Another brake duct cooling thread (lite)

[Car54]

I drive this car on the street mostly and didn't want to run full ducts with backing plates. My approach was a little more conservative and took cues from the E36/46 M's.

Parts used were Apex inlet, some Jegs brake ducting, and Allstar flanges.

One of the holes of the flange was reused from the existing screw/clip nut.

I did not have to remove the splash shield, but did have it on a lift and didn't have the front tires on. In addition, I pulled the stock backing plates away from the rotor.

[warp10]

Could you post some more detailed step by step?

[CanAutM3]

Iterresting approach, I like it . Seems like a simpler installation and no issues with rubbing. It most probably is not as efficient as a full backing plate setup but it should improve cooling a little. I use my car in the winter, so a full backing plate setup is out of the question for me. This could be an alternative.

Please post an update after you ran it at the track .

[surlynkid]

i would say that it will do very little. it looks nice with no tire, but put a tire in the way, and you will get negligible airflow to the vanes of the rotor where it is needed.

[Car54]

Originally Posted by surlynkid

i would say that it will do very little. it looks nice with no tire, but put a tire in the way, and you will get negligible airflow to the vanes of the rotor where it is needed.

I measured it up and the wheel well port is inboard of a 9.5" wheel with a 275 tire that is offset right up to the strut. Getting fresh air into the wheel well must help some...it's been standard on M's up until the E90.

[Car54]

Originally Posted by warp10motorsports

Could you post some more detailed step by step?

There's not much to it.

Cut holes in the front, install inlets, connect 3" hose to the back, cut a hole in the wheel well liner, attach hose.

If you use the existing screw hole in the wheel well to line the port up, you'll be in the right spot.

The port comes into the wheel well about 3" higher than the front port.

I would suggest ordering some c-clip nuts ahead of time. Luckily I had a good variety on hand.

http://componentparts.co.uk/Spring%2...0Fasteners.htm

[sleepless]

Originally Posted by Car54

Getting fresh air into the wheel well must help some...it's been standard on M's up until the E90.

And was nearly useless; probably why BMW didn't bother for E9X...

[Car54]

Originally Posted by sleepless

And was nearly useless; probably why BMW didn't bother for E9X...

The E9X has the biggest and most advanced brakes and is the first M3 that brakes are an area of concern. Coincidence that there's a deficiency?

[Autobahn335i]

Originally Posted by Car54

The E9X has the biggest and most advanced brakes and is the first M3 that brakes are an area of concern. Coincidence that there's a deficiency?

Hint: maybe the E9x just weighs too much

And BMW's floating piston design is subpar. I wouldn't call that advanced.

[pbonsalb]

But that single piston floater is better than some six piston calipers. BMW took the 6 piston calipers off the 135i and put the single piston floater on when it made the 1M.

[Autobahn335i]

Originally Posted by pbonsalb

But that single piston floater is better than some six piston calipers. BMW took the 6 piston calipers off the 135i and put the single piston floater on when it made the 1M.

That's because BMW re-used the whole M3 suspension F+R on the 1M. It's about cost-effectiveness. Not about these brakes being so awesome.

Additionally the 1M weighs quite a bit less than the E9x M3.

The OPs approach is nice, but if you really put the OEM brakes to the test on a racetrack and push the car to its limit, this cooling will not save you.

[Richbot]

The E9x is not the first M3 to have brakes that aren't up to hard track duty. I don't know of any generation of M3 that doesn't fade its brakes after 5-6 laps on a track with a driver that is actually using the brakes.

[Car54]

Originally Posted by Richbot

The E9x is not the first M3 to have brakes that aren't up to hard track duty. I don't know of any generation of M3 that doesn't fade its brakes after 5-6 laps on a track with a driver that is actually using the brakes.

You must be talking pad composition. The stock hardware is used on many many many race cars as well as track cars. There's a lot of debate as to whether aftermarket stainless lines are even better than OEM.

Maybe if the driver is (over)using the brakes this is the case, but is that really the goal? Again, I don't think the E9X M3's are included in this analysis. E30/36/46's...are quite capable...even the non-M's.

[Car54]

Originally Posted by Autobahn335i

Hint: maybe the E9x just weighs too much

And BMW's floating piston design is subpar. I wouldn't call that advanced.

No doubt about the porkiness...but the brakes are bigger too. The rotor, hat, and design of the E9X are more advanced that other previous 3 series have.

[Porschefile]

The rotor design on the E9X M3 sucks. They use a two piece mounting technique that covers up half of the freaking cooling vanes.

[Richbot]

Just the facts ma'am:

E46 M3 at 3500lbs with driver braking from 135 mph for a 60 mph corner needs to dissipate approximately 550kcal of kinetic energy. E92 M3 braking from 145mph for the same corner needs to dissipate approximately 705kcal of kinetic energy. That's a ~7% increase in weight and speed and ~45% increase in heat load on the brakes. The E92 brakes are bigger but they aren't 45% bigger, and at bigger tracks the speed gap is even more significant. Faster cars are harder on equipment, k=mv^2. BMW had a choice to provide everything from a setup for a 150mph car with a sensitive driver to manage on track to one that can throw down qualifying laps for a whole race distance on a 100 degree day running 6" from another car's bumper. One is what we have from the factory, the other would probably need to be water cooled to fit under 18" wheels.

[Car54]

Originally Posted by Richbot

Just the facts ma'am:

E46 M3 at 3500lbs with driver braking from 135 mph for a 60 mph corner needs to dissipate approximately 550kcal of kinetic energy. E92 M3 braking from 145mph for the same corner needs to dissipate approximately 705kcal of kinetic energy. That's a ~7% increase in weight and speed and ~45% increase in heat load on the brakes. The E92 brakes are bigger but they aren't 45% bigger, and at bigger tracks the speed gap is even more significant. Faster cars are harder on equipment, k=mv^2. BMW had a choice to provide everything from a setup for a 150mph car with a sensitive driver to manage on track to one that can throw down qualifying laps for a whole race distance on a 100 degree day running 6" from another car's bumper. One is what we have from the factory, the other would probably need to be water cooled to fit under 18" wheels.

You're defending the well known position that the E9X brakes are not nearly as capable as the earlier cars. I'm trying to help get some more cooling to them with at least the same method as the earlier cars.

[Richbot]

I'm not defending anything. If you feel like adding a duct helps your brakes, which it probably does, more power to you. But the idea that the previous M3's came with brakes that would withstand the rigors of racing is objectively false, and anyone with an earlier M3 not constrained by rules or finances is likely to, and in most cases I've come across has made the same choices many here have made, and that's to upgrade.

The point I was making with the post you quoted is that the challenge faced by M engineers was to design a cost-effective system that would stand up on the track to a car which requires nearly 50% more heat capacity to slow down because it is much faster in a straight line than the outgoing model, and heavier to boot. They've accomplished that, as proven by many people who haven't died when using them on the track with upgraded pads and fluid or even with stock pads and a measured approach to brake management.

FWIW, I would do the same thing if I felt the need. Pads/fluid and a little air are probably all the car needs until you're serious about doing repeatable lap times and at that point it's smarter to get something that doesn't have a trunk or a roof or windows any of that other useless crap on it. I too was surprised to find that my wife's 335xi has the same ducts all of my previous BMW's have had on them and the full-Jesus M3 doesn't. But my E36 and E46's would both burn the brakes down after more than 3-4 hot laps unless you were intelligent about brake management

[TXmtrhed]

Originally Posted by CanAutM3

Iterresting approach, I like it . Seems like a simpler installation and no issues with rubbing. It most probably is not as efficient as a full backing plate setup but it should improve cooling a little. I use my car in the winter, so a full backing plate setup is out of the question for me. This could be an alternative.

Please post an update after you ran it at the track .

I have been thinking about doing this myself to keep things simple and eliminate rubbing (I have to turn full lock everyday when I park).

Not sure if any of you have seen this but the F30 comes with a backing plate that really opens up inward to "scoop" more air. I thought I might try adapting this backing plate to my car and combine with the hoseless ducts. Not sure of the backing plate diameter versus the E9x M3 diameter but it's probably close enough.

http://www.1addicts.com/forums/showt...+backing+plate

[pbonsalb]

Originally Posted by CanAutM3

Iterresting approach, I like it . Seems like a simpler installation and no issues with rubbing. It most probably is not as efficient as a full backing plate setup but it should improve cooling a little. I use my car in the winter, so a full backing plate setup is out of the question for me. This could be an alternative.

Please post an update after you ran it at the track .

Why can't you use a backing plate in the winter if you remove the ducting? I have backing plates on my turbo E36M3 and drive it in the winter with no ducting. I do not cap the duct tubes on the plates, though I suppose I could.

[bigjae1976]

If you ask me, BMW eliminated the cooling to reduce air turbulence in the wheel well...an MPG thing. BMW has been big about wheel area turbulence which explains the slots on the sides of the 1M bumper.

BMW probably thought better air flow management in the wheel wells is better than the limited effect of the brake ducts.

[TXmtrhed]

Originally Posted by bigjae1976

If you ask me, BMW eliminated the cooling to reduce air turbulence in the wheel well...an MPG thing. BMW has been big about wheel area turbulence which explains the slots on the sides of the 1M bumper.

BMW probably thought better air flow management in the wheel wells is better than the limited effect of the brake ducts.

It will be interesting to see if the new M3 has brake ducts as does the new F30 because it appears that it will use the air curtain slots (not seen on the F30).