Our hillclimb Rabbit has a braking system without a booster, as it was removed some years ago to accomodate the linkage for a custom pedestal gearshift arrangement. At that time a 17mm master cylinder from a very early Rabbit (unboosted as stock, I believe-?) was installed. This provided adequate braking, but with a very mushy feel. (Soft pedals in Rabbits appeared to be more usual than not when I was racing a GTI in ITB some years ago.) We just finished the installation of a new 21mm master cylinder to try to get a firmer pedal. That goal has been resoundingly met, but I can no longer lock the brakes, which is not acceptable. My question to the forum is: are there master cylinders of, say, 18-19mm available for or adaptable to Rabbits? We have rear disc brakes from a later model; they are fed through individual lines with a master cylinder mounted VW proportioning valve for each line. The cylinder has an outlet hole for each wheel.

My calculations indicate that the 21mm has about 60% of the mechanical advanatage of the 17mm. My guess is that halving that reduction to c. 80% could result in a good stopping, firm pedalled car.
6 X 13 (or 6.5 X 13) wheels, with stock offset. I'm told that VW did not make them. Did anyone? We're in the market, particularly used.

Thanks-

Don Peaslee
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Don,

I'm a bit confused. You put rear discs (I assume off a 16v car) on your Rabbit. You also used the 16v (21mm) master cylinder, and the associated prop. valve (I assume you used the larger prop valve). While you may have increased pedal effort, you have the large MC, so you should still be able to lock the brakes. I assume you've put on stainless brake lines.

Something you may want to look at are your calipers. You may have issues w/ the seals leaking, and not applying the full clamping force. That's probably where I'd look first.

As far as 13x6 (actually, anything wider than 13x5.5) go, nothing OEM from VWoA (might be some from Europe, but I've never heard of any in over 20 years in the VW watercooled scene). There were several choices back in the 80's (BBS, Rial, Enkei, MSW, Ronal, ATS, etc.), but nothing that's probably less than 10 years old. You can get race wheels like Panasport, Joengblood, etc. made, but they're pretty pricey. An alternative are steel wheels from Diamond. You can get wider widths too. The price you pay, is that they're not light. Not only that, you need what's known as a torque plate for VW hubs.