R33 Rear Brake Ducting

[JDSracing]

Who here runs brake air ducting onto the rear brakes of an R33 (GTST in my case)?

My question is mainly how have you done it and where have you sourced the air from?

My last trackday was ended early by my rear passenger side caliper falling apart due to excessive heat, so I need to run some sort of ducting to try to cool them down.

I have 400R side skirts (from Jetspeed) on my car, with holes just behind the door. Now I assume this is for brake ducting but does anyone know for sure whether air flows into these? (Not around? They are Jetspeed knock-offs)

If air does flow into there, I guess that would be the best place to run it from because the air is going to still be cool and not carrying heat from the engine. (Alternative being running ducts from under the car, which I assume would grab a lot of heat off the bottom of the engine / exhaust).

Attached is a picture of the car + side skirts for reference

[redevil]

yeah i'd suggest cutting holes in the body behind them and then knocking up some aluminium guard type things to direct the air towards the wheels rather then just inside the body

[Ant97GTR]

Interesting....How do you know the caliper fell apart due to exessive heat? The only reason I ask is the the rear brakes do sweet FA in relation to the fronts and would be surprised if that was the cause.

No one I know uses rear brake ducts even on some very powerful GTR's in the state but I'd say your best course of action would be to run some simple tubing underneath the car directing air flow onto the rear brakes.

[Roy]

Yeh gut feel is you had another problem that caused the high temperature. Possibly a seized piston? What exactly do you mean by fell apart?

[JDSracing]

Alright, fair enough, I guessed at it being because of heat. I think I was on my 7th hard lap and the pedal let go all of a sudden and I shot off into the paddock.

By fell apart I mean (and this is what I'm guessing happened),

The pad locking mechanism broke (that was the part I assumed was from heat)

The pads came out one at a time,

The piston seal broke

Brake fluid started running onto the disc and caught fire

And I made it back into the pits with a nice flame coming off my disc (quite hard to put out too).

[Roy]

Shit! Not good. Who changed the pads, and when were they lat inspected? Im guessing the bobby pin or whatever its called was not installed into the pins that go through the caliper and pads allowing the pins to move...which they seemed to have done

[JDSracing]

The pads i did myself a few days beforehand, put new Ferodo DS2500s on all four corners. The pins were definitely put back, as I remember inspecting them at the time and thinking they should have been a lot thicker.

Those pins I think are a bad design, but it was no better or worse than the other pin which held up. (For reference, they wouldn't be thicker than your average paper clip).

It's all fixed up now, I just want to make sure a similiar thing doesn't happen when I go back again (because it is mighty hard getting a car without a brake pedal home when it's over 3 hours a way and you don't have a tow car or trailer).

[tacker]

The pads i did myself a few days beforehand, put new Ferodo DS2500s on all four corners. The pins were definitely put back, as I remember inspecting them at the time and thinking they should have been a lot thicker.

Those pins I think are a bad design, but it was no better or worse than the other pin which held up. (For reference, they wouldn't be thicker than your average paper clip).

It's all fixed up now, I just want to make sure a similiar thing doesn't happen when I go back again (because it is mighty hard getting a car without a brake pedal home when it's over 3 hours a way and you don't have a tow car or trailer).

Simple piping for rear brake cooling

[51jay]

I'd suggest you use split pins as retainers instead of the flimsy looking spring thing

[evil_weevil]

Tacker - nice set up - can you get that pipe from any hardware store?

how much approx?

[JDSracing]

I'd suggest you use split pins as retainers instead of the flimsy looking spring thing

I'm looking into a better way to lock the pads in at the moment, individual split pins may be the answer, but the holes on the "bolts" that they get put through are very small - I'll post up a picture of what I've done with it when it's sorted out.

[Neil]

The Gibson GTR's used ducts similar to what tacker posted but they were left simply either side of the tail shaft and straight.

As Roy and the boy's have said,,,you have made a mistake on the install. Consider yourself a lucky little vegemite,,,It could have been a lot worse.

As for those stupid feeble clips,,,I have often thought about changing them and my prefered method would to tie-wire them together (like you would do to sump plugs ect),,,not too tight though as you don't want to start pulling the pins together and making them jamb up against the pads. My sports sedan has been running this method for ages and Duncan's GTR will be getting this as well as Dan's drift car.

Neil.