Brake cooling ducts

Argenta

Senior member
Hello all!
I've been lurking long enough, first post here and this seems like a much nicer forum than our swedish alternatives! :)
Have had my interlagos blue Z4M Coupe '06 since december and one of my questions is on the brake cooling ducts;
Why are they 80% covered from factory, and are people taking these covers off for track-day use etc..?
 
Many people do and actually some cars came from the factory with them unblocked completely. I'm sure members who have done it will come in with their advice shortly. I didn't do it for my car.
 
mine were unlocked from factory. never touched them and they are completely open and were moulded that way.
 
Thanx for the reply's, has anyone heard any pro's/con's re track use with these open..?
I'm just hoping they actually help cooling?
 
I don't recall having read anything saying they make much of a difference... Ideally you could try unblocking just one and after some laps stop and immediately check both disc's temperature to be 100% sure it does actually make a difference. The only other ways I know of for proper brake cooling on Z4s is either the method described by exdos here or the method by Dubbedown here.
 
Do you mean the openings in the front bumper that lead to the wheel arch liner? Can't believe they do anything. You'd need to run properly routed and fixed trunking to feed the air directly into the centre of the disc.

I was thinking about doing this as a little project.
 
tertius said:
Do you mean the openings in the front bumper that lead to the wheel arch liner? Can't believe they do anything. You'd need to run properly routed and fixed trunking to feed the air directly into the centre of the disc.

I was thinking about doing this as a little project.

That would be quite useful, but would be a tight fit. Not a whole load of room between the wheel and arch
 
Viren said:
tertius said:
Do you mean the openings in the front bumper that lead to the wheel arch liner? Can't believe they do anything. You'd need to run properly routed and fixed trunking to feed the air directly into the centre of the disc.

I was thinking about doing this as a little project.

That would be quite useful, but would be a tight fit. Not a whole load of room between the wheel and arch

Think you have to route from elsewhere - not directly from those intakes - see the link to the Exdos thread posted above.
 
Hi buddy!
This article may explain the woodo behind these vents. http://articles.sae.org/12878/
If it has an aerodynamic purpose, reducing drag, I wouldnt touch it.
 
Hej Yeddheng! :)
Yes its a bit like the inlets on certain variants of Alfa 4C, but they are a lot more outboard.
On the 1-series M bumpers they point straight toward the brakes. On the Z4M somewhere in between.. Oh well I suppose its up to anyone to try out then.
But interesting to know some came fully open from factory!
 
I doubt the OEM brake ducts do anything. Certainly, there's no space to direct the air flow to the calipers using trunking due to the proximity of the tyre. I've run reinforced heat resistant tubing from the bumper to the front calipers but I'm unconvinced that even this is of more than very modest benefit. I modified the method described by Exdos. I don't have photographs of the ducting to hand but here's how mine opens into the ///M bumper (complete with dead flies):

6a72a281-ca8d-4192-ae6a-a5566e2ef0d7_zpsehlu8of6.jpg

I'm quite pleased with the overall appearance (ignore the yellow stripe on my track wheels):

a3730c7c-410a-4247-a575-ebd62d6836f3_zpsw40edg2f.jpg
 
Cheers Argenta :thumbsup: It's on KW Clubsports which is a track-focused, fully adjustable set up. I was running Eibach springs previously and currently it's lowered about the same amount but with slightly more rake.
 
From my own experimentation and testing of the dynamic air pressure changes at different speeds and with different configurations of blanking of the OEM brake ducts, particularly with the Z3MC, I think that the OEM blanking of the Z4MC's brake ducts is primarily to increase the aerodynamic function of the "fangs" as front splitters. If the brake ducts were not present in the front bumper, then to obtain the same increase in dynamic air pressure at the front of the car (i.e. downforce) would require much larger protruding front flippers. This would significantly alter the aesthetics of the front bumper.

If you want to improve brake cooling then install some ducting directly to the centres of the discs as described here: http://www.z4-forum.com/forum/viewtopic.php?f=24&t=38775&hilit=brake+cooling+ducts+exdos
 
Exdos, thanks for info and link!
Sort of the same set up I used on my Fiat Coupe (another one in severe need of front brake cooling.. And it didn't even have std inlets for it as they were occupied for oil+IC)
 
Beedub said:
they are only good at cooling your tyres!! lmao!
100% correct

Because the OEM Z4M brake ducts are not the greatest in cooling the brakes I looked for something extra. I never had fading with the AP & Pagid set-up. But on some tracks the Pagid brake pads and AP disc were getting really hot. Sometimes I had a vibration steering wheels after some intensive hot laps (the brake pads get a little to hot and some pad material got stuck on the AP discs) . The extra cooling helps to address this problem… Even with my full AP racing kit the extra brake cooling had some really positive effect (on track)… At the picture you can see my extra cooling holes beside the original ones.

z93w.jpg
 
Looks like you've brought out your cooling ducts where I have mine rather than the "stealth" ducts as per Exdos.
 
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