I am an instructor with the BMWCCA. We had an autocross on Saturday and I instructed a student with a new C7 with the Z51 package. I have owned a C3 many years ago and have followed the new C7 somewhat. I was disappointed when a DCT was not offered. Instead the brain trust at GM decided a shifting automatic was "just as good".

We did a couple of laps together. The student had previously run Autoclub Speedway in Fontana the week prior. I asked about overheating his auto transmission. The new C7 has a pretty neat display that allows you to view the exact measured temperature of many components including the gearbox. Regrettably, my student reported the gearbox overheated at Autoclub during his track day (300 degrees) requiring him to "shut it down". For a pretend track car, that is most regrettable.

He stated the new Z51 package should have track cooling similar to what the new Z06 will have--- a larger transmission cooler in the right rear area of the car. However, I am most concerned that the Z06 engine will drive the temperatures higher more quickly due to higher torque/performance/use demanded of the transmission.

It is most disappointing that GM did not build a DCT for this car. It is more regrettable that it is not a track car since overheating on a fall day at Autoclub should NEVER happen. Really, how hard is it to provide adequate cooling for the automatic gearbox that you claim is track capable. Well guess what GM, it is NOT a track car. A red flag of note is factory instructions to change the automatic transmission after 24 hours of track use. A good owner would do it anyway but is this an admission of future problems? Who is keeping count of those hours on the track? Hopefully a good owner who is going to be honest on resale.

Before any of you think the manual is the answer, my reply would be why? All other manufacturers are generations ahead on DCT. Go look at the new GT3, the M235i, M4, etc. and you will see manufacturers committed to speed and reliability.

Boo on Chevrolet and GM. FIX IT !

 

Was it a 2014 A6 or a 2015 A8? Sounds like it was an A8 since you mentioned the Z06, but wanted to be sure.

 

We need to know if is an A6 or A8. You get the feeling the A6 in 2014 was a poor compromise, because the A8 was not ready. I will be disappointed if the A8 has overheating problems.

 

I'm not doubting the OP's bona fides, but being on here for five years and having a total of 16 posts makes me wonder if the questions are genuine. I also wonder, considering all the things that people who race keep track of (tire temp, oil temp, track temp, lap times, tire pressure, brake fluid change, oil level increase, etc.), why WOULDN'T a person taking the C7 to the track fail to note the number of hours on auto trans fluid?

If this is merely another call for "DCT" it's a good one for those who want it. If it's a diatribe against an M7, it fails. Overall, I just wonder...

 

Had my A6 Z51 on a 1.7mi track, outside temp low 80s and trans temp after a 20 min session was just over 200, proper cool down between sessions and no problems.

 

Maybe it all depends on how much "go" pedal is used? I don't know...

Not knocking the C7 at all...but...truth is truth...I can only speak from my experience tracking my wife's '14 C7 Z51 auto (A6) - after a few hot laps at our local track (ECR 2.5 mi) the auto gets hot and goes into "limp mode" - meaning that paddle shifting is disabled. This was on the 3rd hot lap with ~80-85 F ambient. It was truly disappointing. The car was great (felt solid/planted in the corners) other than that. To compare/contrast, she had a '12 GS Auto (A6) - it too had overheating issues with the transmission, but it took much longer to get hot...and this is on hotter days, in Texas.

 

The car was a brand new C7 with the 8 speed automatic. The story was the owner's and we talked for quite a while prior to our runs. If you are unfamiliar with Autoclub Speedway you might look up some Youtube videos of the "Roval". The long straight and Nascar 1 turn should cool down most cars before the infield road course.

Yes, I infrequently come to this forum since I am not a current Corvette owner. Based on the report of overheating of the automatic transmission, I won't become one either. Perhaps future production will cure the overheating issues. Until then, I am not going to make the investment into a Z06. There are many ways to ruin an expensive track day but a lack of reliability is in my top two right behind a crash.

There are some amazing features in the car so don't think I didn't like parts of it. The display screen (with track recording), the heads up display, etc. are terrific features. It had excellent grip on the course and was very competitive on the autocross.

So I will occasionally come back to view other posts to see what the real world reports say. My primary concern has always been reliability in Corvettes (my C3 was a disgrace) but time will tell if the automatic has the ability to handle HPDE. So far the only owner I spoke with has told me no.

 

Just maybe the A8 is more adapted for the straight line as opposed to the track course. And it seems like after a couple of laps.....it's done. I am quite sure members appreciate your latest report.

 

My burning question is not whether it was A6 or A8 but whether it was a coupe or Vertte? The coming recall is for the Verttes where the inlet for the cooler is in the rear wheel wells VS on top of the fender.

 

The A8 appears no better than the A6 in this case. Widely reported before..

 

The car was a coupe.

 

Automatics just don't do well on a road course..... all I have seen overheat, American or german. Need a big *** cooler, and its still marginal.

 

I think they are waiting to build the C8 and then put in a proper DCT. The C7 was done after the Mid engine idea was shot down.

 

Until the owner comes here and posts it's hearsay. Statistically one 2nd hand report is meaningless. When more of these get on the road and the track then we will have some definitive answers.

As a side bar, price out those DCT's you mentioned, especially the ones that can handle 1000 Nm of torque then compare them to the $1795 GM charges for the upgrade...... That assumes you can find a DCT that can handle that much torque.

Keep things in perspective and perhaps your rants will have more merit.

 

So let's see, you're an autocross instructor and you won't consider a C7 because of possible auto trans overheating? If you're into racing that seriously why would you even consider an auto trans at all? Buy a manual trans C7 if you're into racing and don't worry about it.

 

You beat me to it

 

Here are some discussions that backs up what you are saying. Note Z06 changes (scoop and larger cooler) will probably not help situation.

https://www.corvetteforum.com/forums...-on-track.html

https://www.corvetteforum.com/forums...n-coolers.html

 

I would consider the automatic because I prefer the electronic paddle shifting. It is quicker and frankly much easier on the track and especially in an autocross. I was interested in the C7 with the automatic because GM offered it in place of the proper shifting gearbox (a DCT). As you may know, some manufacturers of performance sports cars are not offering a pure manual any longer. This is because it is s-l-o-w-e-r than an electronic gearbox.

It remains unproven to me that all auto gearboxes will overheat on the track with a negative tale from one owner. Is that a comprehensive condemnation? No, of course not. Is it a concern for a future or current owner? You bet it is. Will it stop me? Yes.

The Corvette is not the only car with a big torque engine. The slide rule boys in the design shop are supposed to put together something that is going to work properly. If they cheap out on an automatic then the damn thing better handle the job.

 

I couldn't see the paddles-on-the-wheel style (of any mfgr) being preferred for autox.

However, I am concerned that the overheating issues will continue. This 2nd-hand report isn't the first. Hopefully it has an OEM solution. If not, hopefully the aftermarket can get the extra cooling needed.

-bZj

 

the A8 will overheat also....The new Z06 has a bigger trans cooler and fan, also an additional cooler under the car, Do you wonder why ? I have been harping on this issue since i took my Z51 A6 to the track and it lasted 12 min....No fix or aftermarket available yet....Trans lines are in the rear so its almost impossible to add one,,,The older vetts had trans coolers in front so you could add one in front of the radiator.....