[Kmeleon]

Originally Posted by Osbornsm

I have an interesting thought regarding lap times vs driver inputs...

Context
I HPDE my SS 1LE in "Track - Sport 1" and my times are mid pack for an SS on OEM tires.

Q: What Track mode do you most commonly use?

I know the car can be faster in more advanced modes, but I tried "Sport 2" for a lap or two... and once active handling is off my talent seems to run out. Counter-steering every other corner.
"Race" is even more slippery than the previous, so no thanks there.

I figure Chevy has tc, so why work without a net? No prizes in HPDE.

A video would be worth a million words so we can see how you're driving the car.

If the car is sliding as much as you say in the higher modes you're over driving the car. Quite frankly I run sport 1 with a brand new track that I'm not familiar with, as I get familiar I step up to Sport 2 and when I feel I've mastered and being held back a bit by the nannies I go to race and I usually pick up time with each mode. For example when I went from sport 2 ro race earlier this summer at Pocono as I began to master that course I immediately went 1.5 seconds faster from the better turn in, rotation, etc. The nannies were really holding me back once I really started to wring out that last little bit of speed.

[Alpha1BC]

Originally Posted by VR Baron

I have been doing temp/psi checks during this years events. This is autocross mind you and not overly scientific. Just to see how temps per the dic were doing vs tire psi and if I can depend on the car readout. Tire psi from the sensors are to slow in autocross and are always at least 2 psi lower then checking with a accurate tire gauge, and that’s full warm after three laps.Same for street driving, sensors seem to be just slow.As to temps they “appear” to at least coincide to external tire temps by temp gun(I know not the best way to check temps). My dic temp read “normal”(roughly 50-115 degrees range from what I have read )by the end of the third lap temps read warm and tire temps I get 130-140 degree readings with temp gun. So at least temp readout seems to work if it is needed for ptm function. But psi readout sure isn’t keeping up, so hopefully it isn’t a big factor, for autocross anyway. And that’s with stock tires for street, but 19” wheels and 305/30 re71s for track

Yeah, I would expect the ranges to be relatively consistent using that method, but the readings update even a little worse that the tire pressure does compared to the actual surface temp of the tire. It takes time for the air to warm up and then more time for the sensor to measure it. If you took a trace of actual tire tread/carcass temp and compared it to the air temp reading there'd be some pretty significant lag in the air temp.

That's simply speculation on my part for one reason why it wouldn't be used, though. I've checked with the engineer I know that directly works on PTM, measured tire temp doesn't have any impact to PTM slip thresholds.

[VR Baron]

Originally Posted by Alpha1BC

Yeah, I would expect the ranges to be relatively consistent using that method, but the readings update even a little worse that the tire pressure does compared to the actual surface temp of the tire. It takes time for the air to warm up and then more time for the sensor to measure it. If you took a trace of actual tire tread/carcass temp and compared it to the air temp reading there'd be some pretty significant lag in the air temp.

That's simply speculation on my part for one reason why it wouldn't be used, though. I've checked with the engineer I know that directly works on PTM, measured tire temp doesn't have any impact to PTM slip thresholds.

Cool on the last part. Good to know, thanks. I won’t waste anymore time checking it.

[khcoaching]

The SC3 a surprisingly good tire on the track. In my experience, it does get pretty greasy at higher pressures. I shoot for 32-33 hot and it stays pretty darn stable during sessions.

Ken

[Osbornsm]

Originally Posted by Kmeleon

A video would be worth a million words so we can see how you're driving the car.

If the car is sliding as much as you say in the higher modes you're over driving the car. Quite frankly I run sport 1 with a brand new track that I'm not familiar with, as I get familiar I step up to Sport 2 and when I feel I've mastered and being held back a bit by the nannies I go to race and I usually pick up time with each mode. For example when I went from sport 2 ro race earlier this summer at Pocono as I began to master that course I immediately went 1.5 seconds faster from the better turn in, rotation, etc. The nannies were really holding me back once I really started to wring out that last little bit of speed.

Here is a video hot lap of my fav track. Driving inputs are always welcome, especially as they relate to traction control modes.

[cre8fun]

Doesn't this also want you to be running on the OEM-supplied tires as well? I mean, wouldn't different tires likely have slightly different slip vs psi and/or slip vs temperature profiles?


Norm[/QUOTE]

yes in fact he said one of his gripes was that legal would not allow the ability for the driver to tell the PTM whether they were running SC3 or SC3r's. he said they had the data for both tires and they know some SS 1LE owners will run SC3Rs at the track, so he wanted to be able to let the driver dial in the correct program but legal said no.

[khcoaching]

Quick watch of the video -

IMO - Your turn in points are too late making your turn in rate too quick which has you with too much wheel angle too soon. The wheel should (ideally) move in a linear rate to and from the slowest point of the corner.

Ken