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Discussion Starter #1
I am building an Alfa GTV 2000, 1974, and intend using it for hillclimbs, historic racing and road use. I have been advised by another racer to remove the brake boosters. Comments please?
 

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Peter,

Before you remove it, try driving it with the vacuum line disconnected.

I had a spider whose booster went out, and it required lots of pedal to stop. In fact my right
leg was sore after every drive. The difference
is very noticable.

Why do they recommend removing the booster?
I have seen guys put in their racers manual
brake bias, to adjust the amount of braking
from front to back.

Check this web site http://www.MEV.cc/
 

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My brake booster was out for a while and it was a good workout to stop the car('74 GTV). I wouldn't take it out for nothing.
Why would he say taking it out was a good thing? Is he in your will?
 

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Hi Peter,
Since you say boosters (plural), would your '74 be a RHD with standing pedals? If so, yes they can be removed with only a moderate increase in pedal pressure. Even if you find the pedal effort too high, fabricating a bracket to lower the pushrod end of the master and extending the brake pedal slightly will increase the pedal ratio resulting in less pedal effort but at the expense of slightly more pedal travel.
 

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Jim, Good call! Peter, South Africa is RHD, right?

I've driven a '69 Spider where the boosters went out, and while the effort was high, it was not nearly has bad as the hanging pedal design w/o the booster.

So if this IS a floor pedal car, you might be able to do it. Can still experiement with the vac lines....

Eric
 

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"Why would he say taking it out was a good thing? Is he in your will?"


Bwaahaa haa haa haa!!! Man I just spit coffee all
over my monitor. Kingpin, thanks for the morning laugh.:D
 

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Discussion Starter #7
Yes, the car is RHD and has floor mounted pedals. I can't try driving with the vac pipe off, as I'm still building the car. ( another couple of weeks) The car without boosters has BMW 4 pot front calipers, and EBC pads. The reason for running without the boosters is that he feels they are not needed with the larger calipers, and booster kits are hard to find here anyway. My car was bought as scrap, and only had a booster on the front brakes, so if I run boosters, I would have to source another one.
 

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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!:D
 

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Brakes

Peter.

Laurie from Alfa Clinic in JHB have always been able to supply me booster kits and I am sure he has some boosters stached away as well, give him a call, his number is 011 614 8918 or even speak to Leo - they are great for advise and help!

Paul.
 

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papajam said:
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!:D

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
 

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Thanks for the info Dean! Looks like another future project to add to the list.:D
Has anyone done this caliper conversion on a '69 US version Alfa with the stock, tandem circuit, 22mm ATE master cylinder?
 
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