Maybe I'm missing something, but wouldn't a proportioning valve be a simpler way tune the bias?

its can only do so much if you upgrade the front too much.

Miatas, esp the early ones, use FWD sized rear brakes. You know how wrong wheel drive econoboxes are so nose-heavy? Well the back of such cars have next to no weight on them. Hence they use weak rear brake calipers when they use disc brakes all around. The inexpensive Miata inherited such calipers from the parts bin… SO…an adjustable prop valve can be set to full rear (no line pressure reduction) and still not eliminate excess front lock tendencies on many Miatas.

If race series rules and your wallet allow, it's best to set bias via hardware changes to get things close, with a tendency to rear lock first. And then fine tune with a prop valve. That way you can use pads with desirable behavior front and rear. And the bias is much more ideal during light AND heavy braking.

If you get bias decent during all out stops without using a prop valve, then it will be way too front biased the rest of the time. As in the fronts doing most of the work even when not braking very hard. This leads to excess wear and heat along with trail braking woes.

Ahh, thanks for the long explanation. Sadly none of this is very applicable to me ATM, but its still good to know.

Not sure how much it matters, but it looks like that info is for an RX7.

oops..my bad

Hate to bring back an old topic, but has anyone done a comparison between the sport calipers with sport rotors vs the m-tuned/stock 1.8 caliper with sport rotor?

Is it really htis cheap to get sport calipers with the mounting bracket this cheap?

https://www.napaonline.com/Catalog/C...+50042+2042021

https://www.napaonline.com/Catalog/C...+50042+2042021

Hell, that's cheaper than buying the mtuned brackets to retrofit my current 1.8 calipers.

Am I missing something???