ST205 Calipers with different discs??

[robd]

Hi, I'm looking at getting some ST205 calipers for my mk1 & just wanted to know(excuse my ignorance) what would happen if I didn't use the ST205 discs, say if I just went for some scooby discs or something like that? I know the ST205 disc is 315x32mm & you need to machine it down to 300mm, but if I got some scooby discs which are 294x28mm(I think) would they work? I am guessing it would mean the pistons had to push the pads an extra 2mm on each side of the disc, would this affect braking/pedal travel or work at all?

Main reason I was thinking about getting different discs as I don't want to machine down the ST discs plus ones like from a scooby are cheaper & you can get grooved ones off ebay for about £70, so would be cheaper & easier in the long run. I know I would still need to drill 4x100 holes as the scooby is 5 stud.

Any help would be great.
Cheers
Rob :)

[Jim-SR]

spacing is your biggest issue. the discs arent just a diameter, they will sit further away or closer to the caliper, so then you may need spacers too. ST205 discs are easy to machine, and the discs last a fairly long time. using discs from a different manufacturer entirely poses more problems than its worth, otherwise someone would have done it already

[robd]

Ah right ok, what about if I was able to get discs from another car that were say 298x32, would that work? Think the supra twin turbo ones are 32mm & just under 300mm! Is there an issue with going below 300mm on the disc size, like will there not be enough disc for the caliper to push against? I suppose really whatt I want to know is what is the main thing to look for, is it the 300/298mm etc is it more the 28/32mm etc?

Any idea how much it may cost to get the discs machined down to size?

Thanks :)

[biteme]

That's the JSpec Supra disc.

UK Spec (aka Export Spec) discs are 325mm

[Gary Symons]

As jim said the biggest issue will be finding a disk with the correct offset.
Where in the country are you? Adamh on here may be able to machine the disks, he is down south.

Also [shameless plug :shifty:] I have a full st205 setup for sale, see the link in my sig below.

[robd]

Ahhh right I see what you mean, sorry I wasn't thinking straight! So the offset of the disc will affect the wheel offset! Doh...I was just thinking about it from the size point of view! Doh! Makes so much more sense now! (hangs head in shame) lol :)

In which case then yeah I guess I'll stick with the ST205 discs.

I'm near Cardiff in South Wales. :)

Thanks for your help everyone. :thumbsup:

Oh also, do the ST205 calipers just bolt straight on or do I need to mod them at all other than getting the discs machined?

[robd]

Just wondered if anyone can help, I've tried searching the forums but can't seem to find what I'm looking for! Could anyone tell me all the mods I need to make to the ST205 discs & calipers to fit them to the mk1?

I know I need to get the discs machined down to 300mm & drill the 4x100 PCD but do I need to do anything else?

Any help would be great as I'm hoping they will turn up this week & want to get them on the car asap.

Cheers
Rob :)

P.S. Also if I fit the ST205 fronts but don't change the rears are the rears likely to lock up a lot?

[snowtigger]

No the fronts will lock up first before the rears with st205s,have you got the spigot rings for the front and the drill and tap and bolts to do the hubs.

[robd]

No I haven't got any spigot rings, what size do I need? Is there a thread that I can use as a checklist? What do I need to do on the drill & tapping front? :)

[Gary Symons]

No I haven't got any spigot rings, what size do I need? Is there a thread that I can use as a checklist? What do I need to do on the drill & tapping front? :)

Pauls original guide is in Twobrutal filestore here:
http://forums.twobrutal.com/downloads.php?do=cat&id=1