Looking for brief summary of Z06 overheating issue
 

I know there's a massive sticky thread that would answer all my questions if I had the time to read through it all. I'd appreciate a brief reply to my question including correcting any misconceptions I may have had in describing the issue.

Here are some of the things I've read:

• The Z06 should have never been advertised as a track capable car as it generate more heat than it's capable of cooling.
• There is a class action lawsuit against Chevrolet.
• The overheating will ONLY affect owners that track their cars (especially in warmer climates).
• If you overheat, you have to pull over and let the engine cool down
• There are a handful of alternate solutions to improve the cooling, but it will void your warranty.

Question: If I was to purchase a 2019 Z06, will it have the exact same cooling issue as say a 2015? Or has GM made marginal improvements to the Z06 cooling over the last few years?

Ok, here is my take on it.

• The Z06 is very track capable, under the right conditions. The Manual (post 2017) has been run very hard at the track with minimal issues. The auto still has issues when hot at a road course, this is helped greatly by manually short shifting.
• There are several.
• In normal street driving (even spirited) you will not have an issue with a properly operating Z06 (there have been some issues with air in the intercooler loop, easily fixed).
• no, the car will enter a reduced power mode but you can keep driving, in fact it is better to as you have more air flow.
• True.

If you purchase a 2019 you will take advantage of the improvements made in 2017, especially on a manual car.

Good luck, some great resources here are Poorsha and Bill, both have a lot of track time.

There are some things that aren't true in the statements you have listed.
GM advertised the car as the most track capable Corvette ever. And the car fills that bill. You pretty much don't have to do anything. With the C6Z you had to add brakes almost from day one. With the C5 Z06 you had to add oil, diff and transmission coolers along with brakes.

I have a 2015 Z06 M7 and track it all the time with no over heating issues. You can find plenty of posts stating that on this forum from people like me. I can't say exactly what it would do if I hadn't added the GMPP Secondary Radiator before my first track event with the car in April of 2016. With the Secondary Radiator my coolant temps have remained in the mid 220s and my oil temps have remained in the mid 270s even when I am driving in ambient temps of 90 to 95 degrees. By the way coolant over heat isn't reached until coolant reaches 262 degrees and oil over heat isn't reached until oil temps hit 320 degrees.

In 2017 GM made the Secondary Radiator standard on all M7 Z06s and changed the supercharge to get better charge cooling for cylinders number 7 and 8. With my 2015 I was getting an intermittent high rpm misfire at cylinder number 8 that was causing my top speeds to drop off to some degree. That seems to have been resolved by making sure my intercooler system has almost all air removed from it. The 2017 supercharger change was designed to improve intake cooling to both rear cylinders and reduce the chance of misfires.

I am originally from upstate NY and used to run at the Glen up to 20 track days per year. Since I got the 2015 I have been back there twice in the summer to run the car. In 2016 the misfire was bothering the car so my top speeds were limited to some degree. A few times I only hit 137 to 140 mph at the end of the back straight which is about what my 97 C5 would hit. When the car was not misfiring it would hit right around 150 to 152. This was in high 80s to low 90s temps. In 2017 I went back in June and set my personal best lap time of a 2:05:81 in high 80s low 90s temps. I have never seen limp home mode on my car and have never had to park it while it cooled down. I personally haven't met anybody at the track with an LT4 who has had to do that.

You don't need alternate solutions if you purchase a 2017 or newer M7 Z06 and you don't need alternate solutions if you purchase a 2015/2016 M7 Z06 and add the Secondary Radiator.

You may get posts from some people who say they know so and so had this problem or say they had the problem and they might have. However, as I said before I haven't been at a track event over the last 2.5 years where another M7 Z06 owner has run into over heating problems.

Here is what the data from my personal best run at the Glen looked like:
https://cimg4.ibsrv.net/gimg/www.cor...3f68145939.jpg
https://cimg5.ibsrv.net/gimg/www.cor...5f8c760bb1.jpg
Here is the You Tube Video showing the Session. My fastest lap is on Lap 14 which comes around the 41 minute mark. The ambient temp on June 9th, 2017 at 2:46 PM was in the high 80s.

This a video taken by my car being driven by me and the data is from that session. Does it look like a car that isn't track capable? I don't think so. I have a ton of PDR videos with data taken at several tracks showing the car performing without over heating. Poor-Sha has more from both his 2015 Z06 and 2017 Z06.

Bill

OK, thanks guys....that's exactly what I was looking for.

The M7 Z06's with the aux radiator don't overheat, the A8's do. What if the transcooler for the A8 was relocated and the M7 aux radiator installed in it's place? Something similar to the D3 oil cooler setup would work if it was the same btu rating as the stock transcooler. Has anyone tried that yet?

Drove manual Z06 at the driving school for 2 days in 110° Nevada weather and not once did it overheat. Didn't even come close. There were a few auto Z06's in the class. I should have asked if they had any issues, but none were brought up by them afterwards.