froggy47

I recently put on some rear tires that are .7 inch shorter than the fronts. I got them free & just use them to drive the car on short local trips.

I know I'll get active handling every so often as the program thinks the rears are spinning up.

I like to keep the nannys on around town just in case.

I was wondering if I just put it in comp mode, if that'll quiet nanny down & still leave me a margin of protection?

What do you think.

Don't post stuff about how it'll crash and burn because the wrong size tires are on it, just specifically if comp mode will keep the computer more "happy" with the wrong tire height stagger.

VetteDrmr

Actually, to be specific, the traction control will engage, AH still works OK, at least on my '00 FRC. I always run in Competition mode when I run on the street in your configuration (which I did many times with my autox tires).

Tastes great, and less filling!

Have a good one,
Mike

froggy47

Thanks, I wasn't quite sure whether it was tc or ah. The msg (I think) said ah but I'll have to verify that next time I drive it.

Bill Dearborn

AH won't activate since it uses the steering sensor, yaw and lateral G sensors to determine when to activate. It uses the wheel speed sensors to determine how much force is needed to slow the wheel where it chooses to apply the brake. If the wheel speed signal is to fast or to slow for a given condition it may apply the wrong correction factor. That would result in the car not responding correctly and the system going crazy trying to get the correct brake application.

Bill

VetteDrmr

I didn't think AH used wheel speed sensors, just to see what the driver is telling the car to do turning-wise (steering angle, speedo), compares that to yaw rate sensor, and applies the brake to the given corner if that's out of limits.

Bottom line: I've never had AH activate when I was running smaller diameter rear tires when driving on the street. Never had a problem with ABS, either. Just TC, which makes sense.

Have a good one,
Mike

froggy47

I drove it tonight easy, to the gym & got nothing. I think it come on when I floor it, will give a go tomorrow.

froggy47

I got on it & can make the msg come up anytime.

"Traction sys active" is what it says.

I think it cuts fuel briefly but hard to say, I'll play with it more tonight & try to see if it pulls timing, cuts fuel, applies brakes (don't think its brakes.)

It must be tied in with an accelerometer (g force must be present before system kicks in?) since I get zero nanny when driven easy.

froggy47

Tried again,

There is no braking, the gas pedal just seems to go a bit dead, I could still accel a bit but seems like 1/2 power until the msg goes out.

Interesting feature, that I have never experienced.

Thanks all.

VetteDrmr

And when you go to Comp mode the loss of power shouldn't happen (i.e. she drives normally).

Have a good one,
Mike

WSIRFan

My '01 Z did the same thing Sunday at the Mojave Mile. Two runs with all systems go, then less throttle in third gear and I think the message was "Active Handling", but I was busy. Pushed the button and acceleration returned. After that, I disabled it on the 2-3 shift (didn't want to deal with traction issues in 1st & 2nd w/530WHP) and all was well. It ran 168.9mph in the mile.

froggy47

Correct, I get no interference in comp mode.

froggy47

Yes, sounds like the same.

Mine is because I have short rear tires tricking the sys into thinking there is wheel spin, yours was probably actual wheel spin (depending on your tire size)