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Rear disc brakes
Ninehigh - 4/10/08 at 11:25 PM

The donor car is going to have front disc brakes, but I'd like rear ones too. Is it possible to convert drum brakes to disc brakes on the wheel hub or should I buy a totally separate set?

blakep82 - 5/10/08 at 12:04 AM

what is the donor?

Ninehigh - 5/10/08 at 12:06 AM

Nothing definite yet but something like a Fiesta, Pug 106 that kind of thing. Some small car with a 1-1.3l engine. Most likely it's going to have rear drum brakes and if it's too much of a pain in the rear then I'll stick to them as they'll be good enough

snapper - 5/10/08 at 06:45 AM

If you are building light then the drums will be more than enough, if you go rear discs you will need some form of brake bias control otherwise you may lock up the rears first.
If you pick a donor with rear drums and want rear discs make sure that there is a car in the range i.e a GTI version that has rear discs then its an easy job to swap parts.

philw - 5/10/08 at 09:00 AM

You say you are building a 2 seater sports car, with a Pug or Fiesta donor, so it will be front wheel drive then?

02GF74 - 5/10/08 at 09:03 AM

what is the obsession with rear disc brakes??

any partucular reason you feel you must have them?

what do you think is going to be wrong with having drums?

remember your car will be 1/2 the weight of the donor, depending on donor, whcih equates to a lot less mass to stop.

somone here has done the weighing and drums, as on escort mk2 are lighter than discs.

plus there is no messing about with bias bars, no messing around with handbrake mechanism plus no need for brackets to do the drum -> disc conversion.

anyways, it is up to you.

... but general question - anyone on here had car with both fitted, (not at same time obviously!) and can say that drums were inadequate? if so, how? just curious.

Ninehigh - 5/10/08 at 11:47 AM

Disc brakes give more stopping power than drum ones.. No obsession, just desire the maximum ability to stop that's possible.
The engine's going behind the seats, and I figured brake bias is naturally done in the size of the disc (mondeo back ones are much smaller than the front) then again if they're only going to cause more problems than they solve then I shan't bother..

rusty nuts - 5/10/08 at 11:52 AM

Try looking at the rear discs on something like a Porsche Boxster from under the car .9 times out of 10 the inner surfaces are pretty badly pitted because they are not doing a great deal of work . So ask yourself if they are really needed?

Ninehigh - 5/10/08 at 11:59 AM

Sounds like a rhetoric question. If they're not needed on a boxter then I won't need them hehe.

britishtrident - 6/10/08 at 04:10 PM

quote:
Originally posted by Ninehigh
Disc brakes give more stopping power than drum ones.. No obsession, just desire the maximum ability to stop that's possible.
The engine's going behind the seats, and I figured brake bias is naturally done in the size of the disc (mondeo back ones are much smaller than the front) then again if they're only going to cause more problems than they solve then I shan't bother..


Actually they don't give more power , the advantage of discs is fad resistance and feel ----- but if you are building a midi you need rear brakes that are only only very slightly smaller than the front brakes, you also need a proper handbrake.

On a midi the rear brakes need to do about 40 to 50 % of the stopping effort.

So you need rear calipers and discs off either fairly big RWD car or a midi ie Sierra or better still an MGF or MG-TF

[Edited on 6/10/08 by britishtrident]

Ninehigh - 6/10/08 at 05:27 PM

Since I was hoping to just attatch the driveshafts to the rear hubs in the same way as they were at the front, isn't getting a rwd axle going to scupper that one or can I just use the hubs?