machining Z/R32 calipers for thinner discs?

[oldcorollas]

is it possible?

they look like a fairly symmetrical design... meant for 30mm discs (or 26mm with the other Z32's)...
can you machine the inside of the two halves, machine in o-ring channel for the fluid, get shorter decent spec bolts etc etc... to suit a 22mm disc?

reason being that there's a certain 276x22 disc which is 5.4kg... vs 6.9kg for the nissan 280x30...(and similar for the other thiner neesan discs)

anyone done it? any good reason not to do it? the calipers look substantial enough in that area. and do not look like they would be significantly weakened.

it is for an unboosted car, weighing around 700-800kg, destined for sub IPRA trackwork (eventually)...

the other option is something like the RX7 calipers.. (lighter by 1kg) but they have smaller pistons, so makes it a little trickier to find small enough pots for the back..

[GTSBoy]

I have heard that once these calipers are split they never seal properly again. Don't quote me, but look into this before proceeding.

cheers

[oldcorollas]

thanks for that...
i expect the maching of the o-ring groove to be fairly critical for brake line pressures, as well as getting the damn things perfectly flat....

oh... you mean when split and just reassembled? hmm.. i wonder why (apart from o-ring damage/incorrect new seal)
i might split one anyway and have a look... not like they are expensive ;)

at worst, a new proper sealing method should do the job...

[260DET]

The one car that I know of didn't have any problem with leaking calipers but did have a continuing problem with warping rotors. 22mm thick rotors I think. Whether the warping was caliper related is another question of course.

[St00ge]

I would just get some ceramic backing plates made up for the pads to keep the pistons in the caliper with the smaller disc and stop heat transfer back to the calpier and fluid. Easier than messing around with the caliper and potentially causing a problem and helps with keeping the heat out of the fluid.