My C7 Z51 DE Car Conversion
02-28-2015, 01:21 PM
#1
Burning Brakes
Thread Starter
My C7 Z51 DE Car Conversion
I have been going to Road America doing DE's for 14 seasons, last year I bought the C7 Z51 with the idea that it would be my next track car. It was primarily replacing my 1997 M3/4 supercharged car. What I quickly learned with this C7, is that it is a monster on the track, great chasis, differential, grip etc. In short fantastic but what I also found out were it's shortcomings.
First issue - Brakes, when I looked at the stock C7 Z51 brakes, on the surface they looked like they would be great, maybe some cooling and they would always be adequate. Wrong, I had catastrophic brake failures my first time on the track. They are not meant for repeated stops at high speed circuits like Road America.
Solution - Wilwood 4 wheel brake kit with the new Aero 6 and Aero 4 calipers, along with race pads and Titanium backing plates.
TCE to the rescue here.
Second Issue - Temps/Heat while at the track I heard of numerous people having issues with their electronic valves failing, I also saw water and oil temps on the verge of being right at the edge. In addition transmission and dif temps are right on the edge.
Solution - DeWitts Radiator - twice the thickness of stock, this should help with oil and water temps, 170 degree thermostat, Ceramic coated headers 2000 degree black inside 1400 degree ceramacote on the outside, wrapped the exhaust with Lava Wrap where it comes into proximity with the rear dip and transmission (this worked fantastic), Z06 rear air ducts for the tranny and differential cooler. Radiator hose where it goes near the CAI will be wrapped with a lava sleeve to protect against ambient temps.
Third Issue - The car runs out of steam at 6k rpm and several tracks a shift can be eliminated if the car would pull to 7k rpm. Overall HP is not suited to high reving race tracks the car needs more shifts to keep it in its power band.
Solution - Staying NA with ported and polished head from Texas Speed, VVT II Cam Kit to keep streetability. Long Tube American Racing Headers, Cold Air Intake from AFE, AFI balancer to reduce potential engine vibration and harmonics from new power set up. UDP catch can for dry sump applications (my motor was dry when taken apart but this is good insurance), C7-R Racing Timing chain.
Fourth Issue - Grip stock tires are expensive to run on the track and though very good they are not up to the limits on this car.
Solution - TSW Interlagos 18/19 wheels with Ferrari challenge Pirelli Scrubs. If there is a better race tire out there I don't know what it is.
All in I paid 53k for my C7 Z51 LT1 and I have about $10k dollars so far in improvements. For $63k I am expecting to have a car that can do the following
My Goals
1. Pull as hard as a C6 Z06, and possible hang with a heat soaked C7 Z06.
2. Stop consistently and not suffer catastrophic brake failure
3. Remain cool at the track and consistently lap with out heat soak
4. Provide grip equal to the power levels in the car
5. Not overstress the stock motor and provide a repeatable platform
The work will be done by March 20th, I am expecting to get around 530 whp, excellent stopping power, great heat management, and a reliable track car that should run with the best.
First issue - Brakes, when I looked at the stock C7 Z51 brakes, on the surface they looked like they would be great, maybe some cooling and they would always be adequate. Wrong, I had catastrophic brake failures my first time on the track. They are not meant for repeated stops at high speed circuits like Road America.
Solution - Wilwood 4 wheel brake kit with the new Aero 6 and Aero 4 calipers, along with race pads and Titanium backing plates.
TCE to the rescue here.
Second Issue - Temps/Heat while at the track I heard of numerous people having issues with their electronic valves failing, I also saw water and oil temps on the verge of being right at the edge. In addition transmission and dif temps are right on the edge.
Solution - DeWitts Radiator - twice the thickness of stock, this should help with oil and water temps, 170 degree thermostat, Ceramic coated headers 2000 degree black inside 1400 degree ceramacote on the outside, wrapped the exhaust with Lava Wrap where it comes into proximity with the rear dip and transmission (this worked fantastic), Z06 rear air ducts for the tranny and differential cooler. Radiator hose where it goes near the CAI will be wrapped with a lava sleeve to protect against ambient temps.
Third Issue - The car runs out of steam at 6k rpm and several tracks a shift can be eliminated if the car would pull to 7k rpm. Overall HP is not suited to high reving race tracks the car needs more shifts to keep it in its power band.
Solution - Staying NA with ported and polished head from Texas Speed, VVT II Cam Kit to keep streetability. Long Tube American Racing Headers, Cold Air Intake from AFE, AFI balancer to reduce potential engine vibration and harmonics from new power set up. UDP catch can for dry sump applications (my motor was dry when taken apart but this is good insurance), C7-R Racing Timing chain.
Fourth Issue - Grip stock tires are expensive to run on the track and though very good they are not up to the limits on this car.
Solution - TSW Interlagos 18/19 wheels with Ferrari challenge Pirelli Scrubs. If there is a better race tire out there I don't know what it is.
All in I paid 53k for my C7 Z51 LT1 and I have about $10k dollars so far in improvements. For $63k I am expecting to have a car that can do the following
My Goals
1. Pull as hard as a C6 Z06, and possible hang with a heat soaked C7 Z06.
2. Stop consistently and not suffer catastrophic brake failure
3. Remain cool at the track and consistently lap with out heat soak
4. Provide grip equal to the power levels in the car
5. Not overstress the stock motor and provide a repeatable platform
The work will be done by March 20th, I am expecting to get around 530 whp, excellent stopping power, great heat management, and a reliable track car that should run with the best.
03-01-2015, 07:26 AM
#5
Safety Car
The brake issue is interesting. You're getting totally different results than GM testing got. Braking technique maybe?
It'll be interesting to see what the race car people discover. If the car is having all these problems on a track day just imagine if people start racing it.
Richard Newton
It'll be interesting to see what the race car people discover. If the car is having all these problems on a track day just imagine if people start racing it.
Richard Newton
03-01-2015, 08:20 AM
#6
Burning Brakes
Thread Starter
The brake issue is interesting. You're getting totally different results than GM testing got. Braking technique maybe?
It'll be interesting to see what the race car people discover. If the car is having all these problems on a track day just imagine if people start racing it.
Richard Newton
It'll be interesting to see what the race car people discover. If the car is having all these problems on a track day just imagine if people start racing it.
Richard Newton
By comparison I could go out in my M3 with a 4 wheel Stoptech kit use the same braking techniques and never have an issue. Bottom line is the stock rotors are not large enough or designed to shed heat like a true BBK is.
Also the stock brakes are not really good racing brakes they have rubber boots and are very heavy. The calipers from Wilwood alone are 4 lbs lighter than stock.
03-01-2015, 08:22 AM
#7
Burning Brakes
Thread Starter
I think it is going to look very nice when done, and sound awesome.
03-01-2015, 10:15 PM
#9
Burning Brakes
Thread Starter
03-08-2015, 12:36 PM
#12
Burning Brakes
Thread Starter
With that I think I will be at C7 Z06 HP levels, or very close.
But it should be sustained power that doesn't drop with heat soaked Supercharged Motor.
03-08-2015, 01:20 PM
#13
Gasoline Addict
I was really hoping to put on the MSD Intake but it isn't coming out until April 22nd. That will probably get added as well.
With that I think I will be at C7 Z06 HP levels, or very close.
But it should be sustained power that doesn't drop with heat soaked Supercharged Motor.
With that I think I will be at C7 Z06 HP levels, or very close.
But it should be sustained power that doesn't drop with heat soaked Supercharged Motor.
03-08-2015, 03:21 PM
#16
Drifting
03-08-2015, 04:40 PM
#17
Melting Slicks
03-09-2015, 05:09 PM
#19
Drifting
The biggest issue with the brakes is the rotors, but even after I replaced the fronts with Racing Brake two piece rotors I was still getting fade.
By comparison I could go out in my M3 with a 4 wheel Stoptech kit use the same braking techniques and never have an issue. Bottom line is the stock rotors are not large enough or designed to shed heat like a true BBK is.
Also the stock brakes are not really good racing brakes they have rubber boots and are very heavy. The calipers from Wilwood alone are 4 lbs lighter than stock.
By comparison I could go out in my M3 with a 4 wheel Stoptech kit use the same braking techniques and never have an issue. Bottom line is the stock rotors are not large enough or designed to shed heat like a true BBK is.
Also the stock brakes are not really good racing brakes they have rubber boots and are very heavy. The calipers from Wilwood alone are 4 lbs lighter than stock.
03-09-2015, 07:17 PM
#20
Racer
