Ap racing calipers and disc offset

[speedysaab]

My brakes are now shot on the front of my 99 track car so I think its time to develop the ap racing calipers that are dying to be taken off the shelf. I'd like to keep the 15 inch wheels as I think these suit the car well. I don't have the bells to mount the 310mm disc made yet. Is it ok to inset the disc by a good 15mm as this will still clear the tie rod and ball joint and free up loads more space in the alloy for the caliper and then only require a 10mm spacer for the wheel ( this can be incorporated into the bell)

Is it ok for the bell to have quite a bit if depth to it?thanks
Rob

[Mezzanine]

It's ok for the hat/bell to have the depth you describe, but keep a close eye on the lower ball joint- the stock vented 86/87 rotors don't clear it by much, so I don't think you want to add more depth to the hat. What mount do the AP calipers have? 3.5" lug or radial? If they're on a 3.5" lug, I'd be very surprised if they clear a 310mm rotor. What is the mount height of the calipers? That is, the distance between the mounting lugs and the top edge of the brake pad? This stuff isn't hard to work out, but it does take a little work. What is the bolt spacing for the rotors you've got? 8x7?

If you have radial mount calipers, then you can easily place the caliper where you need it to adjust the rotor offset. The stock hats are already very deep so you should be able to move the caliper outboard a bit and use a shallower hat.

Fitting any of the above inside a 15" wheen is going to be very, very close. With Radial mount Wilwood Superlites, you'll have a 7" outside radius to clear a 12.2" (310mm) rotor.

[speedysaab]

So a track day was booked at croft as a birthday present and the race was on to get the 99 ready for its outing.

Polished up


Brakes "upgraded" with home built AP Racing setup

Billet bell production










Croft circuit

[speedysaab]

The rears - especially the right are still locking on heavy loading - I've done away with the servo and diagonal spit and made up a balance bar setup:















Hopefully will manage to fit to the car soon.........

[Krizzie]

That looks so awesome!

I'm looking into an upgrade as well, but I would like to keep my 16" deep dishes. which are almost as cramped inside as a 15" wheel.. preferably without spacers since they already poke out further than stock 900 rims.

[speedysaab]

Thank you - all looking pretty cool and actually quite subtle

I did end up putting a 10mm spacer on as it was very very close without and i was worried about gravel etc

Actually a bigger disc may have actually helped as I could then of offset it further in the car without hitting the caliper pickups on the inner diameter of the disc