[uucdigest] Thursday, September 18 2003 Volume 03 : Number 6765
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Send 'em to [EMAIL PROTECTED] |__________________________________________________________________ In this BMW UUC Digest: RE: [uuc] Minimum Brake Pad Thicknesses for Track Usage Re: [uuc] Kumho MX tire RE: [uuc] Kumho MX tire RE: [uuc] Minimum Brake Pad Thicknesses for Track Usage [uuc] Re: [E36 M3] Cam install Re: [uuc] Brakes at the track Re: [uuc] Brakes at the track Re: [uuc] Minimum Brake Pad Thicknesses for Track Usage Re: [uuc] Brakes at the track RE: [uuc] <e36> UUC Stage II Flywheel + M5 Clutch + USSE3 ? ---------------------------------------------------------------------- Date: Thu, 18 Sep 2003 14:59:40 -0700 From: "Marco Romani" <[EMAIL PROTECTED]> Subject: RE: [uuc] Minimum Brake Pad Thicknesses for Track Usage Alex, I was told that it was possible by a former BMW mechanic that races an E36. I've rebuilt many a caliper, thanks. However, I've never bothered to do the math on if the rotor is at minimum run out and the pads are gone if the cyclinder can get to the point where it will leak. I didn't say the cylinder will fall out and go shooting across the track. ;-) Next time I have everything apart I'll measure it. never-the-less pads are cheap. Track time is expensive. Why get to the point where you may have to loose track time to save a few bucks on pads? I have seen some guys run the backing plates down so far that they were about 1/2 normal thickness. Amazing. Marco - -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Thursday, September 18, 2003 1:50 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: RE: [uuc] Minimum Brake Pad Thicknesses for Track Usage "Marco Romani" <[EMAIL PROTECTED]> wrote: > One thing you don't want to happen is to have the pad material wear > down so far that the pistons extends so far resulting in a fluid leak > and then a brake fire. Marco, I don't think that can physically happen! Under the worst of circumstances, the pad will wear to the backing plate and the latter will start scarring the rotor. The backing plate does not have anywhere near the coefficient of friction of the brake pad material, but it will still slow down the car. If you've ever rebuild the calipers, you know that the caliper piston is very long. It can probably push all the way through the backing plate and come in contact with the rotor and still keep the brake system properly sealed. What does frequently happen when you are finishing off old pads, is that caliper outer rubber dust seals extend out more than usual. If it's old and, the seal are likely to either crack or dislodge from the groove on the piston. The only way to set it back in place is to rebuild the calipers. A straight forward, inexpensive, 15 minute/caliper, but somewhat messy exercise. Otherwise I agree entirely with Chris P. If this is your first school, make sure you have at least 50% of the pad material. While you are unlikely to wear it off as you wont be going that fast, you really don't want to worry about your brakes during your first DE. alex ------------------------------ Date: Thu, 18 Sep 2003 18:04:14 -0400 From: "Eurowerks" <[EMAIL PROTECTED]> Subject: Re: [uuc] Kumho MX tire Fantastic experience with a client's 325iS. Low noise, exceptional wet and dry and CHEAP! Kirk A. Gilchrist EURO-WERKS / Mercedes-Benz, BMW, Volvo Service and Repair 8 South Highland St. / Winchester, KY 40391 / 859-745-0125 [EMAIL PROTECTED] / 888-522-0271 toll free ------------------------------ Date: Thu, 18 Sep 2003 17:16:46 -0500 From: "Jamie Howton" <[EMAIL PROTECTED]> Subject: RE: [uuc] Kumho MX tire > Any experiences with the new Kumho MX tire? > Is it the value it appears to be? My $0.02 I have almost 10K miles on a set of 225/40-18 Kuhmo MX's on my 95 M3 with one Road America D/E and two Autocrosses on them. Current tread depth is approx .15" pretty evenly across all four tires, I rotate front to back about every 4K miles. I don't remember what the tread depth was when new. My car is lowered on the TC Kline Trackline suspension (H&R track and Koni S/A) with solid rear shock mounts, spherical rear trailing arm bushings and Solid front control arm bushings (all Control Tech). It is aligned as close to stock toe settings as possible although I have no numbers with me. In dry summer weather they grip very well, I have no experience with race rubber but these are among the best street tires I have driven on. They tramline quite a bit on Chicago area highways, but some of the roads are pretty rutted so I am not surprised. In the wet they give up some traction, it's much easier to get sideways and taking off from a stoplight and requires some feathering of the accelerator (my engine is not stock FWIW). They are not as good as SO3's in wet conditions although I haven't felt any evidence of hydroplaning at very fast highway speeds. I haven't tried them below 50 degrees F, so I have no idea how they would do in winter, my guess is "not well". I probably would buy these tires again although I'd go with a 235 or 245 width next time, they'd fit which is contrary to the advice that I got from the Tire Rack. Regards Jamie Howton 2002 330i 1995 M3 ------------------------------ Date: Thu, 18 Sep 2003 15:20:53 -0700 From: "Marco Romani" <[EMAIL PROTECTED]> Subject: RE: [uuc] Minimum Brake Pad Thicknesses for Track Usage Kim, thanks. I stand corrected. Marco I think I've done maybe 40 caliper rebuilds in my life ;-) - -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Kim Henshaw Sent: Thursday, September 18, 2003 2:48 PM To: [EMAIL PROTECTED] Subject: RE: [uuc] Minimum Brake Pad Thicknesses for Track Usage You're both almost right....... The most common cause of leaking calipers we see (we do around 100 brake repairs a month) is age related deterioration of the piston seals or rust pitting of the piston itself caused by infrequent fluid changes. However, we do see some that are caused by the pads being so worn down that the piston moves onto an area of the caliper bore that either has a build up of sludge or some rust pitting. This causes small tears in the seals and the fluid leaks out. While not common, it does happen and seems much more likely when the disc rotor is also worn substantially. FWIW Kim Henshaw PS : This is the same problem that often occurs at the master cylinder when bleeding brakes in the traditional "push the pedal to the floor while I open/close the nipple" manner. - -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Friday, September 19, 2003 6:50 AM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: RE: [uuc] Minimum Brake Pad Thicknesses for Track Usage "Marco Romani" <[EMAIL PROTECTED]> wrote: > One thing you don't want to happen is to have the pad material wear > down so far that the pistons extends so far resulting in a fluid leak > and then a brake fire. Marco, I don't think that can physically happen! Under the worst of circumstances, the pad will wear to the backing plate and the latter will start scarring the rotor. The backing plate does not have anywhere near the coefficient of friction of the brake pad material, but it will still slow down the car. If you've ever rebuild the calipers, you know that the caliper piston is very long. It can probably push all the way through the backing plate and come in contact with the rotor and still keep the brake system properly sealed. What does frequently happen when you are finishing off old pads, is that caliper outer rubber dust seals extend out more than usual. If it's old and, the seal are likely to either crack or dislodge from the groove on the piston. The only way to set it back in place is to rebuild the calipers. A straight forward, inexpensive, 15 minute/caliper, but somewhat messy exercise. Otherwise I agree entirely with Chris P. If this is your first school, make sure you have at least 50% of the pad material. While you are unlikely to wear it off as you wont be going that fast, you really don't want to worry about your brakes during your first DE. alex ------------------------------ Date: Thu, 18 Sep 2003 17:25:17 -0500 From: Neil Maller <[EMAIL PROTECTED]> Subject: [uuc] Re: [E36 M3] Cam install on 9/18/03 10:17 AM, Andrew E. Skopp at [EMAIL PROTECTED] wrote: > So, can you describe the driving differences between the two? Essentially unchanged at low revs. For instance you can still pull away from just above idle in 3rd around a low speed turn, just like stock. There's noticeably greater urgency above 4K rpm, and a bunch more from 5K to max revs. The extra power is very smooth. Frankly it feels factory, to the point where you ask yourself why the factory didn't do it in the first place. If you've driven a 95 M3 you'll know that it revs much more freely than a stock 96+. With the cam kit the OBD-II engine is no longer constrained at higher rpm, and feels more like a 95, but with more torque due to its bigger engine. Since the improvement is at higher rpm it's something I notice more in track use than in daily use on the street. Neil 96 M3 ------------------------------ Date: Thu, 18 Sep 2003 16:12:24 -0700 From: Bora Akyol (BMW) <[EMAIL PROTECTED]> Subject: Re: [uuc] Brakes at the track It takes me about 10 minutes to swap pads, and 15 to do the rotors. But I think it is a GREAT idea to start a track event with relatively new pads. Unless you are running with expensive racing pads (like PF9X), it is not worth the hassle. Bora On Thursday, Sep 18, 2003, at 14:39 US/Pacific, Dave Nichols wrote: > I agree that you can run the pads down fairly thin as long as you have > adequate cooling, but one of the biggest factors in changing pads at > the track is the PITA factor.� If you have a set of Brembos and only > need to remove two pins to slide out the pads, you can change 'em in > about 2 minutes per wheel.� If you have to take the caliper off, > compress the piston, put the pads in and put it all back together, why > bother, just put in some new ones before the event and have some fun. > � > My $.02 > � > Big Dog > > > Dave Nichols ------------------------------ Date: Thu, 18 Sep 2003 16:50:51 -0700 (PDT) From: willie yeo <[EMAIL PROTECTED]> Subject: Re: [uuc] Brakes at the track I find changing pads easy but it is PITA to jack up the car and take off the wheels to facilicate the swap. Especially you do not own power tools and changing them in a 90 degree day on paved asphalt parking lot. Gingerman raceway is one of them. Will - --- Dave Nichols <[EMAIL PROTECTED]> wrote: > I agree that you can run the pads down fairly thin > as long as you have adequate cooling, but one of the > biggest factors in changing pads at the track is the > PITA factor. If you have a set of Brembos and only > need to remove two pins to slide out the pads, you > can change 'em in about 2 minutes per wheel. If you > have to take the caliper off, compress the piston, > put the pads in and put it all back together, why > bother, just put in some new ones before the event > and have some fun. > > My $.02 > > Big Dog > > > Dave Nichols __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com ------------------------------ Date: Thu, 18 Sep 2003 19:19:34 -0400 From: "Gary Derian" <[EMAIL PROTECTED]> Subject: Re: [uuc] Minimum Brake Pad Thicknesses for Track Usage Steel on iron has a mu of about 0.2. Brakes pads about 0.4. Gary Derian > and the latter will start scarring the rotor. The backing plate does not > have anywhere near the coefficient of friction of the brake pad material, > but it will still slow down the car. ------------------------------ Date: Thu, 18 Sep 2003 17:34:47 -0700 From: Bora Akyol (BMW) <[EMAIL PROTECTED]> Subject: Re: [uuc] Brakes at the track Try repairing a broken power steering hose with hot fluid dripping on your body. Or you can do what I did and just cut the damn belt and never look back :-) On Thursday, Sep 18, 2003, at 16:50 US/Pacific, willie yeo wrote: > I find changing pads easy but it is PITA to jack up > the car and take off the wheels to facilicate the > swap. > > Especially you do not own power tools and changing > them in a 90 degree day on paved asphalt parking lot. > Gingerman raceway is one of them. > > Will > ------------------------------ Date: Thu, 18 Sep 2003 19:11:49 -0700 From: "Clan Hood-Douda" <[EMAIL PROTECTED]> Subject: RE: [uuc] <e36> UUC Stage II Flywheel + M5 Clutch + USSE3 ? Are you saying that the flex disk is responsible for the apparent clutch action? Or just reminding me to change it while I'm in there? I planned on changing it as part of the service. Mike - -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gary Derian Sent: Thursday, September 18, 2003 8:56 AM To: [EMAIL PROTECTED] Subject: Re: [uuc] <e36> UUC Stage II Flywheel + M5 Clutch + USSE3 ? Flex disk. Gary Derian > After the last round of cooling system and suspension refurbishing, > next up > is the original clutch and dual-mass flywheel in our '95 325i. At 123K > miles, the clutch is exhibiting hot "judders" or rough take up from a > standing start. No slipping is evident, but the behavior makes it difficult > to drive smoothly in traffic. ------------------------------ End of [uucdigest] V3 #6765 *************************** | | In memory of Michel Potheau - friend, enthusiast, founder of the BMW CCA. |________________________________________ | Please visit these UUC-approved BMW parts vendors/service providers: | (listed alphabetically) | | Autoscope-Motorsports - http://www.autoscope-motorsports.com | |==================================================== | | Koala MotorSport . BMW technical information, special tool sales/rental | http://www.koalamotorsport.com | |==================================================== | | Taylor BMW - http://www.taylorbmw.com - Doc Bimmer! | |==================================================== | Turner Motorsport Inc . 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