Some of you know that I've considered swapping out the rear drums on my car for disks, even though most folks have told me that it's not really worth the extra expense unless you have serious power. I wouldn't listen because I am particularly inept at adjusting the drums, and I think the rear brakes aren't doing their share. Finally, I bought the whole kit and kaboodle from Carey that he uses when a customer wants rear disks.
Well, as often is the case, things didn't go as planned with some fitment issues that prevent my from using the disks with my exhaust. I won't bore everyone with the story, but I have my drums back and are quite happy with them because of what I will detail below. Carey is going to buy the majority of the kit back from me. I say majority, because seals and gaskets were used, and part of the kit included a new master cylinder meant for 4-wheel disks. I kept that MC, which is the point of this (long winded) post.
The new MC has a 20.5mm bore compared to the 19mm bore of the stock unit. That makes the braking effort a bit higher, but the feel is MUCH better. It's more progressive and easier to modulate to avoid locking the front wheels. Ken, my VW mechanic friend who helped me with the attempted install suggested that I use larger wheel cylinders on the rear brakes to bias the braking force a bit toward the rear, which I think the car needs, although not as badly as before. Ok, here's the question that you were wondering if I would ever get to: The stock wheel cylinders are 17mm, but larger ones are available. Is there a way to calculate an optimum size, and if so, what is it?
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