Master Cylinder Upgrade

nfs13b · Postby **nfs13b** » Thu Oct 05, 2006 1:12 pm

Hello all,

The time has come to look at upgrading the Master cylinder in the mx5.

I have searched and on the miata site they say you can use a 929 1\" bore MC + booster fairly easy.

Just wondering what others who upgraded their brakes have used or if everyone is still using the stock setup.

thanks

nfs13b · Postby **nfs13b** » Fri Oct 06, 2006 5:00 pm

anyone?

irwin83r · Postby **irwin83r** » Fri Oct 06, 2006 7:36 pm

what brake system have you upgraded too?

i'm running standard cyclinder, from NB8A on NB8B+ calipers.. but i dont know if theres a diff between the master cylinders on them anyway..??

if your using a brake system of another car could you also use that cars brake cyclinder?

if their willow's or ap's PM CT, brian, or boyracer they have all done non factory brake upgrades and would be in the know.

CT · Postby CT » Sun Oct 08, 2006 10:06 pm

There's a few different MC's that are stock on the MX5. There are 7/8 and 15/16 bores both in 3 and 2 port. I run an NB 15/16 2 port on my NA race car without a booster and it's excellent. I think the 929 one is only 15/16th anyway so it is highly likely it's the same MC. Brake upgrades are totally dependent on what you are trying to achieve. For 95% of applications, the good-win racing version 4 BBK is the go. Works very well with the booster. I am waiting on some 295x26mm hatted rotors at the moment for my SE which will run either 4 or 6 spot calipers - depends what fits. Stock MC should be fine with it - I hope.

nfs13b · Postby **nfs13b** » Mon Oct 09, 2006 12:13 pm

At the moment I have some large Wilwood front calipers and the stock rears. I want to change the rears to something fairly larger but still keep the handbrake.... I have been told some falcons have this.
(And I have an adjustable proportioning valve)

My brakes feel spongey at the moment and I want to upgrade to something that is a little firmer and not put my foot to the floor.

My biggest problem is that I need bigger rear brakes so I can hold the car at 5000rpm (with the auto) on the start line and not have it creep forward.

Any ideas how much the 15/16 mx5 master cylinders go for?

CT · Postby CT » Mon Oct 09, 2006 12:23 pm

What are the specs of the wilwoods, ie piston sizes, model number etc etc. Is your current MC a 7/8th? MC's are pretty cheap aftermarket or from wreckers, less than $200 but you might alsobe able to look at other options as well.

nfs13b · Postby **nfs13b** » Mon Oct 09, 2006 12:29 pm

CT wrote:What are the specs of the wilwoods, ie piston sizes, model number etc etc. Is your current MC a 7/8th? MC's are pretty cheap aftermarket or from wreckers, less than $200 but you might alsobe able to look at other options as well.

The wilwoods are pretty big, I dont know what model etc they are, but they are 4 piston calipers, on a large rotor and I cant fit anything smaller than a 17 inch wheel on the front.

Yes, the MC is a 7/8" Would I be able to keep my current booster if I went the NB MC upgrade?

CT · Postby CT » Mon Oct 09, 2006 2:50 pm

OK, so unless you know the piston sizes on the caliper, most of this is just guesswork. Measure the diameters of the pistons and check through the wilwood website to determine which model you have got. You will need a matching booster with the MC as they changed MC piston design for the 15/16th ones.