Brake Cooling Question - BMW 3-Series (E90 E92) Forum

DSC_OFF · 11-09-2012, 10:19 AM

About to tackle my first winter project which is to add brake cooling but had 2 questions:

1. It seems most backing plates are "optimized" for 3" hoses. What are your thoughts of running a 3" to 2.5" reducer/coupler on the backing plate so that I can use a 2.5" hose instead? I prefer 2.5" because it's less likely to kink or rip. My concern however is loss of pressure...

2. I see that you typically have the option for silicone (high-temp) vs neoprene (limited to 300*), the latter being half the price. Is high-temp really necessary?

DallasBoosted · 11-09-2012, 12:38 PM

I'd think for the coupler thats going to attach to the spindle duct, you'd want more temp handling because it will be so close to the rotors. For the hose beyond that coupler, whatever material should be fine.

If 2.5" hose fits and you don't rip it off every other weekend turning your wheels, then thats better. There's no sense in running bigger hose if it pisses you off and you end up taking it off all the time. Run what you can leave on 24/7/365.

DSC_OFF · 11-09-2012, 01:15 PM

Thanks, ideally I'd like to avoid paying up for any expensive backing plate and just stick on a 2.5" flange onto my existing oe plate. However, the plate on my car isn't flat throughout and any flat area is too far out, not close enough to the hub. I know it's easy to bend the material but have to first see nothing will get in the way. Else I may have no choice but to buy an expensive Turner/BW plate and use the coupler.

The hi-temp hoses are good up to 600*, the standard is 300*. The high temp couplers I've found (used for intakes, turbos, etc) are good for 500* so I think I'm ok on that front.

neilvosko · 11-09-2012, 09:38 PM

Quote:

Originally Posted by DSC_OFF

Thanks, ideally I'd like to avoid paying up for any expensive backing plate and just stick on a 2.5" flange onto my existing oe plate. However, the plate on my car isn't flat throughout and any flat area is too far out, not close enough to the hub. I know it's easy to bend the material but have to first see nothing will get in the way. Else I may have no choice but to buy an expensive Turner/BW plate and use the coupler.

The hi-temp hoses are good up to 600*, the standard is 300*. The high temp couplers I've found (used for intakes, turbos, etc) are good for 500* so I think I'm ok on that front.

I experimented with custom brake ducts just for fun and just sold mine as I am going to a dedicated track car. Lessons learned: use 2.25 inch, 3 inch will run on tires at full lock. I used a silicone coupler to attach neoprene dual coated ducts to the flange on backing plate to get beat of both worlds. Place flange close as possible to center I backing plate for more air. You can also bend the backing plate inward to get more air. Remove plastic shrouds around Intercooler that are useless and put the tubing there.

Whew

neilvosko · 11-09-2012, 09:39 PM

Get racing brake pads

DSC_OFF · 11-09-2012, 10:34 PM

Quote:

Originally Posted by neilvosko

Get racing brake pads

I already have

wonho · 11-10-2012, 11:44 AM

just short input: (small) reduction of pipe cross section area most likely will not affect the volume flow rate of air going in; it compensates by increasing the flow velocity at the smaller end. Since the pipes will always have bends, drag due to vends restrict more than the drag from reduction of diameter, hence I'd say tapering down to even 2" is no prob.

neilvosko · 11-10-2012, 12:58 PM

+1, faster flow is even better for cooling.

N54_Fan · 11-14-2012, 08:19 PM

Quote:

Originally Posted by neilvosko

I experimented with custom brake ducts just for fun and just sold mine as I am going to a dedicated track car...

You sold your car?...Funny, I am going to a dedicated track car as well. But I decided to keep my car as a DD and just start over modding a dedicate track car. This car is just too heavy and too expensive to maintain compared to many cars that would do well on the track.

May I ask what you are buying for the track?

N54_Fan

neilvosko · 11-14-2012, 09:35 PM

just sold the brake ducts. kept the e92.

looking for e36

i actually have removed all the plastic around intercooler and still have the holes from brake ducts so still getting decent air to brakes.

i was getting lots of misfires and LP sensor errors recently, so want to fix this before heading to track. i cant wait for the F32 and maybe turn this beast into track queen. just get coilovers and a roll cage.

Rotary Rocket · 12-02-2012, 02:25 PM

Mazdaspeed did some experimentation with brake ducts in the early 80s. They concluded 3 inch hose was min for brake cooling. Anything less in diameter simply did not pass enough air to be effective.

Adding cooling hoses does usually come with the headache of rubbing on full lock. The temps on hoses are not that important. The rubbing of the tire will wear your hose out first. The more expensive stuff will just last longer.

I highly recommend cooling hoses, one to the center of the brake disc (spend the money for the backing plate), and if you can one to the caliper. The caliper hose only if you are a hardcore track rat and are very hard on your brakes.

I buy my hoses in 30 ft lengths and change them once per year. This is for my race car. During the season I wrap ductape around the sections of the hose that get haggered to make them last for the season.

Good luck.

neilvosko · 12-09-2012, 11:11 PM

Yep, duct tape will help.

If you don't go with duct you you can bend the backing plate to get more air to rotors.

DSC_OFF · 01-24-2013, 11:02 PM

Finally got around to completing this project

http://www.zpost.com/forums/showthread.php?t=794394

HP Autowerks · 03-01-2013, 02:36 AM

Quote:

Originally Posted by DSC_OFF

Finally got around to completing this project

http://www.zpost.com/forums/showthread.php?t=794394

Are those AST 4200's I see or 5100's?

11-09-2012, 10:19 AM	#1
DSC_OFF Major General Drives: flat out Join Date: Apr 2008 Location: NNJ Posts: 5,636 iTrader: (30) Garage List 2007 BMW Z4 3.0si c ... [4.62]	Brake Cooling Question About to tackle my first winter project which is to add brake cooling but had 2 questions: 1. It seems most backing plates are "optimized" for 3" hoses. What are your thoughts of running a 3" to 2.5" reducer/coupler on the backing plate so that I can use a 2.5" hose instead? I prefer 2.5" because it's less likely to kink or rip. My concern however is loss of pressure... 2. I see that you typically have the option for silicone (high-temp) vs neoprene (limited to 300), the latter being half the price. Is high-temp really necessary? __________________ Recaro \| AST \| Vorshlag \| Quaife \| Stoptech \| Volks \| Autosolutions \| BMW Performance* Click here for my track videos Last edited by DSC_OFF; 11-09-2012 at 12:34 PM.
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11-09-2012, 01:15 PM	#3
DSC_OFF Major General Drives: flat out Join Date: Apr 2008 Location: NNJ Posts: 5,636 iTrader: (30) Garage List 2007 BMW Z4 3.0si c ... [4.62]	Thanks, ideally I'd like to avoid paying up for any expensive backing plate and just stick on a 2.5" flange onto my existing oe plate. However, the plate on my car isn't flat throughout and any flat area is too far out, not close enough to the hub. I know it's easy to bend the material but have to first see nothing will get in the way. Else I may have no choice but to buy an expensive Turner/BW plate and use the coupler. The hi-temp hoses are good up to 600, the standard is 300. The high temp couplers I've found (used for intakes, turbos, etc) are good for 500* so I think I'm ok on that front. __________________ Recaro \| AST \| Vorshlag \| Quaife \| Stoptech \| Volks \| Autosolutions \| BMW Performance Click here for my track videos

01-24-2013, 11:02 PM	#13
DSC_OFF Major General Drives: flat out Join Date: Apr 2008 Location: NNJ Posts: 5,636 iTrader: (30) Garage List 2007 BMW Z4 3.0si c ... [4.62]	Finally got around to completing this project http://www.zpost.com/forums/showthread.php?t=794394 __________________ Recaro \| AST \| Vorshlag \| Quaife \| Stoptech \| Volks \| Autosolutions \| BMW Performance Click here for my track videos

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11-09-2012, 12:38 PM	#2
DallasBoosted Captain Drives: '08 E92 335i Join Date: Apr 2012 Location: Dallas Posts: 715 iTrader: (2) Garage List 2008 BMW 335i [5.00]	I'd think for the coupler thats going to attach to the spindle duct, you'd want more temp handling because it will be so close to the rotors. For the hose beyond that coupler, whatever material should be fine. If 2.5" hose fits and you don't rip it off every other weekend turning your wheels, then thats better. There's no sense in running bigger hose if it pisses you off and you end up taking it off all the time. Run what you can leave on 24/7/365.

11-09-2012, 09:39 PM	#5
neilvosko Major Drives: 335i e92 FBO Join Date: Dec 2011 Location: miami Posts: 1,174 iTrader: (12)	Get racing brake pads

11-10-2012, 11:44 AM	#7
wonho NOT two hoes Drives: E46M Join Date: Mar 2011 Location: Central Jersey Posts: 388 iTrader: (4)	just short input: (small) reduction of pipe cross section area most likely will not affect the volume flow rate of air going in; it compensates by increasing the flow velocity at the smaller end. Since the pipes will always have bends, drag due to vends restrict more than the drag from reduction of diameter, hence I'd say tapering down to even 2" is no prob.

11-10-2012, 12:58 PM	#8
neilvosko Major Drives: 335i e92 FBO Join Date: Dec 2011 Location: miami Posts: 1,174 iTrader: (12)	+1, faster flow is even better for cooling.

11-14-2012, 09:35 PM	#10
neilvosko Major Drives: 335i e92 FBO Join Date: Dec 2011 Location: miami Posts: 1,174 iTrader: (12)	just sold the brake ducts. kept the e92. looking for e36 i actually have removed all the plastic around intercooler and still have the holes from brake ducts so still getting decent air to brakes. i was getting lots of misfires and LP sensor errors recently, so want to fix this before heading to track. i cant wait for the F32 and maybe turn this beast into track queen. just get coilovers and a roll cage.

12-02-2012, 02:25 PM	#11
Rotary Rocket Private Drives: 99 M3 USTCC Join Date: Dec 2011 Location: California Posts: 54 iTrader: (0)	Mazdaspeed did some experimentation with brake ducts in the early 80s. They concluded 3 inch hose was min for brake cooling. Anything less in diameter simply did not pass enough air to be effective. Adding cooling hoses does usually come with the headache of rubbing on full lock. The temps on hoses are not that important. The rubbing of the tire will wear your hose out first. The more expensive stuff will just last longer. I highly recommend cooling hoses, one to the center of the brake disc (spend the money for the backing plate), and if you can one to the caliper. The caliper hose only if you are a hardcore track rat and are very hard on your brakes. I buy my hoses in 30 ft lengths and change them once per year. This is for my race car. During the season I wrap ductape around the sections of the hose that get haggered to make them last for the season. Good luck.

12-09-2012, 11:11 PM	#12
neilvosko Major Drives: 335i e92 FBO Join Date: Dec 2011 Location: miami Posts: 1,174 iTrader: (12)	Yep, duct tape will help. If you don't go with duct you you can bend the backing plate to get more air to rotors.