thanks disappointing... you have it turned all the way in and your still not getting enough rear bias?

I was checking parts the other night and my 90 calipers are much different than the 97's on the car. the piston is smaller and the "fingers" are shorter. I'll snap a pic tonight to compare the two.

 

no, that's its "lowest" setting. With it set at it's lowest setting you can reduce the rear pressure 57%. I'm not reducing it that much....I have plenty more room to increase the rears if need be. I'll probably have to crank it up when I put my xp10/xp8s on.

 

NA6 and NA8 calipers are indeed different. NA8 brackets on NA6 calipers work, but are not the most ideal set up. Uneven pad wear is a symptom of single piston calipers.


Front brakes are always 100%. Rear brakes are always less*

*under light braking, the prop valve does not reduce pressure to the rears.

 

Don't worry folks.. Our rear 10.9" kit will help solve a lot of your bias issues.

 

So in Wilwood's site it says its maximum setting (all the way screwed out I believe) is 57%. That means that when all the way screwed out, my rear brakes are at 57% of my front's, which is 3% less than my stock '93 proportioning valve, is this all correct? I have mine cranked all the way down (which means they're getting the same pressure as the fronts, right?) and I still can't get the rears to lock up first, its very frustrating.

Ben, you say uneven pad wear is a symptom of single piston calipers, do you think putting 1.8 calipers on would help, or would it not be worth it until upgrading to multi-piston calipers?

 

First, what pads are you running? If you have a less aggressive compound in the rear, you'll lock fronts first all day long.

1.8 calipers are single piston too. I am looking into a Wilwood or AP Racing upgrade right now.

 

A bracket that allows us to run generic Willwood calipers and big rotors would be nice.
Wilwood Brakes, Hubs & Brake Lines

Chris

 

Sav,

Here's the three Wilwood options that looked best to me for a complete front system. You've seen it, it's at the end of your "do I need big brakes" thread.

https://www.miataturbo.net/forum/t33100-3/#post390723

Best prices I found for Wilwood are at Autofab race cars. They don't/can't publish them. Gotta email or call with the part #'s you want.

Found a company several weeks ago that makes maybe 50 models of aluminum caliper brackets. Of course I didn't bookmark them.... Gotta find them again. They are a likely prospect for getting something made for us cheap diy guys.

 

cool, I'm still tinkering with mine. I just misread your post, too much work and not enough . you might want to run the same compound front and rear.

I have mine 3 full turns in and I'm still able to lock the front pretty easy. I'm running the same compound front and rear BTW.

are most people running theirs cranked all the way closed? I realize that everyone will be running different set-ups, just curious if most are using all the bias the prop valve has to offer.

 

I took mine out of the package and cranked it in 20+ turns before even installing it. It's not totally bottomed out, but it's damn close.

 

I'm running porterfield rs4 race pads on all four corners, so it's really bugging me that I can't lock up the rears. Locking the fronts is not a challenge what so ever. For $60 or so for used 1.8 calipers, It would be worth it for the longer prongs to help keep down on the taper pad wear.

 

The Miatas when running a decent suspension, 15x9's with race tires and a wing can use a surprising mount of rear brack. Top stock class autocrossers have been known to run a softer pad in rear. The OGK has a Wilwood BBK with 11" rotors front and rear running XP12's F & R also. With that combo, I'm finally able to run the prop valve somewhere other than wide open (max rear).

For most guys with Spec Miata-ish set ups, one compound softer in front like 10/8. For the really fast winged cars I'm recommending 12/12.