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MG ZR ZS ZT Technical - Rear Disc conversion on ZR105

Does anyone know of anyone who can convert the drums on the back of my ZR105 to Discs and uprate front discs?

They are the only downside to a cracking little car

Cheers
Douglas

of course, you can still get some competition break pads from the SnR catalogue,just for the front discs though if the back drums cannot be converted.

http://xpowerforums.com/SnRCatalogue.htm

personally, I'm not sure I would prefer all round disks, it makes the breaking seem a bit hard, and on some cars the initial bite is too unsubtle for my taste.
Gary

Absolutely

this would have been the first significant upgrade I wold have made to my similar Labrat 214

the brakes just cant take it and fade badly
I often had nasty smells from them after a good hammering

Its a must just make sure that the upgrade fits under the rims,
whioch it should do the
Neil

Neil...any idea where i could get a rear disc conversion though?
Douglas

Douglas,

The rears only apply a small proportion of braking, however if changing to disc you may need a m/c change and deal with handbrake issue. As long as you uprate front by increasing disc size but reducing piston spec the f/R balance will stay same but fronts will have more heat capacity. If necessary you can have shoes made with upgraded material.

Paul
Paul

Douglas,

This subject has been covered at length - search the Rovertech archives and pose a similar question over on Rovertech.net BRAKES here:

http://www.rovertech.net

For what it's worth, unless you are uprating your engine and frequently do some heavy track use, for mainly road use a rear disc conversion is mainly a cosmetic exercise. The drums are adequate.

If you need better braking, a good upgrade on the front only should be sufficient for road use. I believe a popular upgrade for R25s and lower spec ZRs are the fronts from ZS 180 and the top spec ZR160.

Neil 'Gothenburg Labs' WROTE:

>>I often had nasty smells from them after a good hammering<<

In my experience, this is the case with most standard road cars subjected to some serious and repeated braking. Perfectly normal.

Those 'smells' would be mostly from the front brakes alone as on any car, particularly front wheel drive ones, it's the fronts that do most of the work.
John McFeely

Douglas, not read the link that John mentions, but IIRC to replace the rear drums for discs would require the replacement of your ZR105 rear axles with those from a ZR160 - the work is quite involved and expensive, but that is what you are prepared to do, then no problem.

The front disc conversion, conversely, is simple: replace the discs and calipers - and job done.

One thing I'd suggest you consider- other than for aesthetics, why do you want rear disc brakes? The weight distribution on the ZR is heavy front biased. The weight bias over the front wheels increases significantly as a function of deceleration and the height of the centre of gravity: a 1G stop will see probably somewhere in the region of 80% of the vehicle's weight over the front wheels - and the front brakes therefore performing 80% of the work...

When people say that the rear brakes "are just along for the ride" in a FWD car, they're not far off the mark.

Personally, I'd perform the front brake conversion, and then take stock as to whether improving the rear brakes is strictly necessary above and beyond upgrading the friction material used.
Rob Bell

thanks for all the advice folks, i think i will just try the uprated discs and pads and calipers on the front,

off to the scrappy to find a crashed ZS180 ot ZR160!!!
Douglas

try Rover Breakers on 01606 738873, I've just ordered a wing mirror from them.
Gary

cheers Gary, where in the country are they?
Douglas

Go bigger discs and pads at the front first
the solids just arent up for sustained hammering

but yeah it actually IS probably all the effort of doing the rears!



Neil

http://www.roverbreakers.com/

the phone call always sounds like the North East of England somewhere, but my bits always come in the post.

I'm on my second wing mirror now, the first time it was bashed off for me. The second time I was driving through a familiar country lane. When the bushes tickle the wing mirror I know I'm close, except that is, when the bushes are hiding a fallen post or branch.

At over £120 brand new, I wish there was such a thing as wing mirror insurance.
Gary

This thread was discussed between 23/09/2004 and 24/09/2004

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