Rear Brake Cooling Ducts
I always wanted to make functional rear brake cooling. I really liked the cooling setup on a Porsche 962 when I saw one at the races this year (my photo below).
Air coming in from the top down and the flexible hose compressing vertically is very neat.
First step was to get air into the middle of the rotor (as I did in the front brake cooling duct I made earlier). Space was tight. I made a foam pattern and then constructed the duct out of carbon fiber. I will cover the area near the rotor in gold heatproof material to protect it somewhat from high radiant heat from the rotor.
Foam patterns ready for carbon lay up. They do neck down near the rotor as space is tight but the air will accelerate and flow OK.
Carbon dust bolts securely to the aluminium upright in three places.
Next step was to create a fixing point for the top of the hose to marry to the body. The trick is to keep this whole system low enough to fit under the rear clip and allow full suspension travel. An alloy spacer on full suspension travel was used to position the upper mount that is fixed to the chassis.
This alloy plate will allow a pinch weld rubber seal on a body duct to seal correctly when the rear clip is lowered.
Now for the ducts. First foam patterns were constructed. This took a while!
Plastic fitting was the exact point of the allow chassis mounts so a perfect seal could be made. I also made the smaller ducts that channel air to the original cars cooler positions. On my car this will simply cool the extractors a little.
Now to cover in fibre glass, split, remove foam, join again and fill the internal cut line. I wanted perfectly smooth inner surfaces so that when you look down the duct it will be perfect. Nothing looks worse than raw fibre glass.
Finished duct was then fixed into the rear clip.
As you can see below, the duct has to be mounted high on the clip to allow suspension compression. Outer surface of the duct was also smoothed off.
Ducts are symmetrical and don't look too out of place. Not original looking but hell none of the guts of the car does.
Then I also put the gulf rear flares on. What a hell of a job that is, lining them up to be within 1mm side to side took 3 nights!
Edges were feathered on top but without removing too much of the top surface, underneath they were feathered and 4" of glass either side of the join was added along with additional core mat where it had been cut off. Seriously, pay someone to do this if you can it was a PITA! I should have got RCR to do it when they offered!