13BT_RX3

Anyone know what the bolt spacing is c-c on the 2nd gen RX7 brake master cylinder? Could someone measure for me? My RX3 booster can take a master with vertical mount like the 1st gen or horizontal like the 2nd gen. I measured my bolt spacing to be ~2.7". I hope that is the same as the 2nd gen. TII or 929 master would be nice since I have extra petal travel now that I have TII front calipers.

Thanks.

clokker

iTrader: (2)

The second gen bolt spacing is more like 3.25" so no, it won't fit.
If you're going to increase the size of the MC, you'll get the best results by using a matched booster as well. I'm not sure what the booster mount is like on your car but the second gens have a double firewall and require longer mounting studs to fit.

The 929 unit will work as will some Infinity and Subaru parts.
Some Honda boosters will also fit but you have to use the matching MC since they use a "clocked" mounting flange (bolt flange angled, not horizontal).

You may have to get creative with the brake lines as the port location and number may not match your stock cylinder.
This is not a big deal but something to be aware of.

If you're mixing/matching MC and booster- and there's no reason you can't- pay attention to the booster output shaft/MC piston clearance.
Most boosters have an adjustable shaft but not all, so watch out. Some of the combos I tried required machining a custom cap to make the non-adjustable shaft the correct length.
It's easier to get the booster/MC as a matched pair if you don't want to mess with this.

13BT_RX3

Very good info. Thanks.

I will have to spend some time in the wrecking yard and play.