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Discussion Starter · #1 ·
Just wondering how much of this air is cooling the engine.

Why you ask?

I am trying to design a CAI kit that I think would be 10x better than anything out there but it would block off that opening for any air to get past.

Let me know if this is a bad idea.

If you think it is a good idea...do you have a spare bumper grill I can use to design the CAI?

Cheers.

Ryan
 

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sounds like your trying to design a ram air system. if you use the entire opening, i think there would definatley be some engine colling issues. i'm sure others will know more.
 

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Discussion Starter · #4 ·
Ag Surfer said:
sounds like your trying to design a ram air system. if you use the entire opening, i think there would definatley be some engine colling issues. i'm sure others will know more.
I think you are right. Just wanted to bounce it off some other folks.

I have a feeling it is going to be sink drains. ;)

R
 

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if you mean the grill down in the bumper, where the brake ducts would be, that's the majority of the radiator cooling air comes from. wouldn;t want to block that off. You could use the fog lamp area though. I had cobbled up an air intake that went into the fog lamp area (I removed the fog lights). the car did seem to run well, but i kept getting mafs fault codes (non plausible readings or something like that) after any moderately high speed run 70-80mph.
Mike
 

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Ag Surfer said:
sounds like your trying to design a ram air system. if you use the entire opening, i think there would definatley be some engine colling issues. i'm sure others will know more.
I am not an expert either, but I agree with Sean that blocking the entire lower opening would probably have a negative impact on cooling the motor.

Good luck!
Alfred
 

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Messing with the cooling or aerodynamics of the car seems quite foolish to me. The only reason I would consider brake ducts is because the European M5's have them. Even then, it leaves a little doubt in my mind regarding messing with the high speed stability/performance.

Any thoughts on this?

Travis
 

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M5Kid said:
Messing with the cooling or aerodynamics of the car seems quite foolish to me. The only reason I would consider brake ducts is because the European M5's have them. Even then, it leaves a little doubt in my mind regarding messing with the high speed stability/performance.

Any thoughts on this?

Travis
I think the difference in aerodynamics is trivial with the ducts open. I spent a former life designing V/STOL inlet shapes for an F-15 inlet, so I've got a bit of experience with fluid flow. The brake duct flow into the fenderwell will have essentially no impact of the stability of the car and essentially no measureable impact on the Cd of the car either imo.

Chuck
 

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M5Kid said:
Messing with the cooling or aerodynamics of the car seems quite foolish to me. The only reason I would consider brake ducts is because the European M5's have them. Even then, it leaves a little doubt in my mind regarding messing with the high speed stability/performance.

Any thoughts on this?

Travis
actually, the euro cars also have closed brake ducts. The only e39's with them open are the non-M cars. we essentially use standard 5 series ducts and fenderwell liners to have open ducts.

while they do admit some air into the fenderwell area, they are quite a ways away from the caliper/rotors, so you could argue their effetivness. They're probably better at tire tread cooling!
Mike
 

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Discussion Starter · #10 ·
mottati said:
while they do admit some air into the fenderwell area, they are quite a ways away from the caliper/rotors, so you could argue their effetivness. They're probably better at tire tread cooling!
Mike
I'm still unclear as to where the factory brake ducts mount to the bumper...any light to shed there? Is it by the fog lamp or more by the grill of which I was speaking?

Thanks.

Ryan
 

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Ag02M5 said:
I'm still unclear as to where the factory brake ducts mount to the bumper...any light to shed there? Is it by the fog lamp or more by the grill of which I was speaking?

Thanks.

Ryan
it's in the grill, the outer part. If you look at the stock grill, there is the open section in the middle, for engine cooling, then there are the closed off parts on either side. Those are what you open to get the brake cooling ducts to function.
mike
 

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Discussion Starter · #12 · (Edited)
mottati said:
it's in the grill, the outer part. If you look at the stock grill, there is the open section in the middle, for engine cooling, then there are the closed off parts on either side. Those are what you open to get the brake cooling ducts to function.
mike
Ok. That is what I thought.

So no good way to have CAI that goes all the way to grill and brake duct unless you move inlet rings for CAI more toward center.

Or use the area by fog lights. Wonder how to mount to that area????

Cheers.

:cheers:
 

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Ag02M5 said:
I'm still unclear as to where the factory brake ducts mount to the bumper...any light to shed there? Is it by the fog lamp or more by the grill of which I was speaking?

Thanks.

Ryan
My AA install pictures should show you what you want to know. The stock brake duct doesn't have the opening the side for the AA intake plenum, it's just solid.






 

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Discussion Starter · #14 ·
THANKS HDClown!!!

That is the shizzle!

Ok I think I finally understand how the AA kit works...so the air comes in the inlet rings which are purely show and dont connect to anything. The brake duct is behind the ring. Some air goes straight through to brake and some through hole in side of duct and up into intake.

Is that accurate?

Seems like the air will take the path of least resistance and go through but then the engine probably sucks it in.

I think I'd rather have the inlet tubes for the intake go all the way to the ring in the front.

Thanks again.

Ryan

Please let me know if I am missing something
 

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Yes, you got it. AA modified a STOCK brake cooling duct and cuts a hole in the outter side and put in a clamping ring for a new air trumpet. They provide you with the OEM brake duct extensions (the black pieces) which wedge in between the front bumpers lower grille (behind the the holes in the AA CAI provided grill) and the frnt of the brake duct.

Air goes in the hole via ram air effect, through the extension and into the metal duct. Some air goes out the back into the wheel well, and some goes out the side. For me, I didn't cut the wheel well liner, so all my air hits the liner and thus only goes out the right hand side into the intake trumpet. There is obviously some air leak from the wheel well.

Someone did bypass the brake duct entirely, running the AA intake trumpets directly to the ring in the AA lower grille. The trumpets are longer enough to do this. He did this by jacking the car up and connecting the trumpet to the grill. You can't do this without the bumper on, so it's the only way. You also need to remove the plastic brake duct extensions to do this.

If you do that, then you really have the most direct intake you could possibly find, without having to modify parts of the car to shorten the intake trumpet path for less bends. You also still get a ram air effect by doing this.
Ag02M5 said:
THANKS HDClown!!!

That is the shizzle!

Ok I think I finally understand how the AA kit works...so the air comes in the inlet rings which are purely show and dont connect to anything. The brake duct is behind the ring. Some air goes straight through to brake and some through hole in side of duct and up into intake.

Is that accurate?

Seems like the air will take the path of least resistance and go through but then the engine probably sucks it in.

I think I'd rather have the inlet tubes for the intake go all the way to the ring in the front.

Thanks again.

Ryan

Please let me know if I am missing something
 

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M5Kid said:
Mike,

Fair statement to say that the brake ducts have minimal if any affect on cooling the brakes?

Travis
Probably none. They're probably more effective at blowing brake dust around as it comes off the pads. Perhaps they help keep some dust off your wheels, but the distance between the calipers/rotors and the opening in the wheel well liner is a good 6" or more.

If you want to make the duct effective, you'd want to attach a piece of flexible hose from that opening so that it points directly over the caliper (a la a race car). It would be difficult to do I'd imagine, considering where the brake duct opening is in the wheel well and how tight it is in there.
 
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