BRZ Premium custom brake ducting

[ATL BRZ]

I want to talk about taking out the BRZ Premium plastic inserts that the LED's sit on, dremeling out the back of them to allow air flow and installing brake cooling ducts to over to the rotors, like this:



But retaining the factory LED strip in the factory inserts, which of course look like this:


As you can see mine was damaged last night after hitting a huge metal pipe elbow bouncing around on the highway.

Anyone done this before?

[Borden]

I've done this on my old mazda, very effective.

[mashal]

Your brakes don't get that hot to need such an upgrade , if your autox'ng you should upgrade your brakes instead

[RedLeader]

I haven't looked closely enough, but pulling off the front dust shields has just as much, if not more, of an effect on brake cooling than brake ducting does. For a daily driver, this can do more harm than good though, as it can lead to damage to the rotors.

I did this style ducting on my GTI, then took it off because removing the dust shields was easier and more effective.

Are you actually having overheating problems with the stock brakes? usually a high temp fluid change and removing the dust shields will keep the brakes cool enough for most uses. Remember, ducting requires sufficient velocity airflow to the front of the car, unless you install electric fans to keep positive air pressure. If you're not moving forward fast enough, you're not going to get enough extra air over the rotors than normally passes over them while driving.

Just my .02 after having fought this battle with a GTI (3000lb turbo car with single piston front brakes )

[ATL BRZ]

No overheating problems here yet but I do plan on tracking the car once it's ready with enough supporting mods. I figured it was worth experimenting with the damaged insert when I replace it and actually make them functional. My BRZ is my daily so I will probably keep this project on the back burner until years down the road when it's possibly a dedicated track car.

[RedLeader]

Like I said, until you're actually having brake fade or fluid boiling, you don't need to worry about it. And your rotors will only warp if you keep pushing them hard AFTER they overheat and the pedal gets mushy


Sent from...somewhere?

[Racecomp Engineering]

I disagree with the others...brake ducting (when done right!) has a huuuuge effect on rotor temps, much more than just removing the dust shields. We did a lot of testing on our kit for the Impreza and there was a substantial difference. Pads and rotors last much longer as well.

It's important for it to be a well designed kit, with 3 inch hose directing air through the center of the rotor and not just pointed in the general direction of the rotor.

I agree it's not the most convenient thing for a daily driver, but for a car that sees the track often enough it's at the top of the list for us. Removing the hose when driven on the street is a good idea.

- Andrew

[SkullWorks]

I'm a little taken aback by all the people spewing hate for a proper ducting system,

and claiming that removing dust shield is "just as effective"....wow people I mean really?

Obviously there is a huge benefit to adding cooling to the brakes on this car, Having reached the edge of brake fade on the BRz already, considering the brake fluid has never been touched it is still a dry system, it is clear that there needs to be more cooling for the rotors.

Would the car benefit from higher temp fluid? definitely, but that doesn't mean you wont still boil the fluid, it will just take a longer session,,,a smart man will do both....too bad I like my factory fog lights...

[RedLeader]

Originally Posted by SkullWorks

I'm a little taken aback by all the people spewing hate for a proper ducting system,

and claiming that removing dust shield is "just as effective"....wow people I mean really?

Obviously there is a huge benefit to adding cooling to the brakes on this car, Having reached the edge of brake fade on the BRz already, considering the brake fluid has never been touched it is still a dry system, it is clear that there needs to be more cooling for the rotors.

Would the car benefit from higher temp fluid? definitely, but that doesn't mean you wont still boil the fluid, it will just take a longer session,,,a smart man will do both....too bad I like my factory fog lights...

I'm not "claiming" anything, I've done it, and that's what worked. For a daily driver, you're almost never going to overheat your brakes (on the street), so any brake upgrades are purely aesthetic in nature (putting bigger brakes on has a bigger effect on brake cooling than actual stopping distance).

On a pure-race car, dust shields are unnecessary because there's not a lot of dirt, rocks, tire chunks, and other general shit hitting the rotors as on a street car; race cars also aren't driven for 20,000 miles with the brakes and tires being more or less ignored.

And yes, for MOST track-day situations using street cars in a track setting, removing the dust shields can be just as effective, and is remarkably easier, than doing proper brake ducting. Doing this in combination with a higher temp brake fluid and higher performance pads will lead to even better results than brake ducting on its own.

I'm not "spewing hate" either, but if the OP is going to build a brake ducting system in his car "just because" he ought to know that there are easier, cheaper, and just as effective methods of achieving essentially the same results.

Yes, brake ducting, when done properly (reference any DTM/BTCC team) yields great results, but these are professionally designed, and are used on cars with a MUCH higher performance threshold than the average joe in an FRS is EVER going to reach on a track. A side note, if you're overheating your brakes in an autoX event, you've got bigger problems; not autoX run is ever anywhere near long enough or requires enough braking time that your brakes should overheat.

[ATL BRZ]

Originally Posted by Kestrel

if the OP is going to build a brake ducting system in his car "just because"...

I just wanted to throw the idea out there and I'll experiment by dremeling out the back of my damaged plastic insert when I get around to replacing it with a new one. The ducting itself wouldn't be that difficult to install/remove during track day preparation with the wheels off the car anyways. I wouldn't leave the ducting on the car while streeting it.

[SkullWorks]

Originally Posted by Kestrel

I'm not "claiming" anything, I've done it, and that's what worked. For a daily driver, you're almost never going to overheat your brakes (on the street), so any brake upgrades are purely aesthetic in nature (putting bigger brakes on has a bigger effect on brake cooling than actual stopping distance).

On a pure-race car, dust shields are unnecessary because there's not a lot of dirt, rocks, tire chunks, and other general shit hitting the rotors as on a street car; race cars also aren't driven for 20,000 miles with the brakes and tires being more or less ignored.

And yes, for MOST track-day situations using street cars in a track setting, removing the dust shields can be just as effective, and is remarkably easier, than doing proper brake ducting. Doing this in combination with a higher temp brake fluid and higher performance pads will lead to even better results than brake ducting on its own.

I'm not "spewing hate" either, but if the OP is going to build a brake ducting system in his car "just because" he ought to know that there are easier, cheaper, and just as effective methods of achieving essentially the same results.

Yes, brake ducting, when done properly (reference any DTM/BTCC team) yields great results, but these are professionally designed, and are used on cars with a MUCH higher performance threshold than the average joe in an FRS is EVER going to reach on a track. A side note, if you're overheating your brakes in an autoX event, you've got bigger problems; not autoX run is ever anywhere near long enough or requires enough braking time that your brakes should overheat.

don't get it twisted, you are spewing hate,

Most of your pointed remarks aren't even valid for this conversation, (for instance OP never said he was doing this so he could commute without boiling his fluid)

If you think that it takes a team of engineers to design brake ducting and anything less isn't "PROPER" then you live in a fantasy land.

I find far and I mean FAR more tire chunks in my radiator and stuck to my tires after a track day than I do after a canyon run, far more dirt usually too...granted YMMV but it really sounds like you are talking above your pay grade so to speak...

your point about dust shields has been...noted, unless you have something constructive to say now would be a great time to quit...

[Captain Snooze]

.............

Originally Posted by JRitt

Brake ducts on a road car are not a bad idea, you just have to know how to manage them. When a disc is run on the track, the iron expands quite a bit due to heat. When it cools off, it shrinks. The constant heating and cooling, growing and contracting, is what stresses the metal and causes it to crack. Since cooling ducts provide greater airflow and cooling to the discs, they increase the rate of cooling.

Ideally, your discs and pads would maintain a nice steady temperature on the track, without any violent swings upward or downward in temperature. In that situation, the consistency of the brakes would be very good...pads and discs stay at the same temp, and maintain a consistent mu (coefficient of friction). The discs aren't oscillating up and down in temperature, so they aren't as prone to cracking.

Race teams keep a close watch on brake temperatures, and they shoot to eliminate wild swings in temperature. They have a target temperature range based on the pads and overall brake setup they are running for a given track. They can adjust how much cooling air is allowed into the brake ducts, by blocking the duct inlets on the front of the car. If you watch a race at certain tracks, you'll see brake ducts that are partially (or even fully) blocked off.

On a track that is really tough on brakes, you may need as much cooling air as possible, just to keep the brakes in a temperature range where they aren't fading. On a different track however, you may have one very high speed, hard stop, followed by long straights and some low speed stops. In such a case, the brakes would have plenty of time to cool down, even without ducting. If the ducts are wide open, they could introduce so much cool air that the pads don't work as well by the time the car gets back to the hard stop (most race pads don't work great cold...mu varies by temperature), and the discs will get quite a shock going from rather cool (several hundred degrees F) to very hot (possibly 1200F+) during the short time span of that stop. In that case, it would make sense to not use the ducts, in order to keep some heat in the pads and discs during the cooler running portion of the track. That way the upward temp swing isn't as great when you get back to the hard stop, and the pads are already closer to their ideal operating temp.

Also keep in mind that pro race cars have different setups for different tracks. In NASCAR for example, they run heavy duty equipment on a road course like Watkins Glen, whereas on a super speedway that isn't so tough on brakes, they'll run the lightest equipment possible...different calipers, discs, and pads.

For most of the enthusiast, track day, club race guys like us, we don't have the luxury of multiple brake setups. We have one setup, and we have to make it work the best we can. We can use disc paint, which shows the max temp. the discs have reached. Caliper temperature stickers are also available, and you can have a friend check temps with a pyrometer in the hot pits. That is all valuable info to get an understanding of how your brakes are working and the temps they are reaching. Real-time temperature collection is more difficult and expensive.

Then you have to interpret that data based on the tracks you're running and the demands you are placing on the brakes. Are you having any pad fade, are you exceeding the max temps. recommended for the pads you're running, is your pedal getting mushy (fluid fade)??? Then you can decide if you need more or less cooling air, size of duct opening, etc. It's something that takes time and experimentation until you can really dial it in, but every car setup, track, and driver is different. What works for one person in a certain situation, may not be ideal for the next.

[RYU]

Brake ducting done properly has a significant impact. Contrary to what some say here. (Wow, this is the kind of stuff that makes the internet absolutely worthless sometimes)

Here's the order of operations I'd pursue for a weekend track warrior. Let's set aside the discussion on dedicated track builds and/or if you're on pushing more power (FI) or running R-comps.

1. Get some decent sticky street compound tire. Star Specs or the equivalent.
2. Swap out brake fluid to something like ATE Super Blue or the equivalent
3. Swap out brake pads to something like Hawk HP+ or the equivalent. Compounds we can debate for days...
4. Install Steel Braided Brake Lines
5. Inspect the factory dust shield. You may be able to cut vent holes in strategic areas to promote better flow. Remember rotors suck cool air from the center and vent it out like an impeller.
6. Install Brake Duct Cooling done properly.

IF you're still experiencing brake fade or the sort then time to look into BBKs. You're one fast mofo!

With that said, i'd be ALL OVER a kit like this if someone made it for the BRZ Premium. I was actually searching here for one when I stumbled onto this thread.

[GTFrank]

I want the brake cooling. I also want to keep my stock led. If one is not built I will. The hi performance blue is an excellent suggestion.