Brake cooling ducts

[pkimM3r]

Originally Posted by surlynkid

don't bother with the carbon fiber front ducts for $500. get the apex ones for $200/pair. The GT4 backing plates are not easily available. Only the GT4 dealers in the US can get them. They are over $600 each. The matching hose is 70mm which is Euro purchase only. I got my hoses from a dealership in Belgium. It is 2.75" which i could not find domestically.

the backing plates force air through the rotor vanes. there are tight clearances to assure the air exit the vanes. just plumbing air into the wheelwell seems like a complete waste to me.

Which backing plates do you use?

[surlynkid]

Original BMW Motorsports GT4 backing plates for the E92 M3.

[Richbot]

FWIW, mcmaster.com does sell a few 2 3/4" hose options

http://www.mcmaster.com/#duct-hose/=na0900

[surlynkid]

Originally Posted by Richbot

FWIW, mcmaster.com does sell a few 2 3/4" hose options

http://www.mcmaster.com/#duct-hose/=na0900

high temp versions? That is where I got stuck. Honestly, the ones from europe were the same price as racer parts wholesale or other racing supply shops, so it was a no-brainer besides hauling them back.

just checked. mcmaster carr does not have 2.75" high temp hoses besides some galvanized steel ones.

[LiM3y]

Go to www.aircraftspruce.com and search ducts or ducting. They have all the ducting in different sizes and materials you could ever want. They also have aluminium flanges for hooking stuff up too.

[aus]

Originally Posted by 1MOREMOD

i made my own using apex gt4 ducts and bought rest of my parts from summit. ended up doing 3 inch the whole way which was a mistake due to excessive rubbing. works fine for a non street car but turning radius is greatly reduced.

Does the 3" fit through the undertray piece? I'm thinking of doing what Richbot mentions below.

Originally Posted by Richbot

Some on here have seen big improvements with just a 2.5 or 3" hose routed to the fender liner the way just about all BMW's are set up, except on our inexplicably ductless cars. You don't necessarily have to go with backing plates to get most of the benefit of ducting when you're starting with zip for cooling (like we have from the factory for some reason). For a street car that's where I'd stop, coupled with a better pad, if I wanted to stay with the stock brakes anyway, but that Stoptech front 355 kit is so reasonably priced relative to a $800 stock front brake job, kinda makes it hard to ignore the opportunity to upgrade unless you really just want to stay stock or are really sticking to a budget

I'm thinking this is good enough paired with a BBK. What did you use on the back side of the undertray to secure the duct?
Thanks.

It just amazes me we have no ducts at all. E46 had then blocked off, but at least they were there.

.

[1MOREMOD]

Originally Posted by aus

Does the 3" fit through the undertray piece? I'm thinking of doing what Richbot mentions below.



I'm thinking this is good enough paired with a BBK. What did you use on the back side of the undertray to secure the duct?
Thanks.

It just amazes me we have no ducts at all. E46 had then blocked off, but at least they were there.

.

yes the 3 inch fits thru. i used 3 inch universal clamps from summit racing to secure the hose to the inside of the undertray in the fender liner area.

[03///m3]

Does anyone know if the OEM bmw performance front splitters block the area below where the air ducts would be installed on the bottom of the front spoiler? In other words would installing the front splitters prohibit you from installing brake ducts?

[SpiralOut]

Originally Posted by 03///m3

Does anyone know if the OEM bmw performance front splitters block the area below where the air ducts would be installed on the bottom of the front spoiler? In other words would installing the front splitters prohibit you from installing brake ducts?

Pretty sure they do block that spot yes.

[03///m3]

Originally Posted by SpiralOut

Pretty sure they do block that spot yes.

That sucks

[Modena NYC]

Originally Posted by 03///m3

That sucks

Hahaha

I find it hilarious how difficult a solution is.

[surlynkid]

Originally Posted by 03///m3

Does anyone know if the OEM bmw performance front splitters block the area below where the air ducts would be installed on the bottom of the front spoiler? In other words would installing the front splitters prohibit you from installing brake ducts?

yup. that is why I sold my splitters before installing them. pretty stupid design when one group does not confer with the other group all within the same company.

[Car54]

Originally Posted by apecush

how are your front caliper seals? A few 30 minute sessions with no ducting and with track pads made short work of them. no fade though...

Pistons seals or dust boots? There's a difference.

With wheel well ducting, track pads, and street tires I have no issues with fade.

[apecush]

Originally Posted by Car54

Pistons seals or dust boots? There's a difference.

With wheel well ducting, track pads, and street tires I have no issues with fade.

sorry, boots.

I'd be scared if I was melting seals...

[CSBM5]

Originally Posted by apecush

how are your front caliper seals? A few 30 minute sessions with no ducting and with track pads made short work of them. no fade though...

Use some Ti shields between the backing plate and the piston. It will likely solve most if not all of your problem. I've been using them for 10 years on various cars with great success (reducing heat transfer to the piston, shielding (from a radiation heat transfer standpoint) the dust boots from "seeing" the hot pad backing plate surface, etc. They are especially effective as your pad thickness wears down since the pad material is a highly effective insulator, so as the pad thickness decreases the backing plate temperature (and therefore piston temperature) goes up...a lot by the time the pads are thin.