C7 Z06 Cooling System Development

 

c7z_premod

We were approached by a customer to solve the overheating problems plaguing his 2015 Corvette Z06 track car.  Even with an aftermarket radiator and upgraded transmission & differential coolers, it was still unable to complete more than 6 laps at Circuit of the Americas.  In September of 2015, in 100°F weather, water temperatures were north of 260°F, and oil temps were almost 300°F.

We set a goal of a full summer session at Circuit of the Americas without overheating, while developing a solution that could be sold to the public along the way.

As of July 26th, 2016, the car is able to run a full 30-minute session without slowing down.  The full cooling package is in production and is expected to be up for sale in late Summer 2016.

Below are our test results for our development program.  Unless otherwise noted, all sessions were run on the 1.7 mile road course at the Motorsport Ranch in a counter-clockwise direction.

Test 1- June 30th, 2016

Major Changes- Side-mounted intercooler radiators, redesigned intercooler coolant system, and  auxiliary radiator in front of main radiator.

Results

Total run time (non-consecutive) 13 minutes, 55 seconds
Average Lap Time 1:37.8
Ambient Air Temp 97°F
Engine Coolant Max 229°F
Supercharger Coolant Max 226°F

Notes: E-Diff and Active Handling issues prevented laps run at “full speed.”

Test 2- July 1st, 2016

Major Changes- Changed coolant routing to flow through main radiator first, then auxiliary radiator.

Results

Total run time (non-consecutive) 14 minutes, 17 seconds
Average Lap Time 1:25.8
Ambient Air Temp 92°F
Engine Coolant Max 250°F
Supercharger Coolant Max 219°F
Oil Temp Max 302°F
Trans Temp Max 210°F

Notes: Better heat transfer through radiators, found anomaly with intercooler pump behavior.

Test 3- July 2nd, 2016, 1st Session

Major Changes- Laid auxiliary radiator down horizontally in front of main radiator.

Results

Total run time (non-consecutive) 11:24.7
Average Lap Time 1:25.6
Ambient Air Temp 92°F
Engine Coolant Max 232°F
Supercharger Coolant Max 227°F
Oil Temp Max 302°F
Trans Temp Max 237°F

Notes: Improved engine coolant temperatures, but transmission temps are starting to climb.

Test 4- July 2nd, 2016, 2nd Session

Major Changes- Added oil cooler in front bumper.

Results

Total run time (non-consecutive) 17:33.6
Average Lap Time 1:27.8
Ambient Air Temp 98°F
Engine Coolant Max 237°F
Supercharger Coolant Max 227°F
Oil Temp Max 302°F
Trans Temp Max 275°F

Notes: Oil temps still high, still having intercooler pump problems.

Test 5- July 7th, 2016, 1st Session

Major Changes- Opened up bumper cutouts further, offset auxiliary radiator and transmission cooler to allow more airflow to trans cooler.

Results

Total run time (non-consecutive) 19:14.2
Average Lap Time 1:27.5
Ambient Air Temp 89°F
Engine Coolant Max 221°F
Supercharger Coolant Max 230°F
Oil Temp Max 280°F
Trans Temp Max 230°F

Notes: Transmission temps improved, but intercooler pump problems caused early end to session.