Rear Brake Conversion

[jamie_1992 66 1 Cars]

What has been done to upgrade gti rear disc brakes?

 

[ORB 227 1 Cars]

This has to have been covered more times than

 

"My car won't idle"

 

But it's not too hard. Swap brakes and compensators.

[Baz 421]

No need to swap compensators. Stub axles & everything beyond them & handbrake cables.

 

Not sure why though tbh.

[jamie_1992 66 1 Cars]

So what brakes do you swap them for?

[Baz 421]

I don't understand the question.

[jamie_1992 66 1 Cars]

Are there bigger brakes that fit on a 205 gti rear beam that already has disc brakes eg the 306 gti6 brakes if they are bigger I'm assuming they are

[ORB 227 1 Cars]

Drums are better in my opinion.

 

Most rear disc brakes on PSA cars are the same as GTI brakes

[Ryan 99]

The GTI-6 uses the same size discs as the 205.

 

There's no point to fitting bigger rear dsics, as the rear only does a fraction of the braking work.

Edited November 15, 2012 by Ryan

[welshpug 1,655]

306 used the same diameter, same caliper bar piston diameter, same pads.

 

to be blunt, it aint broke, don't fix it! in a light car such as the 205 you don't need any more braking force at the rear of the car, you'll simply lock up.

[Tom Fenton 1,540]

Read the original question.

 

To the OP. why do you think you need to improve the rear brakes? The rear 205 brakes do very little work as there is not much weight in the rear of the car. If you want some more rear brakes then re plumb to remove the standard compensators and fit a manual adjustable bias valve.

[jamie_1992 66 1 Cars]

Thanks for your answers

[Cameron 16]

GTi6 rears are a good upgrade if you've already done the fronts.

[Gman 29]

GTi6 rears are a good upgrade if you've already done the fronts.

 

Will a 2mm piston size increase really make any difference?

[welshpug 1,655]

12.5cm² over 12.16cm², 3% increase.

 

might be an epic maths fail mind

[Cameron 16]

You'd be surprised! As Tom said braking effort required at the rear is much less than the front so there's little point in fitting anything massive, but if you've fitted big brakes up front you will need to do something to balance things out again and the GTi6 calipers worked very well for me!

[Vili 18]

12.5cm² over 12.16cm², 3% increase.

 

might be an epic maths fail mind

 

Yep it's a fail. 7,06 cm2 vs. 8,04 cm2, that's 14 % increase. If I'm not wrong by using diameters of 30 mm for 1.9 gti calipers and 32 mm for 306 calipers.

Edited November 17, 2012 by Vili

[Cameron 16]

You are correct, sir! And that increase in area translates directly to a 14% increase in clamp force, which translates to a similar increase in brake torque. So yes, 2mm larger pistons will make a difference!

[welshpug 1,655]

how did I get it so wrong?

[Tom Fenton 1,540]

God knows, I have tried lots of different ways of incorrectly working it out in my head and still can't get anywhere near your answers. How did you work it out?

[Ryan 99]

diameter squared, times pi, divided by 4.

 

3.0cm x 3.0cm x 3.14 / 4 = 7.06cm²

3.2cm x 3.2cm x 3.14 / 4 = 8.04cm²