Track pad advice please
- Thread starter BMWZ4MC
- Start date
I only cut the blanks out a couple of months ago and I haven't had the car on the track this year yet (unfortunately the local Calgary track closed last year and the new Edmonton track 250km away is not due to be finished until mid summer), but my plan is to tape over the opening and use my IR thermometer to look at changes.exdos said:
You can do some testing of the efficacy on public roads even at legal driving speeds to get an idea. Just tape over one duct so that it replicates the OEM blanking. Then do some driving, deliberately braking a few times in short succession, a bit like the bedding in process of new pads, and finish with a hard braking event from the highest permitted legal speed to a halt then immediately take temperature readings of the brakes on both sides, particularly the discs. If there's a difference of more than 20 degs C between sides, then there is a significant effect of removing the blanking plates.aerobod said:
Exdos; lower.
What about EXPELLING air faster from the wheelarch? I can see all racing cars now have massive vents behind the front wheel arch. Its all good thinking of methods getting a good airflow to the hub but ion the end by increasing it we will just build up the pressure on the wheelarch presumably.
One thing is sure though is that as we brake (unless trail braking) in a straight line, those massive brake cooling duckts in the front bumper would not be so effective?
I absolutely hate that BMW roundel / signal light in the front wheel. would that be a good placement to expell hot air built up in the wheel arch?
What about EXPELLING air faster from the wheelarch? I can see all racing cars now have massive vents behind the front wheel arch. Its all good thinking of methods getting a good airflow to the hub but ion the end by increasing it we will just build up the pressure on the wheelarch presumably.
One thing is sure though is that as we brake (unless trail braking) in a straight line, those massive brake cooling duckts in the front bumper would not be so effective?
I absolutely hate that BMW roundel / signal light in the front wheel. would that be a good placement to expell hot air built up in the wheel arch?
ChawenHalo said:
Yes, by allowing air at ambient temperature under ram pressure directly into the wheel arches when the car is moving will generally assist in keeping the temperature under the wheel arches much cooler than would otherwise occur. The air travelling beneath the car is at lower pressure because it is travelling faster, and so if there is any tendency to build up in pressure in the wheel arches, it will be "neutralised" by the lower pressure beneath the car which will draw air from the wheel arches by the Venturi Effect.
That's correct. Only ducted air-cooling can overcome this problem, but I doubt if any production car would have that solution as OEM equipment. The only problem with the brakes overheating is when the "duty cycle" between hard braking events is short so that the cooling intervals are insufficient to prevent a continuous rise in the temperature of the brakes (discs, pads and fluid) so that they eventually exceed maximum working temperature. That should never be a problem on public roads at legal speeds so manufacturers don't bother.ChawenHalo said:
ChawenHalo said:
Is this the sort of thing you have in mind? :wink:
Liverpool
On my Z3 MC I have fixed some "fins" inside the front wheel arches, as shown in the photo below. The purpose of these is to reduce air turbulence within the wheel arches so that flow through the wheel arches occurs more readily. They act like "breakwaters" on the beach. These have been on my MC for about 5 years or so and I got the idea from reading a specific patent application. I intend to do something similar on my Z4MC but not yet got round to it.
It might be possible to use the Z4MC brake ducts to produce an "air curtain" as per the BMW 1M: http://www.bimmerfile.com/2010/12/13/the-1ms-air-curtain-in-detail/
Apparently, the 1M doesn't actually have any brake ducts. Perhaps the "air curtain" creates a Venturi Effect, expelling hot air from the brakes along the side of the car?
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Apparently, the 1M doesn't actually have any brake ducts. Perhaps the "air curtain" creates a Venturi Effect, expelling hot air from the brakes along the side of the car?
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mmm-five said:You need to fit a set of e34 M5 'Turbine' wheels (M-System I wheels) as the 3-piece design were meant to help cool the brakes.
MMM 5 you should be ashamed of taking the piss :x we're trying to find serious solutions and avoid AP BBK's and re-engineering our cars (WW2 was won by such creative make do you know).
Its great fun I'm loving it.
ChawenHalo said:
Is this the sort of thing you have in mind? :wink:
[/quote]:lol: yes if they ever did a 4x4 Defender beater!
more like this or a M6 style/ Aston Martin/ ACS Profile wing air expeller (not sure any of these actually do anything but would love to join form with function.
ChawenHalo said:more like this or a M6 style/ Aston Martin/ ACS Profile wing air expeller (not sure any of these actually do anything but would love to join form with function.
The Z4MC in full race trim is one of the best looking racecars ever although the paint job on that car could be better. Those ducts in the cill behind the front wheel should aid extraction of air from the wheel arches, which should reduce turbulence in the wheel arch, aid brake cooling and also act as a form of "air curtain" as a "side skirt" to prevent air going underneath the car.
ChawenHalo said:
I'm not ashamed, as I was serious, and I had them on one of my M5s.
They did away with that style on later models as they used the same wheel with a different cover to do a similar thing, and then did away with the concept completely when they decided to put 4-pot floating brakes and 343mm discs on.
mmm-five said:
Love old M5's although being a young prat my penchant is for the E39 5L V8. Sweet car. Discreet. Not such a fan of the recent shouty ones.
Where those spining wheels not on the NASCA or whatever the pebble smooth concept cart from BMW was. I would have thought it increased "unspruing" weight (I don't really know what that means TBH
BY 4 pots you mean they the 1 piston floating jobby is a recent thing? Not traditional BMW? Why did they do that?
Sorry thatv s a lot of questions.
exdos said:ChawenHalo said:more like this or a M6 style/ Aston Martin/ ACS Profile wing air expeller (not sure any of these actually do anything but would love to join form with function.
The Z4MC in full race trim is one of the best looking racecars ever although the paint job on that car could be better. Those ducts in the cill behind the front wheel should aid extraction of air from the wheel arches, which should reduce turbulence in the wheel arch, aid brake cooling and also act as a form of "air curtain" as a "side skirt" to prevent air going underneath the car.
Do you think we could do something like on our cars? Surely those arches are big enough to find an extraction slot that's not buggers and looks like something we find on Aston or Z8 or M6? (I have no idea whether thay are functional though). :?
I've presently got visible access to the insides of the bodywork at the front of my Z4MC and I think that there is a distinct possibility of being able to do an "air-curtain" mod. I'm trying to find the parts diagram and a few photos from the 1M and also get to know more about it and the precise function and advantages of the system. If the air-curtain assists in brake cooling, then on our cars, as road cars, I think this would be better than extraction slots behind the wheels.ChawenHalo said:
If all is required for an air-curtain, is for air to pass from the zone of high pressure at the front of the car and exit at the edge of the wheel arch in front of the wheel, then this could easily be achieved by drilling a series of small holes close to the edge of the wheel arch liner, because the vents at the top of the brake ducts already allow air into bumper area just in front of the wheel arch liner, and allowing it to escape through a series of holes in the liner should therefore produce an air-curtain.
The covers don't move independently of the wheel - they just draw air across the brake disc as the whole wheel/tyre rotates.ChawenHalo said:Where those spining wheels not on the NASCA or whatever the pebble smooth concept cart from BMW was. I would have thought it increased "unspruing" weight (I don't really know what that means TBH
BMW used to offer better brakes for their ///M models, but I assume that in the late 90's there was a bit of penny-pinching when they moved the ///M line into the main factory, and the ///M bit became almost purely a badge-engineering exercise.ChawenHalo said:
They may have learnt a lesson or two though as they're offering better brakes or brake upgrades for their 'performance' offerings now.
so then single piston floating items are pants?
BMW are really stupid in whoring out their ///M badge. Its really lost a lot of its shine.
Yes - but fine for most road uses. But why BMW thought £500 extra would matter to someone buying a £40k+ car is anyone's guess. Although probably means they can squeeze their supplier by another 0.0001% as they're buying 1% more of the same shitty item.ChawenHalo said: