What size rear rotor for Wilwood brakes?

[Guest Looking for apt in Alb Ny]

Hello I would like to have some input on the size of rotor that I should make hats for rear brakes 70-83 z and zx? Again I listen and feel it is the best way to make custom parts for us all.

Enjoy tha day Juan

[Jeff]

I would like to see them the same diameter as the front brakes but you can go with a thinner rotor. Everyone who is running these brakes should be running a proportioning valve so brake bias shouldn't be an issue. This is not an original idea I'm just stealing it from the Arizona Z Car setup.

 

[Sparky]

yeah, same size for sure, not really necessary, but nothing looks sweeter than HUGE brakes front and rear!

 

as soon as a front and rear package becomes available I will be buying your kit.

 

keep up the good work.

[Doug71zt]

I'm running .810 thick by 11.75 Wilwood rotors on the rear with 1.25 by 12.2 inch on the front - the brake bias is quite good without a proportioning valve ( I have one but it is full open) - the stock pressure reduction valve is gone also (its a 240). BTW I'm using 300zx tt calipers all the way around. I don't see any reason to go bigger on the early cars. 280zx may be a different story though.. Hope this helps - Doug

[JMortensen]

I'd like to see a braking system with aluminum hats and 4 piston calipers that would fit inside 15's. Road racing 15" rims and slicks are very common, 16's and 17's are not yet as common, so they are much more expensive.

 

I may be wrong here, but it seems like the only common brake upgrade with 15's is Toy calipers and 280ZX rears or Ross's rear setup. If I am wrong please let me know.

 

I don't like the Toy calipers because of their huge weight penalty (although I do have them on my car right now), and the rear doesn't seem to have enough braking power. At least my 280ZX setup doesn't and someone else was just complaining about another type too.

 

Jon Mortensen

[Guest Looking for apt in Alb Ny]

Its done Ill be looking into some brakes other than 300zx for 15 inch rims. Juan

[Doug71zt]

For 15 inch rims I think that the maximum rotor dia will be about 11.5". That is what Dave at AZ zcar used on his first kit. I think that he just turned down the 11.75" rotor. It was a tight fit on my 15" wheels. Building up a kit for 15" wheels should be easy as the wilwood superlight 2A caliper is a bolt-on and the mount for the rotor is a pretty simple piece. The only pain is turning down the rotors every time you need a set of rotors. Maybe Coleman racing or someone else could supply the correct size if you group ordered.

Cheers - Doug

[Guest JAMIE T]

The 12.2 rotor that is commonly availeable will fit under 15" wheels. These are the same parts Stock cars use under 15" wheels. I want to use 13" rotors up front and 12" rotors in the back so I can fit 15"x10" drag wheels and slicks.

[JMortensen]

I know this is kind of a new thread emerging here, but do you happen to know if the 12.2" rotors fit under aluminum wheels or only steel. I'm pretty sure Cup cars run steel, and it would seem that you've got a lot thinner material with the steel wheels. Not that steel bothers me, I just want to know so that I can buy the right stuff. Been looking at the Diamond Racing spun steel. They can be pretty light, but a little on the fragile side from what I've heard.

 

Jon Mortensen

[Doug71zt]

It's kind of a crapshoot when it comes to which size rotor fits under what wheel. I know for sure that a 15" wheel will not fit over my 11.75" rear rotor with a Z32 caliper. Single sided sliding calipers offer more clearance but not on my car thanks. You pretty much have to find someone that is running the same wheel or get the pieces and try yourself.

Cheers - Doug