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.

 

upgrade?
for what downfall?

 

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

 

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

 

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

 

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.

 

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

 

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.

 

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.

 

so did it fit?

 

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

 

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

 

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.

 

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/

 

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