The Spark

I was running a new section of track (for me) at MSR Cresson this weekend. It has lots of elevation change and tighter curves.

AH saved me numerous times but on one particular turn it would kick in and totally screw me.

First, I have a 99 coupe and I can not get it into Competitive Driving mode. Yes, I hold the button down.... I believe this was an option in 99 and apparently my car does not have it. The owners manual alludes to Active Handling being an option but I think the Vette has some version built in to save the idiot behind the wheel. AH became standard in 00 or 01.

The turn was about 120* to the left - uphill. I'd brake hard, turn in, then power up the hill. AH would kick in as I hit the apex and kill power to the engine which would totally screw my momentum.

I know it has to do with steering turned hard left, slow speed, and adding power to get up the hill. I tried to straighten the wheels which helped but messed up the line for the next turns. If I had time to work on it I could probably figure out a compromise - but I don't have that kind of access to the track.

I'm not at the point where I can run without AH safely.
Does anyone know about upgrading the AH in the early C5s? Competitive Driving mode should help in this situation - shouldn't it?

TIA

jbauch357

Most likely what you are feeling is traction control kicking in as you add more power than the rears can hold coming out of the corner. Far as I know AH won't pull power, it'll just correct you rotationally if you get in a pickle - add too much power and begin the break the rears loose and TC will kick in reducing power for a couple seconds.

Depending on how hard you want to push you may decide to run with TC off. For lapping days I like to run with TC/AH on, higher speeds and other cars means a mistake can lead to serious car damage - and a half a second during a lapping day won't ruin my fun. On the other hand I run everything off during auto-x, it's far more "violent" than lapping days and being on a controlled course with cones for corners a mistake just means wiping cone marks off...

wtknght1

How do you know??????

Try it with it off...build up your speed slowly and see how it goes. It's a school - learn at whatever pace you're comfortable with.

VetteDrmr

First off, let's determine you've actually got AH on the car. If the disable button on the center console says "Active Handing", then you've got it. If it says "Traction Control", you don't.

It sounds to me like it was simple traction control kicking in. Take a limited-slip diff, hard left turn, enthusiastic throttle application, and voila!; wheel spin and the associated power reduction as traction control takes over.

HTH, and have a good one,
Mike

The Spark

Good points guys - it very well could be TC. It would suddenly reduce power like the engine shut off and then it was like pulling away in 4th instead of 2nd.

It has the TC button on the console - but so did my previous 99.
In the old car, you could hold the button down and get it into CD mode. It had F45 suspension so I don't know if that had anything to do with it.

I'll do some more digging and see what I can find on the 99. I thought all C5s had AH to keep the car pointed straight for those sudden manuevers.

I was doing fine on the "old" section but the turns are not as tight.

I know I need more seat time to build my confidence and learn my car. However, I did move up a run-group for this weekend and was signed off to run solo.

StArrow68

Interesting problems, and don't know '99 but I do know that if you have
the yaw sensor for AH that the software can be upgraded to a later
version. It seems the 2002, maybe 2001, had more ability to slide the
rear than prior versions. I've been told by some that I can't do what I
do with AH on in Comp mode, it gets about a foot rear end slide without
the system using the brakes. Exceed that or do it too fast and the AH
brakes until it gets happy again.
As others note, the engine power cut back is most likely TC and if you
can't get to Comp mode then you are stuck with it or turning the whole
thing off. I understand about not wanting to turn the system off. The
main reason I got the car was I worked for the company that made the
quartz gyro that is the Yaw sensor in the AH system. Figured it would
look pretty dumb if I turned it off and came back to work with a story
about how it hit a wall. That made me look for ways to drive faster and
still keep it on, it can be done, you just have to work on being smoother
than anyone else, not easy. Also if TC is cutting power, then the back
end tires would be starting to spin due to too much power for the grip
available without the system, again calls for being smooth and slow with
throttle application.
As for turning AH off, you will probably be surprised that you won't spin
right away. It does have limits that are lower than what is possible,
however, not a good idea where there are walls. I never turn it off at
Sear Point/Infineon or Laguna Seca but when I get to Reno-Fernley with
lots of desert I run with it off and all the practice at being smooth seems
to pay dividends.
Randy

BTW, AH wasn't offered on the earliest C5's and was then an option for
a couple years before going standard. Yaw sensors were in limited supply
before 2000.

AU N EGL

When ever we get students asking "should I run with AH/TC on, off or comp mode?

We tell them YES.

Run with it on to learn good smooth consistent safe lines, then turn it off to learn how to drive.

The Spark

I have done some research on Corvette Action Center and read in my 99 owners manual.

1. Active Handling was an option on the 99 (guess I was driving better than I thought) AH will apply brake(s) to correct understeer/oversteer but nothing was said about reducing engine power.

2. TCS will apply brake(s) and reduce engine power by closing throttle and retarding timing if wheels spin or are about to spin.

So you guys were right. TCS was kicking in to keep the wheels from spinning.

I think on this corner a little wheel spin would help rotate the backend around to line up for the corner. I wasn't hammering the throttle - if anything I think I'm too timid applying throttle in many turns. With weight shifting to the right I was unloading the left rear tire where it could spin.

I have base suspension and shocks and Z06 swaybars. I'm going to upgrade shocks and springs over the winter. I'm also getting some wider tires (maybe R compound) before next season too.

Thanks for the input.

I wish I could get back on the track to try that turn with TCS off. Unfortunately it will probably be Spring before I get back there.

robvuk

Sounds like you've figured it out now. No AH on your car. You definitely must turn TC off. It's almost impossible to go around a track with TC on.

fhturner

Yep, sounds like you only have Traction Control, and that was kicking in. Active Handling became an option about halfway thru the '98MY, then standard in '01. That was also when the 2nd version became available, which was less obtrusive but still just as effective. One other thing, before '01, you have to be stopped to engage Competitive Driving Mode; '01 and later lets you do it on the fly.

Anyway, if you have Active Handling, the console button will say so, just above it; if you do not, there will be nothing above the button, only the "skidmarks" icon on the button itself. You can also check your RPO codes sticker in the glovebox or left rear cargo cover in the back ('98 and earlier). If you see "JL4" on there, you've got it.

Fred

sothpaw2

Yep. And I drove the car at 1 auto-x for 1 lap with it on and that was all I needed. Off for me at the track unless drag race track. The car is not that different then the C4--learn to drive it.