The case for A8 @ Track (Road Course)?
Instructor
Joined: Jul 2017
Posts: 222
Likes: 43
Probably a stupid question, but does the overheating issue affect all A8 cars? Or just the supercharged version. Mine is the stingray 460hp version and very, very much enjoy tracking my Hellcat...Hhoping to track the Vette in the spring.
Melting Slicks
Joined: Aug 2000
Posts: 3,436
Likes: 977
From: Overland Park KS
Remember that it's not the transmission per se that is causing the overheating on track in the A8 Z06; in fact temperatures within the transmission itself are very well controlled by the secondary transmission cooler in the nose of the car, and it's running way cooler than the M7 numbers some owners are reporting.
The issue is the ECU/TCU programming that GM chose to use whereby in 'D' mode the transmission stays in the lowest gear possible which then of course means the engine is running at close to red-line and hence producing the greatest amount of heat. It is the inadequate engine oil and water cooling systems that then place the car in 'limp' mode and ruin track days for owners.
This can be mitigated to a large extent by never driving in 'D' mode on the track; (and frankly why the hell would you want to anyway as the TC transmission whilst excellent isn't a Porsche PDK-S), and short shifting around 5500 rpm. You can run for 20-25 minutes this way on most tracks during most ambient temps, but it is frustrating as hell tbh. M7 owners don't have the secondary transmission cooler in the nose but rather a secondary water radiator, so even though they are revving as high as an A8 in 'D' mode, the increased heat sink is able to deal with the excess heat from the engine in most circumstances.
The car simply should never have been produced with three heat exchangers stacked together in the nose of the car with limited airflow to begin with, and at the very least, a true stand-alone engine oil cooler should have been standard.
Bish
The issue is the ECU/TCU programming that GM chose to use whereby in 'D' mode the transmission stays in the lowest gear possible which then of course means the engine is running at close to red-line and hence producing the greatest amount of heat. It is the inadequate engine oil and water cooling systems that then place the car in 'limp' mode and ruin track days for owners.
This can be mitigated to a large extent by never driving in 'D' mode on the track; (and frankly why the hell would you want to anyway as the TC transmission whilst excellent isn't a Porsche PDK-S), and short shifting around 5500 rpm. You can run for 20-25 minutes this way on most tracks during most ambient temps, but it is frustrating as hell tbh. M7 owners don't have the secondary transmission cooler in the nose but rather a secondary water radiator, so even though they are revving as high as an A8 in 'D' mode, the increased heat sink is able to deal with the excess heat from the engine in most circumstances.
The car simply should never have been produced with three heat exchangers stacked together in the nose of the car with limited airflow to begin with, and at the very least, a true stand-alone engine oil cooler should have been standard.
Bish
Last edited by thebishman; Nov 15, 2017 at 12:38 PM.
Thread Starter
Burning Brakes
Joined: Jan 2013
Posts: 796
Likes: 213
From: East of Baltimore MD
I never intended to drive my car in 'D' mode on track. I fully intend to shift via paddles which hopefully give me at least 20 minutes of track time each session.
There has to be something we can all do to help with the car temps. Considering the vast majority of these models sold are A8's, one has to wonder about why GM just dropped the ball with A8 owners.
The Z06 whilst amazing in every other area (Don't get wrong, I love this car!), the bad press surrounding this model makes for sour apples.
There is nothing better than GM coming off the gate with fixes for these cars retroactively .
There has to be something we can all do to help with the car temps. Considering the vast majority of these models sold are A8's, one has to wonder about why GM just dropped the ball with A8 owners.
The Z06 whilst amazing in every other area (Don't get wrong, I love this car!), the bad press surrounding this model makes for sour apples.
There is nothing better than GM coming off the gate with fixes for these cars retroactively .
Intermediate
Joined: Oct 2016
Posts: 37
Likes: 8
I have stock 2015 A8 non Z07 that I've tracked at COTA in Austin a number of times -- steel brakes, stock pads, only upgrade is a track alignment, SRF brake fluid, and I swapped MPSSs for Cup 2s after I wore out the MPSS. I drive this car to work, and take my daughter to school, in the same set up I track it in. I have not once overheated it. Oil and water temps definitely get elevated, but you can manage it (manual shift short of redline). I also wouldn't recommend tracking in 90+ degree heat.
My times are typically in the mid 2:20s in the advanced solo group. Typically one of the faster cars, with only well driven GT2s/3s being consistently competitve with me. And often they are running R compounds or slicks to my Cup 2s.
Where else you going to get a car you can comfortably daily drive, esp. at this price, then drive to the track -- with your comfortable street legal setup -- and set times like this? And I'm sure a better driver would be even faster!
see: https://youtu.be/EzP7RTdkX9o
My times are typically in the mid 2:20s in the advanced solo group. Typically one of the faster cars, with only well driven GT2s/3s being consistently competitve with me. And often they are running R compounds or slicks to my Cup 2s.
Where else you going to get a car you can comfortably daily drive, esp. at this price, then drive to the track -- with your comfortable street legal setup -- and set times like this? And I'm sure a better driver would be even faster!
see: https://youtu.be/EzP7RTdkX9o
