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11-06-2012, 10:17 AM | #67 | |
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-The brakes function by converting the kinetic energy of the car into thermal energy during deceleration - producing heat, lots of heat - which must then be transferred into the surroundings and into the air stream. - The amount of heat produced in context with a brake system needs to be considered with reference to time meaning rate of work done or power. Looking at only one side of a front brake assembly, the rate of work done by stopping a 3500-pound car traveling at 100 Mph in eight seconds is 30,600 calories/sec or 437,100 BTU/hr or is equivalent to 128 kW or 172 Hp. The disc dissipates approximately 80% of this energy. The ratio of heat transfer among the three mechanisms is dependent on the operating temperature of the system. The primary difference being the increasing contribution of radiation as the temperature of the disc rises. The contribution of the conductive mechanism is also dependent on the mass of the disc and the attachment designs, with disc used for racecars being typically lower in mass and fixed by mechanism that are restrictive to conduction. At 1000oF the ratios on a racing 2-piece annular disc design are 10% conductive, 45% convective, 45% radiation. Similarly on a high performance street one-piece design, the ratios are 25% conductive, 25% convective, 50% radiation. -Repeated hard stops require both effective heat transfer and adequate thermal storage capacity within the disc. The more disc surface area per unit mass and the greater and more efficient the mass flow of air over and through the disc, the faster the heat will be dissipated and the more efficient the entire system will be. At the same time, the brake discs must have enough thermal storage capacity to prevent distortion and/or cracking from thermal stress until the heat can be dissipated. This is not particularly important in a single stop but it is crucial in the case of repeated stops from high speed |
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11-06-2012, 10:27 AM | #68 |
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BTW Gary, all this is said respectfully, it's just my understanding and not law by any measure.
I still stand by my opinion that from a performance stand point number of pistons is less important then rotor size and to your point, cooling. Then again,I bought my Brembo GT's 98% based only on bling. But they do perform well and look good. |
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11-06-2012, 10:31 AM | #69 |
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Just because you guys got me looking into my options, there's also Performance Friction apparently:
http://www.1addicts.com/forums/showthread.php?t=460211 Interesting 4 pads per disc design. One piece caliper. Looks like around 3600 front + 3500 rear? *sigh* |
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11-06-2012, 10:35 AM | #70 | |
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In the stock 135i calipers, having three small pistons instead of one or two big ones might actually be causing problems. We've seen evidence of some kind of uneven or incorrect piston pressure when the brakes are stressed, which the RacingBrakes guy said was a big cause of his rotors cracking in my car and FocusedIntention's car. |
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11-06-2012, 10:44 AM | #71 |
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I haven't heard that part before but it makes sense. So a heavier rotor can absorb more heat, but a lighter one the same diameter can dissipate heat faster.
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11-06-2012, 04:08 PM | #72 | ||
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Ie, it turns kinetic into heat faster is all It's simple more braking force, not cooling/heat dissipation. |
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11-06-2012, 04:28 PM | #73 |
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Avoid the cheaper set ups if possible, I've always used the brembo's and found them a stark contrast to other brands, particularly rotoras, as MTek said. Although, it's your decision, either way they are all a major improvement on stock
Edit: Well this turned out to be several more pages of text than I was expecting |
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11-07-2012, 12:54 PM | #74 | |
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Perhaps at a lower price point, I am awaiting a reply.
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128i Sport 6MT converted to Euro 130i spec, 3.73 diff, tuned by evolve ~220 whp 207 wtq(ft-lb) SAE
In-progress: //M front arm, M3 rack, e36M lip Wishlist: Coils, n55 mnts, headers, LSD, e60 finn diff "The 1-series is the last car that BMW engineered before the Germans, as a car-making culture, fell out of love with driving." - R&T 2013 135is Last edited by andrey_gta; 11-07-2012 at 01:39 PM.. |
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11-07-2012, 01:25 PM | #75 | |
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Couldn't find a price on their site. Any US Powerbrake dealers? |
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11-15-2012, 07:45 PM | #76 |
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Location: Santa Barbara, AP, Brembo, GIAC, Koni, Ohlins, Performance Friction, www.hpautosport.com
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11-16-2012, 03:33 PM | #77 | |
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11-16-2012, 05:52 PM | #78 | |
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03-03-2013, 01:14 PM | #79 |
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Hi Gents,
This is my first post! I was really surprised to find POWERBRAKE mentioned on this forum. I owned the company in South Africa called FORZA Racing, we specialized in Ferrari's and more importantly Ferrari Racing. We tied up with POWERBRAKE to develop a BBK kit for our F430 CHALLENGE clients. These cars came with the CCM brembo system and due to cost and reliabilty the CCM option was not viable. In conjunction with Clive at POWERBRAKE we developed the 6 piston caliper and 350x35( I think) disc system. The results were MIND BLOWING!!! The POWERBRAKE system out performed the Brembo CCM in all aspects but most importantly the cost saving was just astounding!!! The brakes had way better feel/feed back on the pedal. The stopper power was definitely up. We tested many pads including Hawk CARBOTEC and eventually we settled on ENDLESS PADS. I know most people in the "civilized world" couldn't imagine a small company at the tip of Africa could develop a BBK that can compete with The likes of Brembo/AP/Alcon etc but I can say I have raced on all these brands and POWERBRAKE is as good if not better in certain aspects. PS: I now work for BMW dealer as the SErvice Manager and I just bought myself a brand new 135 N55! |
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03-03-2013, 02:02 PM | #80 | |
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Unfortunately, they did not reply to my 3 basic inquiries via their email, SA website, or USA website. Its unfortunate, but I guess their local market is more of a priority. Perhaps you can contact them on behalf of BMW e82 135i and inquire into their options, shipping cots and such.
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128i Sport 6MT converted to Euro 130i spec, 3.73 diff, tuned by evolve ~220 whp 207 wtq(ft-lb) SAE
In-progress: //M front arm, M3 rack, e36M lip Wishlist: Coils, n55 mnts, headers, LSD, e60 finn diff "The 1-series is the last car that BMW engineered before the Germans, as a car-making culture, fell out of love with driving." - R&T 2013 135is Last edited by andrey_gta; 03-03-2013 at 03:16 PM.. |
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03-04-2013, 01:10 PM | #81 |
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[QUOTE=Unfortunately, they did not reply to my 3 basic inquiries via their email, SA website, or USA website. Its unfortunate, but I guess their local market is more of a priority. Perhaps you can contact them on behalf of BMW e82 135i and inquire into their options, shipping cots and such.[/QUOTE]
Spoke to Clive at POWERBRAKE about your post. They should be in contact with you ASAP!!! Not to speak on POWERBRAKE's behalf but I think what they are experiencing is what happens to many small niche companies on the verge of taking the next major step with regards growth... They have just grown to quickly to keep up with demand I guess. I know the DAKAR RALLY was a massive project for them And my guess is your enquiries probably came through when they were meeting the deadlines for TOYOTA MOTORSPORT. what I can tell you is that i'm definitely gonna do a POWERBRAKE BBK... But first I'm gonna do the M suspension then JB4 stage 2 with FMIC, DP, INTAKE, WATER METH, OCC... |
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03-04-2013, 04:52 PM | #82 |
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this is coming of waaaayyy like an adertisement, with the highlighting of events the powerbrakes have been used in haha
could well be enthusiasm though :P |
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03-04-2013, 10:42 PM | #83 | |
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Definately enthusiasm... Last edited by OscarDeo; 03-05-2013 at 11:05 AM.. |
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02-04-2020, 05:01 AM | #84 |
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I know its an old thread but I'm curious whos been running what BBK? And I'm also curious if anyone has fit 380mm rotors on 18" wheels. I don't quite understand why theres a huge gap between certain BBK brands in terms of price. Ive seen several (willwood, yellow speed racing) around the 2k range and others (Brembo, stoptech, Sparta, etc) between 3k-6k+. /shrug
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09-07-2020, 12:00 PM | #85 | |
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hopefully they clear the barrel, then at worst it's a matter of spacers. i know SOME 18's will clear 380mm barrel-wise, fine. The F80 brake setup specifically is pretty cheap, on the lower end, but the rest of fitting it, is not (m3 knuckles, shocks to suit, booster etc.) but it's also on the heavy end, big heavy cast calipers, unlike some of the lighter forged race spec stuff on offer. that's probably the main difference when you're spending the big money. |
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09-07-2020, 08:38 PM | #86 | |
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Currently my plan when I finally decide to abandon my stock brembos. Does the rear F8x bbk fit though? The rear brakes are a pretty big limiting factor in changing if you don't want to totally throw off bias.
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09-08-2020, 07:47 AM | #87 | |
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but i've got E90 M3 rear knuckles also and F80 hubs so will bolt up |
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10-13-2020, 02:30 PM | #88 | |
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An F8X brake front and rear conversion has been done by a member of the UK forum. I don't have too many details though unfortunately. He created a rear bracket for the rears to fit. [IMG]https://www.mupload.nl/img/4z7kbzl02cpt.jpg[/IMG] [IMG]https://www.mupload.nl/img/e1c79vzwt.jpg[/IMG] [IMG]https://www.mupload.nl/img/3hrnmy.jpg[/IMG] [IMG]https://www.mupload.nl/img/gkkjys.jpg[/IMG] [IMG]https://www.mupload.nl/img/cd4y3z09.jpg[/IMG] |
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