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-   -   brake cooling? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/brake-cooling-42624/)

B430 01-03-02 11:45 AM

brake cooling?
 
the guy i bought my car from (86 GXL) said not to put foglights in the openings in the front because they are for brake cooling and without them the calipers get too hot, is this true and what if i put those little round lights? would it be ok then?

NCsublime 01-03-02 12:10 PM

1. He has no idea what he is talking about.

2. My 91' NA FC has STOCK rectangular fog lights.

3. I've never had any brake cooling problems.

4. There are ducts for brake cooling behind the fog lights (you can see them if you get under the car and look around), but air can still flow around the lights as they don't completely fill the openings.

5. The actual ducts that are for brake cooling are VERY small. The opening is about the size of a quarter or maybe a little larger. There would be no reason for such a large gap (ie. the fog light opening in the bumper) if it was primarily for brake cooling.

6. The round lights are fine. Use what YOU want to.


-Derek

Gene 01-03-02 04:22 PM

yeah the stock brake cooling isn't very good. Lots of japanese tuner magazines show how to use clothes dryer air hose to rig useful brake ducts, I've seen it like 5 times on fc's in those magazines...

Cwaters 01-03-02 04:57 PM


Originally posted by NCsublime
1. He has no idea what he is talking about.

2. My 91' NA FC has STOCK rectangular fog lights.


The 91 FC had a different nose, ya know....


3. I've never had any brake cooling problems.


I would think cooling needs would depend on driving habits.


4. There are ducts for brake cooling behind the fog lights (you can see them if you get under the car and look around), but air can still flow around the lights as they don't completely fill the openings.


But not as much air and not as freely , right?


5. The actual ducts that are for brake cooling are VERY small. The opening is about the size of a quarter or maybe a little larger. There would be no reason for such a large gap (ie. the fog light opening in the bumper) if it was primarily for brake cooling.

The ducts in my 86 GXL's nose are MUCH bigger than a quarter.....

6. The round lights are fine. Use what YOU want to.

I suspect that the little round lights wouldn't cause a big problem. The bit rectangle ones, I wouldn't try.

-Derek


Cory

Icemark 01-03-02 05:34 PM

On the 86 I would agree with that you should avoid placing the fog lights in the ducts.

The series 4 cars have a different flow through than the series 5 cars like NCsublime's. Even though the fog light is partial covering the duct on the series 5 cars the duct size and area is considerably bigger.

I have had brake cooling issues like glazed front pads on my old 87 sport, so I wouldn't block the opening on a series 4 car in anyway.

Better to use a smaller fog/driving light in one panel on each side of the front grill, since the blocked panels on a series 4 car can be opened up for increased flow.

SpeedRacer 01-03-02 06:40 PM

If you are having problems with brake cooling after putting in fog lights, try slotted and or cross-drilled rotors, or bigger rotors. Upgrade to 4-pistion calipers(if you don't already have them) try different brands of brake pads, or add some sort of ducting to better cool your brakes.

No7Yet 01-03-02 10:53 PM


Originally posted by SpeedRacer
If you are having problems with brake cooling after putting in fog lights, try slotted and or cross-drilled rotors, or bigger rotors. Upgrade to 4-pistion calipers(if you don't already have them) try different brands of brake pads, or add some sort of ducting to better cool your brakes.
Uh, no.

When you drill or slot your rotors, you decrease their mass, and therefore their heat dissipation capability. If you're having brake cooling issues, go back to stock solid rotors. If you're having pad float issues, and you're running the best pads you can find, then try cast-"drilled" rotors. Never buy rotors that were once stock, and then drilled out later - that reduces their strength.

More on-topic, I've compared the 89+ and 86-88 brake ducts, and found them to be roughly equivalent in size on the brake side, and slightly larger in the 89+s on the nose side. Certainly larger than a quarter :rolleyes: I personally would not block my brake ducts with foglights, but unless you're really cooking your brakes it's not much of an issue. Keep in mind that the 87-88 TII wheels are not very brake-friendly, so if it's an S4 TII we're talking here, either forget running foglights, or think of upgrading your rims.

Brandon

B430 01-04-02 12:37 AM

i think i'll make brake ducts and go with the little fogs for now, in the summer i'll get some good rims that let more air in. it's really cold now and i don't race the car (esp. in winter) so brake cooling shouldn't be a problem now, i just wanted to know if he was BSing me.

Silkworm 01-04-02 01:13 AM

What the hell are you guys doing on the street getting brakes that hot?!!! I honestly think those ducts are totally useless, they don't come anywhere near the brakes. You should be just fine putting lights in those openings.

PaulC

Juan 01-04-02 02:41 AM


Originally posted by Silkworm
What the hell are you guys doing on the street getting brakes that hot?!!! I honestly think those ducts are totally useless, they don't come anywhere near the brakes. You should be just fine putting lights in those openings.

PaulC

I agree. I took those things off and put some aftermarket fogs in there. I havent noticed any weird brake problems yet and Im using auto parts brake pads.

http://www.imagestation.com/picture/...5.jpg.orig.jpg

http://www.imagestation.com/picture/...6.jpg.orig.jpg

Icemark 01-04-02 11:17 AM


Originally posted by Silkworm
What the hell are you guys doing on the street getting brakes that hot?!!! I honestly think those ducts are totally useless, they don't come anywhere near the brakes. You should be just fine putting lights in those openings.

PaulC

Three words: Mountain bonzi runs... where real men race/drive.:cool:

The vents on my old sport and my GTU actually spray air (and water when it rains) right on my front brakes. Try it yourself with a water hose sometime (after the brakes have cooled of course).

SureShot 01-04-02 11:57 AM

These are wired as daytime running lights.

EProdRx7 01-04-02 12:15 PM

silkworm I hope you are running the ducts on your S car. You will need them. If you are interested I have made Carbon backing plates paterened after the Mazda comp ones for my car. Let me know if you are interested in a set.
JW

Silkworm 01-04-02 12:40 PM

Yes, I do plan to run ducts. How much for the CF ductwork, I'm interested, but I'm working on the cheap at this point, and my buddy and I can weld aluminum, so I'll probably make it at this point

PaulC

Juan 01-05-02 02:16 AM


Originally posted by EProdRx7
silkworm I hope you are running the ducts on your S car. You will need them. If you are interested I have made Carbon backing plates paterened after the Mazda comp ones for my car. Let me know if you are interested in a set.
JW


do you have any pictures of them?


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