[uucdigest] Tuesday, March 21 2000 Volume 03 : Number 481 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | For all available Digest commands including unsubscribe/subscribe, | visit the BMW UUC Digest page: http://www.uucdigest.com | Send SUBMISSIONS to [EMAIL PROTECTED] | Complaints? Send 'em to [EMAIL PROTECTED] if you must. | Visit http://www.bubbaclub.com | www.bimmers.com - "serving enthusiasts on the 'net" | Visit http://www.bimmer.org - ultimate BMW bulletin boards! | Subscribe to the Zionsville Autosport Parts Digest: | http://www.zionsvilleautosport.com/majordomo.htm ����������������������������������������� In this BMW UUC Digest: Re: [uuc] E30 Twin Cam Conversion on CD-ROM [uuc] Re: [MISC] Cryogenic treatment for brake rotors -- snake oil, or not? [uuc] <E36> Strange buzzer [uuc] <wob> Girl Scout Cookies Re: [uuc] Cryogenic treatment for brake rotors -- snake oil, or not? [uuc] X5 BAJA? ---------------------------------------------------------------------- Date: Tue, 21 Mar 2000 00:23:26 EST From: [EMAIL PROTECTED] Subject: Re: [uuc] E30 Twin Cam Conversion on CD-ROM Jason, What is the target price for the CD? paul In a message dated 3/20/00 9:54:51 AM Pacific Standard Time, [EMAIL PROTECTED] writes: << [EMAIL PROTECTED] >> ------------------------------ Date: Mon, 20 Mar 2000 21:26:32 -0800 From: Knute Ream <[EMAIL PROTECTED]> Subject: [uuc] Re: [MISC] Cryogenic treatment for brake rotors -- snake oil, or not? I commented on this once before a year or two ago, so those who read my babbling the first time, please forgive the repeat! At least this time I provided a website with references... I work in the precision metal fabrication industry, and we pay very close attention to anything that will increase the life span of expensive punch tooling. On a turret punch press, for example, a typical tool might be subjected to ~30 tons of pressure, and punch up to 100,000 hits or so between sharpenings. In this environment, hardness is only one of the factors that increases the life of the tool; it is also VERY important to not have "voids" in the crystalline structure of the tool steel (voids can propagate stress fractures) and also VERY important to avoid any internal stresses in the metal (dimensional stability). For those new to the concept, "internal stresses" means that some of the metal in the part really wants to be a different shape than the metal around it. When the metal heats up, particularly if the metal is heated unevenly (i.e. different temperatures at different locations on the metal) these internal stresses can change the dimensions of the metal part. (This is a bad thing) So what does all this have to do with brake rotors? Simple. Cryogenically treated parts tend to have fewer voids in the structure, and tend to have reduced internal stresses. This makes the punches last longer (in my example above; as much as double the life or more) and for brake rotors, reduces both the rate of wear and also the tendency for the rotors to warp like a pretzel when heated. My own empirical evidence is limited to tooling applications, but the effect is real and logically applies well to brakes. Note: cryogenic treatment does not simply mean that the parts were frozen. It means (if done correctly) that they were chilled at a measured rate with an even gradient across the part to a target temperature, were held at the target temperature for a specified time, and then were warmed back up to room temperature at a measured rate, again preserving an even temperature gradient. The colder the temperature, the more the effect, and it is my understanding that it forces the micro-structure of the steel to adopt a more uniform arrangement. Anyone really interested in learning the ins and outs of austenite and martensite structures, copious references, a history of blacksmithing, etc. can find a good read at: http://ccwf.cc.utexas.edu/~jwgary/cryo/ Regards, - -Knute At 06:36 PM 3/20/00 -0500, Gleb Arshinov <[EMAIL PROTECTED]> wrote: >Subject: [uuc] Cryogenic treatment for brake rotors -- snake oil, or not? > >So, I always thought this process was BS [...snip...] >Now, I've learned that local track buddies (Hi Jim & Donna :-), sane >enough looking people (hehe), are cryo-treating their rotors. Being >an open-minded person, I tried to find some evidence of cryo benefits >on the Net. I failed. All that I saw was pseudo-science description >of the process by vendor and multiple "testimonials".[... snip ...] >So, is anyone aware of any evidence, for or against the process? I am >thinking either proper scientific study published in some SAE journal, >or, perhaps, material science journal. [...snip...] ------------------------------ Date: Mon, 20 Mar 2000 21:49:02 -0800 From: Avinash Heroor <[EMAIL PROTECTED]> Subject: [uuc] <E36> Strange buzzer The other day, I turned on the hazard warning lights on my '92 325 E36 and got out of the car without switching off my headlights. The warning buzzer wound up sounding/not sounding in synchronization with the hazard flash! Questions : 1. Is this normal? 2 If the answer to 1 is "NO", what is going to/has already failed? Thanks, - --Avi ------------------------------ Date: Mon, 20 Mar 2000 22:21:35 -0800 From: Scott D Miller <[EMAIL PROTECTED]> Subject: [uuc] <wob> Girl Scout Cookies This is a follow-up to last week's exchanges between me, Jim Ochi, John Bolhuis and others. Go find the messages if you've already forgotten about it. I said something like: We've got a guy destroying cars on test drives and another guy dreaming about being nekkid and having women throw small pickles at him, and yet other guys tearing up school yards turning donuts on the grass. What next, I wondered, someone stealing cookies from the Girs Scouts? Then Bolhuis accused Ochi of doing that. Then Ochi explained how he backed his car, with open trunk, into the flimsy card table with the cookies on it, and the table was punted and the cookies landed in his trunk and he took off. And this all seemed like good fun at the time, but I said that if Ochi showed up at the GGC autocross with Girl Scout cookies, I was calling the cops. And I thought I was joking. So I was pre-running the course to be sure the cones were in the right place, and I got out of the car for a minute to move cones around, and when I returned to my car, there were about 10 boxes of Girl Scout cookies in the front seat. I did not call the cops. I'm not sure if this was done by Ochi the dispicable GS cookie thief, or by Bolhuis in an effort to frame Ochi for a crime he did not commit. Investigation is ongoing. Oh, and the FTD was set by Navid Kahangi (sp?), who wins all kinds of SCCA autocross awards, but who was driving someone else's car. The only Audi present was an A6 with about 1500 miles on the clock. No sign of the S4 this time. Scott Miller GGC BMW CCA #44977 GGC Autocross Coordinator Dude with GS cookies up the wazoo ------------------------------ Date: Tue, 21 Mar 2000 01:24:40 EST From: [EMAIL PROTECTED] Subject: Re: [uuc] Cryogenic treatment for brake rotors -- snake oil, or not? Military personnel claim that tests with machine-guns show barrel life greatly extended by the treatment. Hundreds of top flight target shooters are having their best shooting target barrels treated due to the proven extended life. Machine gun barrels get very hot and I think that they would react similarly to break rotors but I'm not sure about warping. It wouldn't pay if the thing is going to warp anyway, even if it lasts longer. Your local public library can get you the articles. ------------------------------ Date: Tue, 21 Mar 2000 01:57:21 EST From: [EMAIL PROTECTED] Subject: [uuc] X5 BAJA? After watching the reviews of the Paris Dakar rally on speed vision and I was just thinking to myself how cool it would be to see the X5 attempt this. I know that is not what this vehicle was meant for, but to see an off road version with maybe the M5 power plant would be really cool. Brian Jacobs 98 318ti 99 Z3 coupe Everglades CCA [EMAIL PROTECTED] ------------------------------ End of [uucdigest] V3 #481 ************************** _________________________________________ | Please visit these UUC-approved BMW parts vendors/service providers: | (listed alphabetically) | Bonneville Motorwerks . http://www.bonnevillemotorwerks.com | Circle Tire Co. (used & classic BMW parts) e-mail [EMAIL PROTECTED] | Curry's Auto Service . http://www.currysauto.com | Eurosport . http://www.eurosport-hp.com | Koala MotorSport . http://www.koalamotorsport.com | Taylor BMW - http://www.taylorbmw.com - Doc Bimmer! | The Ultimate Garage . http://www.ultimategarage.com | UUC Motorwerks . http://www.uucmotorwerks.com | Zionsville Autosport . http://www.zionsvilleautosport.com ����������������������������������������
