63Corvette

I instructed a M7 Z07 student at CoTA yesterday (7/5). I must say that the car is VERY, VERY impressive on track, but my purpose with this thread is simply to note that on a VERY hot day, the car of my student and other Z07 cars on track yesterday ran every session, and my student's car reached 300 degrees oil temperature (much higher than I would recommend) BUT, did not go into shutdown or limp-home mode, nor pull power significantly enough that either he or I could notice it. In addition, I will note that he chose to run Michelin PSS tires, rather than the stickier "Cup II" tires. I was astonished at the grip they provided, as I thought they were Cup tires!. I also run PSS tires on my C5 Z06 (street car) and yesterday I noticed that at CoTA my car had significantly more roll relatively to the student's Z07 car with the same tires. I will let him post suspension setting details and PDR if he chooses.

CGZO6

If his PSS are run flat and yours are not, that would account for some of the roll difference. I noticed a big diff in roll and turn in response when I put non run flats on my 09Z.

Thomasmoto

Yep, me to with my 11 GS.

occar

As long as you're following prescribed guidelines in the manual (change to 15w50 for track then change back after it), I wouldn't be overly concerned with 300 degree temps on the oil. I believe the mark for getting an oil temp warning isn't until 320. Even when/if you hit the warnings, the temperatures were chosen at levels where they're still confident that you aren't going to damage anything. Remember, they picked the thresholds for the warnings at a level where they still feel confident that they can warranty the engine for 5/100k without issue. I am curious though how fast the student was driving. We all know there are varying levels of load people put on cars at these events. Then again, more stress on the car doesn't translate in to faster lap times either always.

Lakeway

I participated in this event with my 2015 Z06/Z07 too. I got an overheating warning during the fourth session when it was about 95 degrees. Oil temp was 300 degrees and I chose to baby it back to the paddock and call it a day.

Given all that I have read on the forum, I was somewhat surprised it didn't overheat sooner. It ran very strong in the earlier sessions with no problems.

The SC2s were great. But, once they're gone I will try to get PSS runflats.

BTW, everything was stock. I'll try a mixture with Water Wetter next time.

63Corvette

My student was quite aggressive!!! For two sessions we followed the same well driven Porsche Turbo S around and, although they had slghtly different techniques and lines because of their different dynamic packages, their lap times were almost identical. I will let my student address the details if he wishes. I solo'd both of my students because both demonstrated excellent competency in their track driving skills.
Also, that is a VERY good point about the run-flats, as I run NON, and I simply did not consider this a factor.

kverges

Agree I'd like to see lap times as indication of how hard car(s) was(were) driven. 98 ambient is brutal on car and driver; a real torture test

emericr

Thanks for sharing. The more posts about this, the obvious it is that the car is sensitive to overheating and depending on the aggressiveness of the driver, the car will overheat.
It's a damn shame and let's hope GM finds an acceptable solution.

blackvetterzo6

300 degree oil and you let him keep driving.....

NineBall

Any COTA lap times? Anything sub-2:40 on street tires is fast at that track. Sub-2:30s if on race tires.

Tony

sam90lx

Shocked if these issues are not corrected on the 2016 which from the looks of it... there not.

05dsom

why does it seem like a crapshoot where some of these cars easily overheat, then we get a bunch of guys whose cars aren't overheating, even in brutally hot conditions?

I guess 300* oil IS overheating, but timing wasn't pulled?
Thats contradicts earlier overheating stories---just very inconsistant experiences from one owner to the next?

kverges

I'll say that I personally know of 991 GT3 on PSC2 at 2:27 and MP4-12C on Trofeo R at 2:25 as pretty quick benchmarks. Both cars stock down to alignment, other than brake fluid and pads (actually GT3 was probably stock pads).

NineBall

Both blazing. I know of one stock Viper TA that went 2:29 on the factory Pirelli tires, but that was a pro driving (Ben Keating).

The thing about COTA is that it costs 2-3 times more than most tracks do, so few people really get to learn the course like their local track. First-timers going sub-2:40 is very good, based on what I've seen.

I've only been on COTA one time, went 2:35 in my stock Viper TA. Had a lot left to learn there!

Tony

baddogz28

So I should be happy with my 2:37.17 in my stock GS on Super Sports yesterday. A buddy of mine that has a radical was like 'that's wayyyy slow.' What a goofball.
For comparison's sake, I saw oil temps about 280 on the LS3.

63Corvette

I saw 286 degrees in my 2004 Z06 (stock except for BBK) then used 6th gear, cooled to 260, got back on it and went to 286 again in 2 or 3 laps and came in. I did not take times (No PDR)

glass slipper

When using 15W50 synthetic oil, there is absolutely nothing wrong with 300°F oil temps. It's also not up to the instructor to make the driver leave the track for 300°F oil temps.

PRE-Z06

Here's a zr1 with minimal mods (seat/harnesses/bushings/alignment/tires) for comparison as well running a 2:25...said he had a better lap that was on pace for a 2:23, but ran into traffic

Snorman

Quikag's ZR1 is on slicks and obviously with a pretty aggressive track alignment. Not really comparable to basically untouched stock-tire cars IMO.
S.

rs06

Maybe the better and more experienced the driver, the less problems with overheating. Aggressive driving style doesn't get the best lap times. Aggressive drivers run out of gas, wear out tires, brakes, blow up engines, transmissions, crash etc etc