C8 Z51 Brake Cooling Kit Question

[Termie]

So I have a UK C8 Z51, and am planning an alpine road trip and am thinking of getting the brake fluid changed in advance. When looking into this, I also know we have the Z51 brake cooling kit, which I have in a bag that came with the car. Looking at US forums, some people are saying dealers should have installed all of the elements apart from the rear lower control arm cooling ducts at PDI (as these are track only). Should Ian Allan have installed these, but didn't? I'm considering adding them on, given I paid for them, so might as well get some use out of it! Any experiences or definitive guidance would be appreciated. The new UK dealers don't seem to have an answer for me.

Also, if anyone knows if the C8 has a flat beam that doesn't require beam deflectors for driving in Europe, let me know. I'm currently assuming it does, as a modern LED setup that is sold in RHD countries - but again, it doesn't seem straightforward getting this info.

 

[teamzr1]

Dealer should have installed those if customer wanted them on

More info for racing with Z51

Z51 Track Setup Information - Brake Burnishing, Suspension & Alignment Setting
Vehicles without Z51 package should not be used for track events and competitive driving.

High-performance features are intended for use only on closed tracks by experienced and qualified drivers and should not be used on public roads. High-speed driving, aggressive cornering, hard braking, and other high-performance driving can be dangerous.
Improper driver inputs for the conditions may result in loss of control of the vehicle, which could injure or kill you or others. Always drive safely.
Participating in track events or other competitive driving without following the instructions provided may affect the vehicle warranty. See the warranty manual before using the vehicle for racing or other competitive driving.

Be sure to follow all service procedures before driving the vehicle at track events or competitively.

Prior to each track event and again before returning to public roads, tighten the wheel nuts with a torque wrench to the proper torque specification.
Wheel nuts that are improperly or incorrectly tightened can cause the wheels to become loose or come off, resulting in a crash.

If equipped, the front license plate bracket should be removed and replaced with the aero cover for track use.

Engine Sound Management Setting
Do not place the vehicle in Engine Sound Management Stealth mode. Damage could result to exhaust valve actuators.

Engine Oil
If the vehicle is used for track events and competitive driving, the engine may use more oil than it would with normal use. Low oil levels can damage the engine.
Check the oil level often and maintain the proper level. Check the oil level often during track events and competitive driving.

Fuel
Unleaded gasoline, rated at 93 octane or higher, is required. Some high octane fuels contain additives and compounds that may damage the vehicle and void the vehicle warranty.

Dual Clutch Transmission Fluid

The transmission fluid and external filter should be changed after every 24 hours of track usage.
If prompted by the transmission fluid life monitor that remaining fluid life is low, the fluid and external filter should be changed as soon as possible.
Add an additional 2 L (2 qt) of DCT transmission fluid prior to track usage. It is not required to remove the additional 2 L (2 qt) of DCT fluid. Any transmission level set or change should be performed at your dealer.

Brake Fluid

Replace existing brake fluid with a qualified high performance brake fluid from a sealed container. Brake fluid with a dry boiling point >310 °C (590 °F) is qualified. If high performance brake fluid is used, replace it with GM approved brake fluid before driving on public roads.
If high performance brake fluid is in the vehicle and the age of the brake fluid is over a month old or unknown, replace the brake fluid before track events and competitive driving. Do not use silicone or DOT-5 brake fluids. Check the fluid level before each competitive driving event.

Brake Fade Warning Assist

The Brake Fade Warning Assist system monitors the performance of the brake system. If the system detects brake fade, or if the brake fluid is near the boiling point, the driver will be alerted.
The Brake Fade Warning Assist system is designed for use with the factory-installed brake pads or GM-approved replacement pads.
If the brake pads on the vehicle need to be replaced, use GM-approved brake pads.
If this is not done, the brake fade warning system may not function properly.

Stage 1 : The Driver Information Center (DIC) displays a “Reduce Braking to Avoid Overheating” message and brake pedal effort and travel is increased. When the message displays, the driver should decrease brake pedal pressure.

Stage 2 : The Driver Information Center (DIC) displays a “Brakes Overheated Service Now” message that the brake fluid temperature is excessive and is about to boil.
The system increases brake pedal effort and travel, and will also limit vehicle speed. The driver should immediately start a cool down lap if on the track. If this message displays, take the vehicle to be serviced at your dealer.

Brake Burnishing
New brake pads must be burnished before racing or other competitive driving.

Performing the brake burnish procedure on a base brake system can result in brake damage.

The new vehicle break-in period should be completed before performing the brake burnish procedure, otherwise damage may occur to the powertrain/engine.

Brake pedal fade will occur during any track burnish procedure and can cause brake pedal travel and force to increase. This could extend stopping distance until the brakes are fully burnished.
When this procedure is performed as instructed, it will not damage the brakes.

The brake pads will smoke and produce an odor. The braking force and pedal travel may increase. After the procedure, the brake pads may appear white at the rotor contact.
Perform this procedure only on dry pavement, in a safe manner, and in compliance with all local and state ordinances/laws regarding motor vehicle operation.

Brake Burnishing Procedure

This brake burnish procedure should only be run on vehicles with the J55 Z51 factory equipped brake system.
1. Apply the brakes 25 times starting at 100 km/h (60 mph) to 50 km/h (30 mph) while decelerating at 0.4 g. This is a medium brake application.
Drive for at least 1 km (0.6 mi) between applying the brakes. This first step may be skipped if there are more than 320 km (200 mi) on the brake pads.

2. Apply the brakes 25 times starting at 100 km/h (60 mph) to 25 km/h (15 mph) while decelerating at 0.8 g. This is a hard brake application without activating the Antilock Brake System (ABS). Drive for at least 1 km (0.6 mi) between applications.
Depending on conditions, some increase in brake pedal travel and brake pedal force may be experienced.

3. Cool down: Drive at 100 km/h (60 mph) for approximately 15 km (10 mi) without using the brakes.

4. Apply the brakes 25 times from 100 km/h (60 mph) to 50 km/h (30 mph) while decelerating at 0.4 g.
This is a medium brake application. Drive for at least 1 km (0.6 mi) between applications.

As with all high performance brake systems, some amount of brake squeal is normal.

Alternative Closed Course Brake Burnishing Procedure

This brake burnish procedure should only be run on vehicles with the J55 Z51 factory equipped brake system. This procedure should only be run on a track and only on dry pavement.
Brake pedal fade will occur during this track burnish procedure and can cause brake pedal travel and force to increase.
This could extend stopping distance until the brakes are fully burnished.

1. Start track lapping at lower speeds and lower braking efforts for three minutes of driving.
Allow for increased braking distances due to reduced brake output.

2. After Step 1, increase speed and braking effort for the next six minutes of lapping, gradually ending up at 90% effort. Continue to allow for increased braking distance due to reduced brake output.

3. Cool the brakes by lapping with minimal light braking for six minutes.

Brake Cooling Kit

Prior to any track event, high speed driving event, or competitive driving, the following should be completed: Ensure all brake cooling parts are correctly and securely installed.
Inspect for and remove any blockage in the ducts. Inspect and replace any duct that has damage.

 

[teamzr1]

Shock Spring Seat Adjustment

The front shocks, on vehicles without hydraulic front lift and rear shocks, have threaded spring seats that allow adjustment of the preload on the coil springs. The vehicle corner weights can be adjusted for track use. If the vehicle trim height is modified, it should be returned to normal trim height before street use.

The spring seat can be adjusted approximately 20mm (0.8 in) up or down from the nominal position. Each complete turn of the spring seat will change the vehicle height approximately 1.5 mm (0.06 in). When adjusting the seat to the upper limit, lift the dust boot and ensure the seat does not thread off the center support tube (stop adjustment when threads no longer visible).
When adjusting the seat to the lower limit, leave approximately 10mm (0.4 in) of thread visible for the lower lock nut to have full thread engagement.

To adjust the lower spring seat:
1. Raise the vehicle so the tires are completely off the ground.
2. Loosen the lower spring seat lock nut (2).
3. Thread the lower spring seat lock nut (2) downward off of the threads to its resting location on the shoulder of the center support tube.
4. While holding the center support tube holes, turn the spring seat (1) upward to increase spring preload, or downward to decrease spring preload.
5. Thread the lower lock nut (2) back on to the center support tube and torque it against the spring seat (1) to 25Y (18.4 lb ft).

Load Limit

Limit vehicle load to the driver only, with no other cargo. Inflate the front tires to 159 kPa (23 psi) and the rear tires to 165 kPa (24 psi). Drive at a maximum speed of 296 km/h (184 mph). Road Course target hot pressures of 220–240 kPa (32–35 psi). Value will vary based on driving style, track, temperature, and weather conditions.

Wheel Alignment

Using these wheel alignment settings may cause excessive tire wear. Only use these wheel alignment settings for racing or competitive driving. Excessive tire wear is not covered under the vehicle warranty.
The racing and competitive driving wheel alignment settings should be set as described here.

To achieve the track alignment specified settings:
1. The upper control arm to body washers on all four corners will need to be moved from between the body and the control arm and relocated between the head of the bolt and the control arm.
2. Adjust the lower control arm cam bolt position to achieve the following specifications.

Front (per corner)
. Caster: +8.0 degrees
. Camber: -3.0 degrees
. Toe (total): 0.1 degrees toe in

Rear (per corner)
. Caster: 0 degrees
. Camber: -2.5 degrees
. Toe (total): 0.1 degrees toe in
. Thrust Angle: 0 degrees

After track use, reinstall washers between the body and the control arms. Reset to factory alignment settings.

General Information
If reduced performance is experienced during track events or competitive driving, turning off the A/C will help to improve engine performance.

Maintain a mixture of 40% DEX-COOL coolant and 60% clean, drinkable water to optimize engine performance.

 

[Chevrolet]

So I have a UK C8 Z51, and am planning an alpine road trip and am thinking of getting the brake fluid changed in advance. When looking into this, I also know we have the Z51 brake cooling kit, which I have in a bag that came with the car. Looking at US forums, some people are saying dealers should have installed all of the elements apart from the rear lower control arm cooling ducts at PDI (as these are track only). Should Ian Allan have installed these, but didn't? I'm considering adding them on, given I paid for them, so might as well get some use out of it! Any experiences or definitive guidance would be appreciated. The new UK dealers don't seem to have an answer for me.

Also, if anyone knows if the C8 has a flat beam that doesn't require beam deflectors for driving in Europe, let me know. I'm currently assuming it does, as a modern LED setup that is sold in RHD countries - but again, it doesn't seem straightforward getting this info.

Hi Termie, Not having a C8 I don't know. What are the items apart from the cooling ducts? Might be worth enquiring on the C8 Corvette UK Facebook page where C8 track days have been organised/discussed. Or maybe Stuart C. with his new C8 knows the answer? And yes, the headlights are flat beam I think. They can confirm that on the Facebook page too.

C8 Corvette owners UK | Facebook

www.ianallanmotors.co.uk Corvette C8 UK.

www.facebook.com

 

[teamzr1]

If I recall correctly
The brake ducts are two halves and GM suggests using for racing only as in street driving
they could hit like going over curbs, speed bumps, etc

So some owner for street are just taking the bottom half of duct off, leaving top half on

GM
Brake Cooling Ducts

Z51 models include brake cooling parts.
Install the brake cooling deflectors (Fig. 27), except the rear lower control arm brake cooling ducts.

Fig. 27



The rear brake cooling ducts (Fig. 28) that attach to the lower control arms are for track use only and should not be installed during the PDI. Driving the vehicle on the street with the ducts installed may lead to part damage from road debris or poor road conditions.

Fig. 28

 

[teamzr1]

From GM

 

[Termie]

Hi Termie, Not having a C8 I don't know. What are the items apart from the cooling ducts? Might be worth enquiring on the C8 Corvette UK Facebook page where C8 track days have been organised/discussed. Or maybe Stuart C. with his new C8 knows the answer? And yes, the headlights are flat beam I think. They can confirm that on the Facebook page too.

C8 Corvette owners UK | Facebook

www.ianallanmotors.co.uk Corvette C8 UK.

www.facebook.com

Thanks. Teamzr1 has helpfully posted the parts above. I was thinking of adding the top elements front and rear. It is predominantly for street driving, albeit perhaps some fast/heavy braking in a road tour (and the car is also fairly heavy). I'm trying to weigh up the pros and cons. It only came up because I was looking into brake fluid/brake cooling, and then tugged the thread on these parts and saw some dealers are installing the top parts as part of PDI, at least in the US, so it got me wondering. On one hand, I'm not tracking the car really, on the other hand, cool brakes aren't a bad thing and these are OEM Z51 parts that Chevrolet provide...

 

[teamzr1]

The brakes are different for the Z51 than the base models and may be designed to work better in hotter temps than when cold except when racing where lots of brake pedal is used

There's a lot of performance residing within the new zero-copper Non-Asbestos-Organic (NAO) brake pads that are up to speed, so to say, with the new environment regulations.
The NAO pads provide the crucial performance, but also the crucial environmental friendliness that's required nowadays.
The pads on the Z51 are 10 percent larger than the previous generation and feature a new zinc-nickel base coating for more longevity and resistance to corrosion.

More on braking: The standard front rotors measure 12.6x1.18, while the Z51 rotors measure 13.3x1.18.
The standard rear rotors come in at 13.6x1.02, and the Z51 rear rotors measure 13.8x1.06.
Base C8s

Front	Two-piece all-aluminum four-piston caliper (P4.42) Zero-copper Non-Asbestos-Organic (NAO) brake pads (77 cm2) 321 x 30 mm cast-iron disc (12.6 x 1.18 inches)
Rear	Monobloc all-aluminum four-piston caliper (M4.38) Zero-copper Non-Asbestos-Organic (NAO) brake pads (57 cm2) 339 x 26 mm cast-iron disc (13.6 x 1.02 inches) Electronic parking brake (EPB)

Corvette Stingray with Z51 Performance Package​

Front	Monobloc all-aluminum four-piston caliper (M4.42) Low-met brake pads (83 cm2) 337.82 x 29.97mm x cast iron disc (13.3 x 1.18 inches)
Rear	Monobloc all-aluminum four-piston caliper (M4.38) Low-met brake pads (61 cm2) 350 x 27 mm cast-iron disc (13.77 x 1.06 inches) Electronic parking brake (EPB)

 

[Chevrolet]

Thanks. Teamzr1 has helpfully posted the parts above. I was thinking of adding the top elements front and rear. It is predominantly for street driving, albeit perhaps some fast/heavy braking in a road tour (and the car is also fairly heavy). I'm trying to weigh up the pros and cons. It only came up because I was looking into brake fluid/brake cooling, and then tugged the thread on these parts and saw some dealers are installing the top parts as part of PDI, at least in the US, so it got me wondering. On one hand, I'm not tracking the car really, on the other hand, cool brakes aren't a bad thing and these are OEM Z51 parts that Chevrolet provide...

If you ask on the C8 Corvette UK Facebook page, you might get a response from Mick Gilbert in Notts. He is one his 2nd C8 from Ian Allan, and is one of a group of guys there who have bought several IA C8s. He takes his to LeMans.

 

[Chevrolet]

Well it's a "small world" if you live within 10 miles of Ian Allan as I do. There's a very high end car dealer in my town and I speak with the guys who do the car prep. Two weeks ago they told me that James the top mechanic/technician from Ian Allan now works there. So we got James out of the workshop and had a great talk. He's a very nice and helpful young guy. Saw him/had a talk this morning and he is telling that all those items in the back/not fitted by IA are track use items.

 

[Termie]

Well it's a "small world" if you live within 10 miles of Ian Allan as I do. There's a very high end car dealer in my town and I speak with the guys who do the car prep. Two weeks ago they told me that James the top mechanic/technician from Ian Allan now works there. So we got James out of the workshop and had a great talk. He's a very nice and helpful young guy. Saw him/had a talk this morning and he is telling that all those items in the back/not fitted by IA are track use items.

I appreciate you asking. There appears to be PDI sheets that say for Z51 equipped cars, parts of the kit should be installed. See below (first "Exterior" bullet). Apparently some dealers are doing it right, some aren't

 

[Chevrolet]

Confusing? Looks like you are right?

GM’s Response Z51 C8 Brake Duct Installation During PDI - MidEngineCorvetteForum.com

Thanks to MidEngineCorvetteForum members raising this question about the different PDI installs or not occurring on Z51 brake cooling ducts, we learned that not 100% of all dealerships were installing them correctly during the Z51 pre-delivery inspection even though the exact install locations...

www.midenginecorvetteforum.com