Hey guys, I've got kind of a noob question for you guys. I've been looking into doing a full brake rebuild like new pads, rotors, lines, and rebuilt stock calipers. Since my stock master cylinder fluid reservoir is cracked I was thinking about upgrading that now as well at the same time.
My question is what is the difference between the 929 brake cylinder and the Wilwood 7/8 bore master cylinder?
Which one would you recommend and why?

I did try searching this beforehand but didn't have any luck. Your help is much appreciated.

 

the 929 master is 1" (or 8/8ths) so its bigger.

 

Is that the only difference? Any reason why one is preferred over the other?

 

Perhaps, you are asking the wrong question or your perception of how a master cylinder operates is flawed.

In any case, the stock master cylinder is 15/16th.
Most people change it to the larger 929 master cylinder when they get larger brakes to lower the pedal effort.

If you go with the smaller Wilwood master cylinder, it would result it higher pedal effort. Most importantly though, it more than likely does not mate up with the booster like factory or 929 one does.

Short version:

929 = bigger, bolts up
Wilwood = smaller, maybe does not bolt up?

Vince

 

This is 100% backwards.

 

And you would be correct

The right word would be pedal travel.

Larger bore = increased fluid displacement/pedal effort, decreased pedal travel
Smaller bore = decreased fluid displacement/pedal effort, increased pedal travel

Vince

 

I don't have a 929 master but from what I read, the transition from light breaking to ABS active/ full lock is more abrupt than the stock master. I also read the 929 may work better with wide rubber if the driver can get used to the touchier pedal.

 

I haven't done the swap yet, but the larger MC should provide more feel. Because the pedal requires more total force, you can modulate the lock more gradually with the same relative change at your leg.

 

anybody have any idea where i can get a 929 master cylinder for a reasonable price? any help is much appreciated!

 

Ray Crowe @ Malloy Mazda.
His contact info is in the sticky'ed threads in this forum...

 

Ray charges $126. U can also buy it at places for $80 with a returned core