FE-FC Holden Discussion Forum

I have just collected a pair of HQ stubs which i plan on fitting VN/VP rotors to but which calipers will mount to the stubs and suit the rotors ? or other common rotors than i can use HQ-WB calipers with and have commo stud pattern ?

thanks,
Nick.

Nick try buying HQ-HZ rotors blank from your brake supplier and drill them to suit Commodore stud pattern might be an option .......FC427.......

 Yes it could well be at least then i can use common calipers.

I've used the commodore rotors and HQ calipers, but I think the calipers had a washer fitted between them and the mount just to centralize them. Works fine.
(The rear end has commodore caliper/brakes)

sgo From memory I think with this set up there is the problem that the HQ / HZ rotor is thicker than the Commodore rotor and as the pads get towards the end of their life the piston is pushed to far out of the caliper to be supported safely also the addition of spacing washers would make this worse ........FC427......

 The commo rotors are thinner so the washer must work like a spacer ?

The washer was between the caliper and stub-axel, on the mounting bolt, so only moves the caliper inboard a touch. It centralised the caliper over the disc.
I might have to keep an eye on pad wear to keep the pistons in ???
Whats the difference in commodore to HQ disc thickness?

 Roughly 4mm i believe, so when your pads wear down watch out.

3.4 mm actually. The minimum thickness for a HQ rotor is 24.5mm and a Commo rotor STARTS at 23mm. This would have to be one of the unsafest things to do as far as brakes are concerned. Its OK for you as the builder because you know the risk and most likely wont let the pads wear down do the minimum, but later on down the track another owner may not realise the risks.

Ken

I said roughly, anyway i emailed hoppers about redrilling HQ blank rotors but at $180 each ( when normal HQ rotors are no more $120/pair) i'm looking for other alternatives. What about splitting a caliper and milling 2mm off each side or machining a spacer to press into the piston cups so that HQ-WB calipers can be used ?
 Or a simpler idea of just using 1 fully ground down pad plate as a spacer ?

Hoppers were always expensive ring around .......FC427.......

Now that you've got me worried about my set-up :o
A stepped spacer that fits into the end of the piston  and extends its height by 2mm sounds like it would work?
If you go that way, do 4 for me?
cheers, George.