what they think? Most drivers, especially the good ones, are eager to share their knowledge and will mostly likely help if you ask for advice.

Good luck, this is an addictive sport.

apex26

I've only done two years of autox to fill in between track days, so there is a wealth of experience here that could comment. My humble experience is that even in competition mode, it is WAY to intrusive on track and autox. Slow down a tad, and learn to drive with it off. After doing that, I set two FTD's last season--(surpassing lots of guys who leave theirs on). Some of us are old fashioned purists, don't go for "electronic rev matching", paddle shifters, and computers driving the car. In the end, it's a choice between driving your way to the front, or buying your way to the front. Just one purists opinion...hoping to hear others.

Sox-Fan

If Active Handling is left on, it'll do that. The car is doing the best it can to decipher your inputs, the wheel speed sensors, and the yaw sensor, then straighten out the car. It's not human and it has no eyes, it cannot see to know you're jerking the car all around on purpose, and/or sliding for a reason. Yes, it is more intrusive than the C5, and less refined than the C7. The programming was the best available at the time.

Shut it off, then drive it that way. Your mistakes will be your mistakes, and you will not have the additional overhead of fighting with the car in what the car thinks are perilous conditions. Yes, you may spin a time or two starting out, but you will be surprised at just how fast you get the feel for it when it is just you driving. In the end you'll be a better driver for it, and your brakes will last longer.

JLZ06TR

on my C5Z ive had the active handling warming up message come up in the middle of a run. Caused me to spin during a slalom and thats because when that message comes up, you essentially just lost the system and if you were leaning on it at the time, then ur going to slip. I found the key is one of two things. One is to not run active handling at all and the other is, once the system is warmed up, do not shut off the car between runs. my understanding is that this has to do with some calibration the car does with the wheel sensors that resets itself every time its shut off. So once its done, dont shut off the car. Or just dont use it at all.

Bill Dearborn

Active handling calibrates the steering sensor in relationship to traveling straight ahead after each engine start. You have to travel in a straight line for some distance above 6 mph for it to calibrate. I think the distance is about 200 ft. It affects the C5 and C6 and although I haven't checked I suspect the C7 is also affected. They do this to compensate for wear in the steering elements over the miles and years. If you are depending on AH and it suddenly goes into a calibration mode it is gone and can't help you any more. That could result in an off course. The early C6 cars had an issue with the steering sensor connector where the connecter pins would stop making good contact and the service AH warning message would come on. As soon as that happens AH goes away again which can result in an off course if you are leaning on the car and depending on AH to help correct an oversteer or understeer problem.

When AH is working correctly it most likely will not result in an off course. In turns where the front tires are understeering it is going to be applying an inside brake to cause the car to yaw in the direction the driver is turning the steering wheel. In turns where the back end starts to swing out it will apply an outside brake to reduce the yaw rate to keep the car pointed where the steering wheel is pointed. If the driver is using the throttle it may reduce throttle first (faster reaction time if the vehicle is moving fast) and if that doesn't provide enough correction it will start using the brakes to yaw the car. The result of the reduction in torque or the application of the brake is to slow the car and keep it on the course Vs throw it off the course. Of course if the driver starts to do all of the wrong things to counteract what AH is doing then all bets are off. In some cases AH can actually get you around the course quicker but you have to know how to use it. Being able to apply one brake it is capable of doing things the driver can't. A knowledgeable driver can use it to accelerate off particularly difficult slow speed corners with the rear wheels spinning some and AH keeping the car straight by alternately applying a single brake.

AH can be used to improve driver response. The smoother you are the less it needs to correct things so every time you feel it intervene there is a good chance you screwed up. Work to reduce intervention and you get smoother and we all know that smooth is what wins autocrosses. Once you understand what smooth is by using AH to tell you when you aren't being smooth turn AH off and go to town.

Bill

strano@stranoparts.com

I can't see the video but looks like you had it on (and I don't know in what setting). And well, it's pretty terrible if you have any clue, at all, about what to do.

It's slow witted. In fact I've messed with a few times in various cars. Almost without exception (and in all C5 and C6's) it causes issues. Because I react to a movement before it does. Then it does, and you end up with an overcorrection. In many ways having it all on is better than Comp mode because at least then it comes in sooner and before you can get too messed up which results in a more violent "fix".

Now, putting my instructor hat on. Turn it off, learn to drive the car without it. Otherwise you aren't really driving the car. Last year I had a student with a new M3 take an Evo school with me in GA. I had not driven that model up to that point. His first runs with me in were pretty good. But something wasn't adding up. I was watching his inputs and it sure didn't seem like he was doing the things that would have resulted in the car doing what it was. And then I asked.... and he told me that it was in some mode for performance driving. It was clear something was masking things but it was so good I had no idea to what extent. Now, for the record I think PTM might be that good, but the normal stuff through C6 was not. I digress. Turning the stuff off in that guy's M3 almost immediately resulted in a comedy of errors. Spins, terminal understeer, you name it.

But by the end of that day, he was in command of that car. Not Hans and Franz.

TRSCobra

Thanks for the replies guys. That video was with everything on. Unfortunately the car doesnt get to drive the 200' or so before the run starts, so it's possible that it was never done calibrating. Sounds like AH/TC off is the way to do it, and it's not just my car. Here's a video where I nearly spun with nannies off, but I was able to control the car better and never had to turn around.

Josh67

I'm the guy that was driving the blue C5Z06 out there. It was snowing sideways and sleeting. Pretty sure it was the worse conditions I've ever autocrossed in. I did my first two runs with my AH off then turned it on. Sorry I didn't come say hi, after ******** cones I just wanted to sit in my warm car.

You're welcome to take a ride with me in my car although there are tons of guys out there faster!

TRSCobra

You kicked *** out there on Sunday! I was surprised how well you did in those conditions. Been autocrossing for a while?

I don't blame you for not saying hi, I was in the same situation! This cold and wet weather is getting pretty old...

Bill Dearborn

Your videos come up with errors when I try to play them. It must be you aren't including the complete link to the You Tube video.

I found the problem by looking at your link. When you use the YT tags you only include the video address after the = sign.
https://www.youtube.com/watch?v=d-CK...ature=youtu.be

Bill

TRSCobra

I think I have them fixed. All these replies I'm amazed nobody said anything!

froggy47

Nothing wrong with c6z ah.