993 Big Brake Kit: Brake Master?

[MyBoyBlue]

I purchased a used 993 Big Brake Kit a long time ago and haven't gotten to installing it yet.
I was wondering if I needed a special brake master cylinder to go with it?

[DeaconBlue]

Which RX7 do you plan to install these on?  If I read your signature correctly, you have an FD, correct?

Do you have both the front and rear calipers, or only the fronts?

Which 993 model donated the calipers?  Per the PET site this is the piston size info on the calipers in question;

993RS and TT use the same front calipers with 36mm/44mm pistons
993RS rear uses calipers with 30mm/36mm pistons
993TT and 4S rear uses calipers with 28mm/28mm pistons
all other n/a 993 use the small body calipers with 30mm/34mm pistons

From there some math calculations can be done to answer your question on master cylinder sizing needed for this potential upgrade.

[MyBoyBlue]

'93 FD R1
Only the front setup.
Don't know what 993 it came out of, bought this slightly used; they were on an FD.

[mefarri]

Brake*

[MyBoyBlue]

Brake*

:facepalm:
Fixed, thanks

[DeaconBlue]

The front calipers for the '93-98 FD have 36mm/36mm sized pistons.  The '99-02 RS/RZ front calipers had 34mm/38mm size pistons.  The piston area is not that much different with the RS/RZ calipers.  But with the 36mm/44mm Porsche Big Red calipers, that is going to require a lot more fluid flow and the brake balance will be heavily front biased without a corresponding rear upgrade.  Neither is very advantageous.  Unless you are planing to use this car mostly at the track, I am not sure that the added fade resistance this option would potentially offer is worth all of the other modifications that will be required to make this a balanced setup.

I would think a better option would be the '99-02 RS/RZ front and rear upgrade.

[mr3plus1]

929 Master cylinder will accept your FD reservoir and bolt up to the booster no problems.  Its a bigger internal bore and what most of the guys go to when running big brake kits to keep pedal travel the same.  Look up the install, because you'll need to custom make one of the lines.

[onefastrx7turbo]

I have a 929 master cylinder and booster from my FC if interested. Im going tandem master cylinders

[MyBoyBlue]

I think I'm going to end up selling my BBK or just wait until farther down the road. It's not in my budget right now to buy a rear BBK. My just go with the RS/RZ setup depending on what they go for (front and rear).

Send me a PM with what you want for the 929 and does it come with the custom made line?

[Brent]

You probably have the Big Reds from the 993 TT.  MovIt use to make a kit a loooooooong time ago(circa mid 90s).  I ran them for a few years on my previous track car without issue with the stock Master Cylinder.  They are incredible brakes, but are a little on the heavy size.  Still, being able to drive a fast car hard for 45 minutes on track without the first issue is worth it's weight in gold.  If you have the cross drilled rotors(stock 993 rotors), I'd send them off to Coleman to have blanks or slotted made.  Crorssdrilled rotors will crack significantly faster than non crossdrilled.

[wickedrx7]

I have a slightly used reman 929 master cylinder that I can sell for $100 shipped. 

Thanks
Jon