Z06Durham

Hello All,

Apologies if this is answered elsewhere or would be better off in another section - tried searching around but couldn't find exactly what I was looking for.

Was curious about the ABS/AH system in the car, and the extent to which it's activated given the scenario. I've had my Z for a few years, and have encountered this a few times now.
Note: My car still has factory sized tires (running PS2's currently), rake was maintained when the car was corner weighted & lowered some on the factory bolts (not on the bump stops), and nothing else that would adversely deviate from the factory setup with regards to the workings of the AH/ABS systems I'm inquiring on. No codes or other symptoms that I've seen either that would indicate a potential problem. I also typically always drive with the car in the "competitive" mode

So this morning I'm merging on the highway, ~60mph, two lanes, sweeping right hand turn, around 90* gradual direction change getting on to the highway from the road I was on, no real elevation changes, mid-corner bumps, etc.

I'm in the left lane [3rd/4th gear, tires fully hooked up/no traction issues, I'm on the throttle some keeping the car balanced through the turn as I'm passing slower drivers on the right building up speed]. Guy in the right lane decides to come over unexpectedly mid-turn, about taking my front end off.

I go to begin modulating the brakes to slow down giving him room (not taking the pedal to the floor or even being overly aggressive) and get ABS chattering/pulsing away under my foot, and little braking ability until the vehicle's direction is straightened back out.

Anyone else come across scenarios like this? My perception was the AH/ABS systems in the car were being overly protective given the steering angle/yaw rate/wheel speeds, and hesitant to allow usage of the brakes mid-turn in this scenario, especially right after accelerating & in a throttle lift-off scenario as more weight was shifted to the nose of the car mid-turn, which would be further magnified by applying the brakes.

I've felt it a few other times when doing ~90*, low speed turns (35-50mph) in 2nd on to an adjacent road, having to lift on the throttle & brake mid-corner due to a vehicle in front suddenly shaving off speed while making the turn much slower than anticipated. Again remedied by straightening the vehicle's direction out or employing some quick counter-steering.

Just curious if any of the forum has experienced a similar effect with mid-corner or even trail braking.

Thanks guys!
Chris

ptindall

No. My car's ABS works properly even with race slicks at loads well beyond factory traction levels. Of course, that's with AH off. On the street, I find the AH gets involved a little sooner than in really needs to but does a great job of correcting yaw. I have never felt excessive ABS egagement in seven years and 50,000 miles of driving, although braking mid corner is obviously a rare event. The problem is either with your perception of events and/or available traction or something wrong with your car, not something inherently wrong with the model. I can't tell which from this side of the internet.

Z06Durham

Thank you for your input & time; it's much appreciated, especially given your experience on slicks & really pushing the car's limits in a track/race setting. I agree the AH does a great job of correcting yaw as well from the few times my butt-meter took the day off & my right foot got a little over-zealous...

Perhaps it is largely my perception? And agree, it's only been in those rare mid-corner, sudden braking scenarios; never encountered it otherwise in all the various spirited driving I've had the pleasure of owning the car for.

Thank you again!

ztheusa

It appears you don't understand how ABS works. It is not possible to stop the car faster than when ABS is in operation.

Z06Durham

Hi - no I understand how ABS works, nor am I implying I could stop the car faster than the ABS.

I'm merely stating that in a mid-corner turn, such as the two I referenced, (my perception?) is that I have less braking capabilities in this car when compared to my other/others I've driven, had anyone else felt the same, and do they feel that the AH/ABS are maybe more "over-active/impeding" vs other cars in some scenarios? That's all.

To maybe rephrase differently: my seat-of-the-pants feeling (perception) based on the higher limits of the car I've pushed it to before vs. those two scenarios involving mid-corner braking, was that I had plenty more grip & available traction, with the car being firmly planted, before I would have wanted (or potentially needed) the AH/(ABS) to step in. Again, as ptindall mentioned, perhaps that was solely my perception of that event.

Thanks