Another Wilwood question

[dcozzi]

I have b-body spindles, Kore3 hubs, C5 rotors (13" and 1.10" thick) and radial mount caliper brackets.

The Wilwood site lists 2 different applications.
http://www.wilwood.com/Products/001-Calipers/007-SL6R14/index.asp

The builder of the custom spindles says they are set up for Wilwood 120-8000-RS and 120-8001-RS. These show they are for 1.25" thick rotors.

The 120-8079-RS and 120-8080-RS are the ones listed for 1.10" thick rotors.

Their drawing
http://www.wilwood.com/Products/001-Calipers/007-SL6R14/dwg.gif
does not differentiate between the two. Just the different mount hole offset measurements for multiple thicknesses.

THE REAL QUESTION IS: Can you use a caliper that says it is for a 1.25" rotor on a 1.10" rotor without any problems as long as the caliper is centered on the rotor?

[dcozzi]

Nobody?

The question has boiled down to this:
Will the pistons travel too far out of their pots when the pads wear down and create an unsafe condition?

I calculate the pistons to travel an additional .075" out of their pots.

Anyone?

[Apogee]

It sounds like you're using C4 HD rotors based on the 13x1.1 dimensions in your post, not a C5 rotor.

As for your question, most calipers are fine with a small .075" difference, however every caliper is different. I would suggest contacting Wilwood for their take on it since they should know exactly where the piston rides relative to the seal. Personally, I'd probably just buy or make some 14/16 gauge pad shims out of stainless or Ti and run it.

Tobin
KORE3

[dcozzi]

Tobin, thanks for the reply. I am learning as I go and bought the whole setup already modified, sans calipers. I am trying to be precise so the digital caliper and calculator have become my best friends.

So I guess I have C4 HD rotors. I will try the shim idea. It will also let me use a 1.25" thick rotor later, if offset permits.

Wilwood would not give a definitive "yes" or "no" on the extra piston extension. I figure they were covering their bases in case of failure and I do not blame them.

Who makes pad shims?

By the way, nice hubs you guys make. First rate stuff!

[Apogee]

Thanks for the compliment on the hubs...we like 'em. I've seen shims sold everywhere from Ebay to the roundy-round suppliers (AFCO, Speedway, Coleman, etc), just keep in mind that they'll need to be specific to the pad backing plate that you're running.

The other thing to check is that as your pad wears, the backing plate needs to be fully supported by the abutment in the caliper. Worst case scenario is when all of the friction material is gone...but you really should replace your pads before it becomes metal to metal between the backing plate and the rotor. Generally speaking, once a pad hits 20-30% its original thickness, it's time for replacements since it no longer has the necessary volume to perform up to its design standards.

Tobin
KORE3