village idiot

Bill Dearborn

We recently had a forum member set a very fast lap at VIR with an A8 and the car didn't over heat while he was running. M7s just don't over heat at all. I don't know what happened at Spring Mountain but I know what happened at a lot of other tracks since there are videos posted on YouTube and pictures of the associated vehicle health data stats posted on the forum with the linked videos. It isn't just a few it is lots of them. Considering most of us get 3 to 4 videos per day at least 10 days per year and have collecting them over the last 2 years there are a lot. Enough that it isn't anecdotal data anymore. Over heating has become anecdotal info since we really don't see the videos and vehicle health statistics to back up the claim.

Bill

SouthernSon

like I said, "fantastic". When I see it firsthand, then I will believe it.

SocalC5Z

Let's see...we have no less than 4 class action lawsuits, numerous threads on this forum and others re C7Z overheating and reduced power on the track, and a major Corvette aftermarket manufacturer has developed a kit to deal with the problem...seems to validate an issue. Don't forget GM has been making running changes to address this issue as well.

I've personally been on two tracks in SoCal (WSIR and Autoclub Speedway) where the subject vehicle has been driven hard enough to go into overheat and brought in short of a full session.

Not bashing GM or denying that track use requires upgrades, just questioning why anyone here would want to sugar coat the problem like it didn't exist.

village idiot

SouthernSon

I might add one more thought to the discussion: Can a pro driver purposely overheat the car in a few laps? You betcha! Can a pro driver keep everything nice and cool on a hot day doing some very fast laps? that too - you betcha! Anyone with only limited track experience understands this.

High horsepower, lots of torque requires driving discipline. To make any vehicle absolutely, 100% immune to any overheating conditions under any circumstances would require a lot more than any manufacturer is going to release to the public with a warranty - (heavy, cumbersome, fuel mileage eating, expensive, warranty prohibitive item).

village idiot

No one is asking it to run 24hrs of LeMans; this thing can't make it through a few laps of HPDE.

Poor-sha

Stock 2015 with the GMPP secondary radiator that was included in all 2017+ cars.

village idiot

Poor-sha

95F ambient.

Peak fluid temps that session:

Oil: 276F
Coolant: 226F
Trains: 276F

SouthernSon

Appreciate the actual data! That's what I have witnessed as well. Unfortunately, hearsay and rumors get repeated way too many times. BTW, nice driving. I'll bet you could get a little more speed out of the back straight into the brake markers with more aggressive brake pads.

quick04Z06

The lawyer stuff is silliness and simply not accurate; Porsche makes factory race cars that it sells all over the world, including here in the USA. Lawyers do not stop them. Their street GT3 and GT2 RS are pretty racy and sold here.

Porsche's street cars, at least a few of them, do pretty well on track, but like all street cars, it makes sense to baby them some on the track if they are stock.

GM could make a serious, track-worthy Corvette, and I believe they have done so with the ZR1 (go check out bear.127 on Instagram--he is driving his new ZR1 mostly stock at tracks all over, and running it hard). But the Z costs quite a bit more than a base Z06 and much of that extra cost goes to making it better on track.

Also, we know Chevy builds every Corvette to be able to be a reasonably comfortable grocery-getter. They could ditch this principal and offer a true "track pack", although its sales would be limited. Most people drive Corvettes on the street; but, I would like to see Chevy over a serious track pack that needs no upgrades for HPDE duty with a good driver (even if not warranted) as well as offer real customer race cars (not street legal) like Porsche does. This is a large untapped market for Chevy, if handled correctly.

village idiot

Poor-sha

I've gone faster since, I like to keep that video around though just because I commented on the heat right before I went out. My best was a 1:57.5 but that was last November and the ambient was around 70F.

I don't know what to tell you other than I've been tracking a 2015 Z06 and then a 2017 Z06 since the beginning of 2015 and never had it overheat. My 2015 had 62 days and 120+ track hours on it when I sold it. My 2017 had another 19 track days on it.

My point isn't that nobody has had their car overheat on track but rather that is isn't as endemic as some would like to say. I agree that the autos have more issues, I also know that some folks are tracking their cars well in to 100+ ambients, and finally, I agree that slower tracks where people are spending more time in 2nd gear without any big straights to aid cooling are having more issues.

I have lots of data on both of my cars and even some data on other cars (ZL1, GS, a Z06 with the LG cooling stuff on it) at VIR and despite the hype I'm not seeing big differences in fluid temps between them.

Here are the max fluid temps for Koan's session at VIR where he ran a 2:01.6 in his GS.

Coolant: 219
Oil: 278
Trans: 231

SouthernSon

That's scootin' pretty good!

village idiot

I agree that with the 2017 aux radiator and manual, it's not nearly as bad as pre-2017 and/or manual. It's still an issue and not a good situation.


I'm not sure how your Z06 and a GS run the same engine oil temp though. Z06 has a lot more power, a blower and intercooler. 260s is about where my engine oil sits on warmer days. I haven't really had a change to get into it on hot days, but it's going to be 106 when I go out this weekend.

Poor-sha

At 106F I'd be in the RV taking a nap. I think the reason is because the GS was using 2nd gear a lot more and kept the revs higher trying to extract the power. You don't need to keep the C7Z pinned at redline all the time, with such a broad torque curve it has plenty of grunt to come off the corners.