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Discussion Starter · #1 ·
In one of our Sunday night chats, I had a discussion with someone about caliper flex. I am sorry, but I am getting old and don't remember the handle of the person. I thought it was MM but I can't find it.

I got some information for you. I am headed out of town tomorrow (going to Bragg-Smith yahoo!!) morning so I won't be reading email so I'll put it here.

I hope you get it and I hope it helps some. Here it is:

Thanks for the e-mail... Yes, calipers so exhibit some flex, the extent of which depends on the design of the caliper. In general, single-sided piston sliding calipers tend to flex much more than dual-sided positive pressure calipers.

Based on what you have told me, your friend could improve his braking dramatically with simply a better compound on the Z06. We'd put him in our Panther Plus compound in the front and the rear. Also, you should do whatever possible to improve the cooling to the brake system; e.g. installing brake cooling ducts, removing dust shields from behind rotors, etc.

Please let me nkow if I can be of further assistance to you.

With Best Regards,

Andie Lin

andie w lin
vp marketing and product r&d
carbotech engineering
tel: 877.899.5024 | fax: 954.493.9669

568 Posts
He left out an important detail.. The difference between a floating caliper and a fixed caliper.

In any car, the wheel hubs and bearings flex in corners. As you load the outside wheels in a turn, force pushes the bottom of the wheel inward.

That bearing and spindle deflection cause the top of the wheel and rotor to move outward. That motion presses on the brake pads.

The change in the rotor plane pushes the brake pistons back into the bore. This is called 'pad or piston knockback'

So as you go through a series of corners and enter a straight.. You may find that you have a long pedal when you reach the braking point. Most drivers will 'double pump' the brakes to reset the pedal. This happens even in F1, CART, TRANS-AM - everything.

'Floating' calipers are used on production cars. The caliper is free to move side to side in response to deflection. There will still be some pad knock back, but it generally won't be as bad.

Fixed caliper designs tend to suffer from more caliper knock back.

That knock back isn't the end of the world, but it is an important point to consider when selecting calipers..

Race rotors are sometimes floated on the hats to which they mount. Floating the rotors is mainly to prevent warpage (from uneven cooling) and to keep brake heat out of the hat, hub and bearings. It might provide some small benefit in regard to knock-back, but I would not expect much.

My sources tell me the C5 calipers are Very good. If your friend is pressing so hard that he is concerned about flexing the calipers, I agree with Andie tht he probably needs better pads. I prefer Performance Friction 90's and 93's, but I have yet to try them on a C5.
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