Hi All,

I was just doing a search on the 929 master cylinder upgrade and I didn't see anything come back for the Gen I crowd. So I decided to crosspost this link from the Gen III forum.

929 mster cylinder

I just asked a question in the thread, so hopefully someone will respond in a non-snotty fashion and we'll have the info here whenever it's needed. And if anyone here has any insight, experiences or questions, hopefully they will get addressed as well. This is something that I think I have decided to do with my Rx-7 while it's being rebuilt.

One

 

From what I understand,the 929 MC will bolt to an FD or S5 vacuum booster.It will not bolt to a S4 booster,so Im doubting it will bolt to an FB booster.

Anything is possible if you can do machine work.Any type of adaptor can be made,and pushrods can be modified to make any setup functional.

The question is,is it worth it?
The 929 MC is a full 1/16" larger than the TII MC,which in turn is bigger than the FB master.If your running stock single piston FB calipers,then theres really no point in going as big as the 929 MC.Youll just have a rockhard pedal and not enough booster effect to counter the larger MC.
The S4 TII master would be a big improvement and is more likely to fit up.I know for a fact that the S4 master and booster will bolt up to an FB firewall,I run them both with my 12" front brakes w/TII calipers.The clutch master has to be clearanced a little and you have to run 2 of the aluminum spacers,but it does bolt up.

If you REALLY wanted the 929 MC,then Id recommend finding a S5 TII booster to get it mounted up.The S5 booster should be the same size as the S4,just with a different MC bolt pattern that is compatible with the 929 MC.
Not 100% sure,just guesstimating......

 

well, okay ... i'll try the S4 setup. i don't have ready access to a shop or the right tools for machine work and if it will bolt up (pretty much) as you said, then it should be good enough to give me what i want ...

thanks

 

I run the 929 Master, bolted onto a S4 N/A booster.

I would recommend what Steve posted.

 

thanks, Alex

 

Should be a big difference.
The TII has 4 piston calipers up front and singles piston rears that are roughly the same size as FB units.The extra fluid needed to actuate a pair of front 4 pots should make for a very stiff pedal when ran with two single piston front calipers.

Youll need a grinder to clearance the side of the clutch MC,thats about it.Just be sure to stack your 2 spacers and check the pushrod clearance.Im pretty sure I didnt have to do any adjustments,it just went together....

 

[QUOTE=steve84GS TII]is that spacer something that i can order with a part number or is it something that i'm going to have to have someone fabricate for me? i'm pretty sure i'll be able to handle the grinding on the clutch master by myself with the tools i have.

i really appreciate your help, Steve.

 

i think that spacer is there stock, i know ive seen it, but it isnt in the parts fische anywhere

 

Its there,usually theres just one.
Im pretty sure they are the same between the FB and S4 TII, since the firewall bolt patterns are the same.