SpecFC

Hey all,

Ive recently begun replacement of the brakes in my 87 TII.

In the effort to improve braking, ive spent some time trying to figure out a M/C upgrade.

Fortunately, I work in a parts store, so I have access to view any M/C I choose.

What I have found is:

The M/C from a 1993 626 V6 without ABS, and with a manual transmission appears to be identical to a S4 TII master cylinder, aside from having 3 outlets, and a 15/16'' bore as opposed to the 7/8'' bore of the stock TII cylinder.

I have yet to test fit it onto my car yet, but it appears as though there is hope for a direct bolt in upgrade for the M/C.

Ill let everyone know how it works out.

owen is fat

upgrade?
for what downfall?

SpecFC

An upgrade doesn't necessarily mean there was a downfall. However, there comes a time when stock TII brakes are not enough.

Turbo II

iTrader: (1)

Try tires yet? Never had a problem with my stock system.

RETed

Nice!
Keep us updated!
Converting over to a 929 set-up is a pain in the ***!

Might want to check out some of the larger / heavier Mazdas like the MPV vans and the Millenia...


-Ted

Turbo II

iTrader: (1)

OK, after maybe putting my foot in my mouth now I'm curious about this. I looked at the other similar threads listed below and also your on your site again Ted about brakes, and I'm going to go searching in a few for more on here also but... all I've ever seen are a lot of posts in the past saying "tires" (besides everything else about rotors/pads/lines/etc) being one of the more important factors but have never run across any before about upgrading the MC.

RETed

Sorry, I'm looking at it from a BBK perspective.
I'm interested cause of aftermarket brake calipers, which don't always come in "nice" piston sizes.
Being able to manipulate the brake master cylinder bore size is a plus.

I currently run Wilwood Dynalites with larger-than-stock brake piston sizes, so it's a little bit soft.
I can compensate a little with more aggressive brake pads, but you can only do so much.
Being able to change the brake master cylinder bore gives me more options...


-Ted

SpecFC

My real goal in all this isn't really about better braking, but better brake feel.

I highly doubt a bigger M/C will aid in braking other than providing more resistance to fade induced lack of brake pedal (more fluid movement=more compression of air bubbles). All I hope for is a stiffer pedal at light pedal pressures, its more of a stop and go gentle kind of driving thing im after than max preformance.

owen is fat

I know you are looking at a larger master BUT a smaller master would require more travel thus more feel... just like a longer lever arm provides more precision, but hey do whatever you want.

uptotibet

so did it fit?

SpecFC

Haven't had a chance to yet, been very busy with work, and holidays. Ill do it this week and post up my findings.

socalrotor

iTrader: (1)

so...........anything yet?

SpecFC

Yep, Finished last night. The master cylinder itself is identical to a non abs RX7 M/C.
Other than, the reservoir. The inlets for the 626 M/C are slightly too far apart for the RX7 M/C to mate right up. However, because the 626 has an remote mount reservoir, the new M/C also came with new fittings and tubes for the reservoir. SO, all that has to be done is to mount the rx7 reservoir somewhere convenient and above the M/C, then drill and tap two holes in the bottom where the nipples would be, and thread in the adapters. I will not be driving the car for a few months so I cannot report the benefits of the M/C, but I can say that it fits, with some minor modification.

Black91n/a

Some people like a lighter effort and more travel to modulate, others like a shorter stroke and more force to modulate.

One thing that vastly improves feel is a brake master cylinder brace. I just wrote up a how to on making one for an FC. Highly reccomended modification.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-diy-brake-master-cylinder-brace-718744/

SpecFC

I'm definately going to be doing that as well!