Brake cooling

[dradernh]

Originally Posted by Malt

There's no way I'm at your level of driving ability but assuming R-Comps with slightly lower than stock weight and say.... 300 whp. Is it worth stepping up to the endurance set over the sprint.

In all honesty the sprint setup is most likely WELL above what I need in terms of my ability as a driver, I'd just hate to shaft myself over a $500 difference in price between the endurance set and sprint set. I haven't bought wheels yet so I'm still able to go either way, but the last thing I want to do is respend money when I could of just bought something overkill that would have suited my needs.

Is there anything detrimental about the endurance set as opposed to the sprint set that I should be aware of?

How are you going to be using the car?

[rice_classic]

Originally Posted by CSG Mike

FTFY.

Ducting brings the equilibrium point down, but also comes at the cost of larger temperature swings. This application of ducting is a band-aid for a braking system that is just too small.

To me this suggests that professional race cars don't have brakes that are big enough since so many run ducting... But that's not why I'm here.

I need to the see the math or the data to flesh out how lowering the equilibrium = increases temperature spikes. Do you have a resource for this Mike? My experience from the hundreds of cars that run ducting here in the Pacific Northwest is that brake ducting, even on cars with massive rotors, is always good and you can never get enough of it. Rotors/pads/fluid all last substantially longer as a result. I will add that in the PacNW, we don't have any tracks with excessively long straights that we would ever run on in very cold weather. So what you speak of simply may not be a concern in this neck of the woods.

But then again, maybe all cars are under-braked if that's the case? That's sort of tongue-in-cheek.. If the rotor doesn't need cooling (or the temp variations are too extreme) then the ducting can still be of benefit in keeping bearing/axle/caliper temps down.

I would also like to know more about how ducting cause your rotor failure and what part of the rotor the ducting was pointed at. I hope it was pointed at the center. I see people who point their ducting right at the face of the rotor blade and IMHO, it's a poor choice to unevenly cool a rotor, just as it to unevenly heat one. Or were you on a track in the dead of winter with a really long straight followed by a 30mph hairpin?

[CSG Mike]

Originally Posted by rice_classic

To me this suggests that professional race cars don't have brakes that are big enough since so many run ducting... But that's not why I'm here.

I need to the see the math or the data to flesh out how lowering the equilibrium = increases temperature spikes. Do you have a resource for this Mike? My experience from the hundreds of cars that run ducting here in the Pacific Northwest is that brake ducting, even on cars with massive rotors, is always good and you can never get enough of it. Rotors/pads/fluid all last substantially longer as a result. I will add that in the PacNW, we don't have any tracks with excessively long straights that we would ever run on in very cold weather. So what you speak of simply may not be a concern in this neck of the woods.

But then again, maybe all cars are under-braked if that's the case? That's sort of tongue-in-cheek.. If the rotor doesn't need cooling (or the temp variations are too extreme) then the ducting can still be of benefit in keeping bearing/axle/caliper temps down.

I would also like to know more about how ducting cause your rotor failure and what part of the rotor the ducting was pointed at. I hope it was pointed at the center. I see people who point their ducting right at the face of the rotor blade and IMHO, it's a poor choice to unevenly cool a rotor, just as it to unevenly heat one. Or were you on a track in the dead of winter with a really long straight followed by a 30mph hairpin?

It really depends on what net effect of the ducting is.

For example, the S2000 has ducts to bring down the equilibrium point low enough that aggressive race pads will not fade, but because the equilibrium temperature is so high, the result is rotors that crack quickly.

On our BRZ with the AP Endurance kit, the braking system is oversized for the car, and ducting is again utilized to bring down the equilibrium temperature, but this time it is so that we can use less aggressive pads without fading. The side benefit is that we can almost use street pads at our current power levels and tires.

Most race cars are using ducting to bring the equilibrium point down to reduce wear, not to prevent fade. The ducts do the same thing, but for different reasons.

[glamcem]

little update about my custom brake cooling duct;
this past weekend I had a chance to test my custom brake ducting (updated routing) and even I ran out of the track couple times and it still held up just fine
as well as my new FT86 front splitter..so for those who are not sure about the sturdiness of the ducting and the splitter, this might be a good news @Model Citizen @ATL BRZ @CSG Mike @rice_classic

I have to mention that I added metal zip ties and intentionally left the plastic ones to see if they melt after some hard track use and they both held up just fine,YMMV

with that said I still had some fading especially when coming close to the T3 but soon after that brakes recover I think it's due to brake cooling, I will also need to address the rubbing issues I will most likely raise the car a little bit..
here is some footage from the last event
some track footage with the splitter and brake ducting

[ame="http://youtu.be/2JDtUJGLag0"]http://youtu.be/2JDtUJGLag0[/ame]

[CSG Mike]

Originally Posted by glamcem

little update about my custom brake cooling duct;
this past weekend I had a chance to test my custom brake ducting (updated routing) and even I ran out of the track couple times and it still held up just fine
as well as my new FT86 front splitter..so for those who are not sure about the sturdiness of the ducting and the splitter, this might be a good news @Model Citizen @ATL BRZ @CSG Mike @rice_classic

I have to mention that I added metal zip ties and intentionally left the plastic ones to see if they melt after some hard track use and they both held up just fine,YMMV

with that said I still had some fading especially when coming close to the T3 but soon after that brakes recover I think it's due to brake cooling, I will also need to address the rubbing issues I will most likely raise the car a little bit..
here is some footage from the last event
some track footage with the splitter and brake ducting

What kind of pads are you on? Sounds like it's time to get some better pads; you're just barely hitting the limits of your pads, and it'll get worse as you get faster.

[glamcem]

Originally Posted by CSG Mike

What kind of pads are you on? Sounds like it's time to get some better pads; you're just barely hitting the limits of your pads, and it'll get worse as you get faster.

I am running XP 12s that I purchased from you guys, remember?
I will most likely need to get a BBK down the road but I am trying to postpone it for a while so that I can attend as many track days in the season. I believe my ducting really helps but when there are multiple hard corners I can feel the brakes fade

[CSG Mike]

Originally Posted by glamcem

I am running XP 12s that I purchased from you guys, remember?
I will most likely need to get a BBK down the road but I am trying to postpone it for a while so that I can attend as many track days in the season. I believe my ducting really helps but when there are multiple hard corners I can feel the brakes fade

Oh wow, yeah, you'll need a BBK soon.

[glamcem]

Originally Posted by CSG Mike

Oh wow, yeah, you'll need a BBK soon.

I might give it a try to Raybestos ST43s as I used them in my previous cars with no issues (other than the obnoxiously loud noise and funny looks from the people)

[Slick]

For anyone running a cooling kit, how did you route your hose?

I managed to source a used kit for a WRX and make it work in terms of the ducting plate at the rotor (see pic below).





But when trying to route the hose, there was no way that I was getting that 3" hose around the wheel/tire and into the front bumper to access the cool air up there. (I'm also running 18x9 with 255 tires, so it's pretty tight in there)

If anyone has pics of their hose routing, I would love to see them.

Here are my current options:

• run directly into the gap behind the engine and mount a flat duct under the car there
• route hose under lower arm and under the suspension, then back up into the bumper cavity through the bottom to the fog light intake
• ??

[ATL BRZ]

Originally Posted by Slick

But when trying to route the hose, there was no way that I was getting that 3" hose around the wheel/tire and into the front bumper to access the cool air up there. (I'm also running 18x9 with 255 tires, so it's pretty tight in there)

If anyone has pics of their hose routing, I would love to see them.

I have lots of pics of my hose routing from my TF Cooling Kit install here: http://www.ft86club.com/forums/showt...749#post881749

I'd recommend using a 2 inch hose with silicone reducers and routing from the front bumper openings around the radiator/condenser on both sides, into the engine bay then cut a small section of your wheel liner out to route it onto the control arms. Touge Factory tried many different methods when designing their kit and this worked the best and makes no additional openings (extra drag) on the front of the car. You could probably contact them and inquire about purchasing their kit minus the backing plates: http://www.tf-works.com/tf-brake-duc...-s-subaru-brz/

[gramicci101]

You went with the 911 GT3 ducts recently, didn't you? How are those working out?

[Slick]

Thanks, that's what I was looking for.
Gonna "hole out" the turn indicator fake vents in the front bumper and route the hose that way.
I didn't really want to be routing the hose into the airflow under the car as I have future plans for some aero.

Originally Posted by ATL BRZ

I have lots of pics of my hose routing from my TF Cooling Kit install here: http://www.ft86club.com/forums/showt...749#post881749

I'd recommend using a 2 inch hose with silicone reducers and routing from the front bumper openings around the radiator/condenser on both sides, into the engine bay then cut a small section of your wheel liner out to route it onto the control arms. Touge Factory tried many different methods when designing their kit and this worked the best and makes no additional openings (extra drag) on the front of the car. You could probably contact them and inquire about purchasing their kit minus the backing plates: http://www.tf-works.com/tf-brake-duc...-s-subaru-brz/

[ATL BRZ]

Originally Posted by gramicci101

You went with the 911 GT3 ducts recently, didn't you? How are those working out?

Haven't been able to track test any of the new gear yet since last Friday at AMP was a bust due to a coil pack failure on my first lap. This Saturday is my next opportunity; fingers crossed. The only feedback I have so far is the air guides are staying put on the control arms at highway speeds and haven't moved at all.

[gramicci101]

Originally Posted by ATL BRZ

Haven't been able to track test any of the new gear yet since last Friday at AMP was a bust due to a coil pack failure on my first lap. This Saturday is my next opportunity; fingers crossed. The only feedback I have so far is the air guides are staying put on the control arms at highway speeds and haven't moved at all.

Take spare coils for 1 and 3!

I havent heard anything from Wonderbar about cutting out a heat shield. I'm still trying to find a diagram showing physical measurements of the coils so I can bug the aftermarket ignition companies about suitable substitutions. I'm sure there's already something developed for another car that would work just fine, it's just a matter of finding it.