08-04-2003, 09:55 PM
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Registered User
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Join Date: May 2003
Posts: 532
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 Quote:
Originally posted by papajam
My limited knowledge in brake hydraulic design tells me that if the total wet area of the pistons in the 4 pot calipers is greater than that of the 2 pot ATEs, then pedal effort will actually decrease. With more pedal travel though.
What model Bimmer did the calipers come from? And do you know the piston diameter?
Loosing the weight of two high mounted boosters certainly won't hurt the handling either!
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Hi Jim:
The 4-pot Ate's are front calipers from a '72-'74 2002tii, although similar calipers were used on 528i's, and early 630CSi's, before BMW changed to vented front rotors. The calipers bolt on to a 105/115 that had the smaller Ate brakes as OEM, but require a split hard line, as the tii calipers have 2 fluid inlets. Here's a link to the AROO article that turned me on to the setup, and note Jim Steck was involved:
http://alfaclub.org/techstff/brkupgd.htm
Last summer, before I did the upgrade on my '74 Spider, I heard from Mike Brann (the article's co-author), who said he's still happy with his brakes after nearly 10 years. I'm also using a stock 22mm MC, and with the EBC Green Kevlar pads, the system works extremely well.
I also thought about using the calipers from a BMW 733i, with vented Montreal rotors, but it just wasn't necessary. As an ex-BMW guy, I called a few parts wholesalers I knew and found one that sold me 16 sets of the tii calipers for $160/set (no core charges) and I divvied them up among some of the Alfa Digest group, and also kept an extra set which will go on my '87 Spider.
Mike Valant has been trying the Outlaw calipers on one of his race cars, but the last I heard, he was having balance problems.
http://mev4474.home.texas.net/index.htm
The Outlaw's are reasonably priced, though, and are available with custom-sized pistons, so they are a viable option. Andy Kress has been selling them for Alfa apps:
http://www.performatek.com/frOnlineCatalog.htm
Anyway, for street use, I'm more than happy with the tii brakes, and the price wasn't very high for the upgrade. In fact, they were cheaper than the rebuilt original calipers I needed anyway. The wholesaler I bought them from had some calipers left last Summer, but I've not asked since then. If you want me to inquire, let me know. There's a pic attached, but sorry I've never taken any of the calipers installed on the Spider.
Regards,
Dean
Last edited by dwc; 08-04-2003 at 09:58 PM.
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