Complete adjustable brake proportioning kit

One of the best ways to get the most out of your brakes is to adjust the brake proportioning, or bias. The ideal brake bias depends on your ride height, the amount of traction you have (both due to your tires and the surface you're driving on) and the specification of your braking system. You always want the front brakes to lock up first for stability reasons, but Mazda was extremely conservative and so the rears never have a chance to make much of a contribution.

The proportioning valve drops the rear brake line pressure to a lower amount than the front. This adjustable proportioning valve replaces the fixed factory unit and allows you to adjust your brake bias for the perfect setup. We always have a way to adjust our brake bias in our competition cars. The valve allows to set the rear pressure anywhere from 43% to 100% of the front pressure, and it will approximate the proper curve required like the factory one does.

What makes our kit different? Our exclusive 1/8 NPT to M10 inverted flare adapter. This looks like the common SAE version (a pair of those are included with the proportioning valve from Wilwood), but will allow you to install this valve without having to reflare your brake lines. These adapters are impossible to find, so we have them custom made.

The kit includes everything you need to make installation very easy. No flaring or line bending required! The fittings are made of brass to ensure a better seal both on the flare and the tapered pipe threads when compared to harder materials. Compatible with all 1990-05 except those with both factory-installed Sport brakes and ABS. If your car has ABS but not the Sport brakes, this proportioning valve kit will still work for you. This kit is for NA and NB Miatas. The NC and ND cars with ABS use electronic proportioning, and the non-ABS NC would need two of these to work properly so we don't recommend it.

Will fit any car that uses metric brake lines and inverted flares, such as Honda or Toyota. Most Japanese imports should be able to use this proportioning kit. Note that we cannot confirm fitment in non-Miata applications, and we have had reports that some other brands have an unthreaded "nose" on the end of the flare nut that will prevent proper engagement with the threads on this part.

Includes:

Wilwood proportioning valve M10 inverted flare to NPT adapters - FM exclusive parts! M10 inverted flare union

Warning - having too much rear bias can make your car very unstable. Please spend some time testing in a controlled environment.