Race 2 will not prevent wheelspin on corner exit. As mentioned previously, you can powerslide and drift in that mode so in that case it is 'working' by not intervening. If you want heavy intervention then use Sport.

 

That’s what I thought, but I don’t understand the post saying he unwound the wheel because power was being cut?

 

Yeah we discussed way back at post 5 as far as the original post. I agree 100 percent trying to mat the throttle is not the correct way to use PTM and the manual is misleading at best suggesting it. The car will absolutely get sideways in ptm sport and up.
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I just don't see any purposeful unwinding. It was a half second of minor steering adjustment. He was going in too hot and I agree he should have lifted. He shouldn't have been looking for additional power but who knows.

Interestingly had he been in a lower ptm mode it may have straightened him out better where he wasn't countersteering enough.

Imo that video shows just how beneficial it could have been to use more ptm intervention as there was zero intervention as he spun.

We've all dropped a wheel. Even in a car with no nannies at all.

We don't expect it to result in a tire failure and had a safety feature been engaged it may very well have given him that extra time he needed to put in that counter steer he was too late with.

 

Jay explains it pretty well in the other thread. I guess I should clarify since 'everything you say can and will be used against you' in this thread. PTM mayintervene if there is extreme steering angle (among a bunch of other parameters) involved. However, in my experience, if you're taking a reasonable line and just on the throttle too quickly and kick the rear end out some, it's not going to stop that. I believe that is what OP is experiencing.

 

My point is if you program yourself to mat the gas and let the computer do the work for you then it may not always work out how you want. Dropped a wheel many of times, bent a rim once though fortunately never had a tire let go. You do this sport enough it’s not a matter of if, but when. I personally like to teach car control to mitigate risk and not rely on the engineers programming within an unknown set of parameters, though a man has to know his limitations and exercise self control in this sport. To me running w/o nannie’s actually serves to instill that fear/consequence that helps to keep me in check.

 

For sure and I can appreciate that. It's a good conversation that doesn't necessarily have a right or wrong side imo.

 

Yea, I’m a bit confused because the video has a description of what happened after the crash clip, saying the driver unwound the wheel to get more power off traction control, and the youtube channel itself seems very much affiliated with the driver, Marko, given it has a lap record video of Marko in the Z, and several other videos of the car.

I don’t have ptm so I don’t know whether it flashes any lights when it is functioning, so I’ll have to defer to ptm/esc/tc experts of this chassis. The only time I’ve had any of the tc/esc lights flash on track is actually with ESC and TC fully off, ironically, due to the aforementioned transmission protection notification.

Maybe placebo effect, but it did seem to not be pulling much until that point when I watched it.

Is there actually a TC light that flashes on the dash during ptm use? I thought that there was only an ESC light that flashes when ESC intervention occurs. Forgive me if there is a TC light that flashes for TC work by ptm, or if the same light flashes for either TC or ESC intervention (i.e. the light I referred to as “ESC” light).

 

Jay (steelankles) reviewed Marko's PDR data - I assume in Pi Toolbox - and is giving the narration at the end of the video based on his findings. It is not apparent in the video that PTM is intervening so it must be in the raw data. In the prior version of PDR (C7) you would get an indicator in the video overlay when PTM was intervening. However, in the new C8 PDR based on reviewing my own data it seems you only get the following indicator when TC is intervening. According to the manual both TC and ESC are disabled in Race but there is obviously still intervention at times. My assumption is since the core TC and ESC are disabled there is no visual indicator, which I think is a big miss. Again, assumption (I know...) but I poked through a few of my PDR recordings in Race and I can't find any visual cues. One thing also to note FWIW is the PTM intervention is much more obvious on the C7 because the ignition cut sounds like a 2-step brraaappppp. In the C8 it is more transparent; TQ maybe more managed via the throttlebody closing vs an ignition cut.



Cold, damp track with nannies fully torqued:

 

After talking to a buddy who works for GM to get a better understanding, in Race 2 the ESC is off meaning you can have yaw though the TC can still engage based on wheelspin. Which isn’t how I thought it worked exactly initially and makes sense now that he was having wheelspin which limited power despite His steering angle. His shorter than OE rear tire would cause it to engage quicker as well, so once you’re at a certain level of driving I feel the traction control engaging can be an inhibitor as I initially thought causing you to not to be able to position the car around the track as you may want.

 

 

I think it’s more noticeable in the C7Z06/ZR1 because it’s supercharged and it has to pull more torque vs the C8 being NA. I could feel it intervening in the student’s C7GS I drove on track with P4S tires though it wasn’t audible like in the videos you see of many leaning on it. To me the nannies help a novice advance quickly to a faster pace because of the sense of confidence, but that doesn’t mean they necessarily are learning car control. That’s why I recommend novices go autocross with everything off fwiw and to stick with stock/inferior tires to not hide mistakes as it’ll pay off in the long run of building better habits.

 

There it is. That's the telemetry and it shows exactly what the video shows. He simply went in too hot and not quite on the line he should have been on. He dropped the wheel. He doesn't come off throttle until he drops the wheel. Way wrong time to do that. He then didn't get it counter steered fast enough.

There was no significant steering unwind nor any significant power decrease he was working"against" prior to the off. He was going too hot.

A more aggressive ptm mode would have potentially helped avoid this.

 

When getting used to the car. If you turn off the nannies and max the power. The dash board should light up and ask. Do you really think you're Mario Andretti?. Place thumb print here to acknowledge all safety systems turned off

 

https://www.roadandtrack.com/news/a4...-powered-cars/

 

Wait, what? That is a completely different video of a C7 is it not??

Again, the guy narrating the C8Z vid I posted appears to be closely affiliated with the driver of the C8Z, so I don’t know why he would make things up. It is possible though of course. Wish we could get the data on the C8Z with throttle and timing vs accelerator position.

 

If it is that's a big oops lol. My bad. . I thought he was in the c7 as a reference lap but was comparing to the c8 drivers data. Yeah would be great to see the c8 data, doh

 

It’s pretty obvious to me that PTM in the C8, ZL1 Camaro and C8 ZO6 all react differently even though they are in the same modes.

 

Wow, nice F up... Notice that once he breaks the rear loose by getting the left rear wheel off the track, he doesn't even THINK about braking hard until he is nearly into the wall.

Looking at some of his other videos at VIR, he has a tendency to use every last centimeter of curbs, and this one wasn't so forgiving.

 

Please do not rely on the driver aids vs. learning how to drive the car properly.

As I've told my mid engine students, picture the throttle and accelerator as attached with a rope and as you unwind feed in throttle clearing the apex. Won't need the computer to do it for you.

 

For those saying he doesn’t come off the throttle prior to dropping the tire, you should watch the video more closely. Marko is a very good driver. The mistake he made was trying to eek out an extra tenth or two by briefly unwinding the wheel because he didn’t think the car was giving him full power. This caused him to push wide. He realized he was pushing and he definitely does feather the throttle, and in fact the car upshifts. He almost made it, and the reason he doesn’t is because the FIS curbing suddenly stops and becomes narrower. He was probably right on the edge, and had some tire overhanging, but when the curbing suddenly got narrower he abruptly went off, and the tire went flat. At that point there was no saving it. If he had realized he was going to off, it would of been better to drive straight off, because there is plenty of runoff there, but it’s easy to say that after the fact, and he was very close to making it. I don’t fault him for this, it’s a judgement call and I respect his judgment. We all decide how much risk to take in this pursuit. I also think his line was a bit wide, but there are many lines through hog pen. You don’t have to closely apex it, and you can be wot prior to the throttle.
I also just want to comment on the PTM modes. I personally drive my C8 in sport 1 (sport) on the track. I don’t find it intrusive at all, in contrast to dry, which is very intrusive. Even in sport you can lose the back if you’re too aggressive with the throttle coming out of a turn. In modes higher than sport 1 or sport you lose the esc or yaw control, but still retain some traction control. Some of the fastest drivers I know drive in sport. One did a 1.56 at VIR in a stock C7 Z06. In speaking to these drivers, they say the difference between sport and race or race2 in terms of lap times is very small, and you are giving up a safety cushion, although I wonder if any car intervention can save you from a snap oversteer as occurred here. The other issue with all the modes, is that they do nothing to prevent you from pushing wide, as happened here. Again, we all do what works for us and our personal driving styles and risk tolerance and there is no right or wrong.