Brake Cooling Kit For GT3..??

[009]

Just curious to know what is the best solution to brake cooling on GT3’s, ( especially the fronts ), as it seams that even with fast road use the heat dissipation through the wheels after parking is excessive!!
Dose anyone do a kit ?

[Merritt]

If you have a MkI, yes there are aftermarket kits available. Give JZ Machtech a call:

www.jzmachtech.com/shells/

MKIIs don't usually suffer with brake cooling problems as the brake/air ducts are more than adequate especially for the road.

Cheers

Steve

[maximu5]

Carnewal has some kits. I installed the brake ducts and it reduced temperature of my front discs by some 100 degrees C

[gfreeman]

maximu5 said:

Carnewal has some kits. I installed the brake ducts and it reduced temperature of my front discs by some 100 degrees C

The motorsport ducts are cheaper from Parr or an OPC - around £70+vat each

[DanH]

gfreeman said:

maximu5 said:

Carnewal has some kits. I installed the brake ducts and it reduced temperature of my front discs by some 100 degrees C

The motorsport ducts are cheaper from Parr or an OPC - around £70+vat each

Think the carnewal kit feeds air from the front valance though. Motorsport ducts are even lower than the RS ducts, which aren't exactly immune to damage!

[maximu5]

On the website of Carnewal the picture of the ducts makes it look like they take air from the front valence, whereas in fact they scoop air below the car and then channel it through ducts to the discs/calipers. Because the duct scoop is narrower and closer to the weels, I have found it is relatively immune to grounding than a simple scoop. Takes a while to install though (says my mechanic...)

[DanH]

maximu5 said:

On the website of Carnewal the picture of the ducts makes it look like they take air from the front valence, whereas in fact they scoop air below the car and then channel it through ducts to the discs/calipers. Because the duct scoop is narrower and closer to the weels, I have found it is relatively immune to grounding than a simple scoop. Takes a while to install though (says my mechanic...)

Interesting. Wonder if there is a pic about of them mounted. Must be a simple DIY?

[slippydiff]

Dan, I had these fitted to my car by JZM. To work correctly they require the arch liner be removed (and thus the front bumper as well ?) and then cut to allow the airflow exiting the radiators to exhaust into the area in front of the wheel.
It seems to have reduced brake temps to the point whereby a quick run down an A road (or a motorway) without touching the brakes results in a very dead brake pedal because temps have dropped so much. (I'm using standard pads)
I'm still not convinced of the durability under duress of the new standard discs I've fitted and thus I may upgrade to the Mk2 six pot callipers and 365mm Alcon floating discs you have fitted.

On undulating roads the ducts deck out constantly (Steve at JZM decribed them as sacrificial !)

Edited by slippydiff on Sunday 2nd July 10:56

Edited by slippydiff on Sunday 2nd July 10:57

[maximu5]

I would agree that the ducts reduce front disc temperature by so much (in my case from well over 400 degrees C on a cool track day to just under 300 degrees C on a cool day) that it only makes sense to fit them for track use.

[DanH]

slippydiff said:

Dan, I had these fitted to my car by JZM. To work correctly they require the arch liner be removed (and thus the front bumper as well ?) and then cut to allow the airflow exiting the radiators to exhaust into the area in front of the wheel.
It seems to have reduced brake temps to the point whereby a quick run down an A road (or a motorway) without touching the brakes results in a very dead brake pedal because temps have dropped so much. (I'm using standard pads)
I'm still not convinced of the durability under duress of the new standard discs I've fitted and thus I may upgrade to the Mk2 six pot callipers and 365mm Alcon floating discs you have fitted.

On undulating roads the ducts deck out constantly (Steve at JZM decribed them as sacrificial !)

Edited by slippydiff on Sunday 2nd July 10:56

Edited by slippydiff on Sunday 2nd July 10:57

Yeah my standard ducts are held together with gaffer tape

Does the mk1 not come with dangly ducts OEM?

[slippydiff]

maximu5 said:

I would agree that the ducts reduce front disc temperature by so much (in my case from well over 400 degrees C on a cool track day to just under 300 degrees C on a cool day) that it only makes sense to fit them for track use.

Max, I found the standard discs started to warp without the MK2 /Motorsport ducts/deflectors fitted (even under hard use on the road) as a result I was getting bad steering wheel shake when braking from speed.

Dan, IIIRC the std MK1 deflectors are tiny in comparison with the MK2 Motorsport parts.
Steve at JZM reckons the totally standard MK1 set up only allows 15-20% of the airflow of the uprated parts !

Edited by slippydiff on Sunday 2nd July 14:22

[maximu5]

interesting

[johnfm]

slippydiff said:

maximu5 said:

I would agree that the ducts reduce front disc temperature by so much (in my case from well over 400 degrees C on a cool track day to just under 300 degrees C on a cool day) that it only makes sense to fit them for track use.

Max, I found the standard discs started to warp without the MK2 /Motorsport ducts/deflectors fitted (even under hard use on the road) as a result I was getting bad steering wheel shake when braking from speed.

Dan, IIIRC the std MK1 deflectors are tiny in comparison with the MK2 Motorsport parts.
Steve at JZM reckons the totally standard MK1 set up only allows 15-20% of the airflow of the uprated parts !

Edited by slippydiff on Sunday 2nd July 14:22

Disks don't warp - there virtually solid 32mm think bits of steel. Your brake judder is from pad material deposits on the disk - did you bed the disks and pads in?

[slippydiff]

John, I mentioned to Steve at JZM about the steering wheel shudder under heavy braking, I asked him about the pad transfer.
He replied "pad transfer" isn't an issue with road pads.
As regards the bedding in, I took it gently for the first 200 miles or so after fitting the new pads and discs.
Steve Mc said the discs are specially ground to allow rapid bedding in of the pad to the disc.

Steering wheel shudder under braking is a"pet hate" for me (I find it very disconcerting !) JZM gave me the impression it was a problem with all Mk1 GT3's (due to the poor cooling of the discs) and that the only way to cure it for good was to go for the floating Alco discs with the MK2 six pot calipers.

I beleive you have the larger discs fitted to your car ? do you get any steering wheel shake at all ?
My everyday car weighs a lot more than the GT3, has single pot sliding calipers, regularly attains theree figure speeds (on a race track obviously) and the brakes never complain or cause the steering wheel to shudder !

[DanH]

Low ride height adds to brake cooling problems, as do splitters etc that direct air away from the underneath of the car. I've definitely imprinted on disks using road pads, but other reasons for shudder are imbalances in disks (e.g poor quality rotors may not be as uniform as you'd expect), poor mounting & etc. Pretty sure you can warp disks by not cooling them down properly and just parking. You then have the area covered by the pad cooling at a different rate to the rest of the disk...

FWIW I have the alcon setup with RS29s and they are excellent. No judder etc. The pads are race pads though, so a bit dead when cold (a couple of corners sorts that though). They squeal a bit with road use, but not much can be done about that, as low speed braking strips off the transfer layer that bedding in has applied. I'd definitely recommend the setup.

[johnfm]

slippydiff said:

John, I mentioned to Steve at JZM about the steering wheel shudder under heavy braking, I asked him about the pad transfer.
He replied "pad transfer" isn't an issue with road pads.
As regards the bedding in, I took it gently for the first 200 miles or so after fitting the new pads and discs.
Steve Mc said the discs are specially ground to allow rapid bedding in of the pad to the disc.

Steering wheel shudder under braking is a"pet hate" for me (I find it very disconcerting !) JZM gave me the impression it was a problem with all Mk1 GT3's (due to the poor cooling of the discs) and that the only way to cure it for good was to go for the floating Alco discs with the MK2 six pot calipers.

I beleive you have the larger discs fitted to your car ? do you get any steering wheel shake at all ?
My everyday car weighs a lot more than the GT3, has single pot sliding calipers, regularly attains theree figure speeds (on a race track obviously) and the brakes never complain or cause the steering wheel to shudder !

I have the MK2 brakes on the front. No judder at all. Now I've said that, I'll probably get some!!