Well I’ve been promising this for a long time now, and it’s finally happened, I’ve taken the pictures and here’s my brake master cylinder brace how to.

Thanks to the engine bay layout of our cars, it’s extremely easy to build and install a brake master cylinder brace. It makes a very noticeable difference to the brake feel as it helps reduce the flexing done by the firewall and the brake booster. Have a friend push hard on the pedal while you watch the master cylinder and you’ll clearly see it move. I got a compliment on the stiffness of my pedal from an autocross tech when I was still using single piston brakes and stock lines. My brakes now feel better than those on my uncle's Porsche Cayman S (standard, not ceramic brakes). Yep, it’s that good.

You can use other materials, other shapes of stock, make it fancier or whatever, I’ll just go through what I did as it’s know to work very well, you do it how you want to.

Start with a piece of 2” x 2” x 0.125” square steel tubing about 5” long, two 3/8” x 1” bolts, a 3/8” x ~4” bolt and four nuts. Start by removing the stock ignition wire bracket from the strut tower, this is where the brace will be mounted. Now you can line up the piece of stock vertically and mark it for the location of the main bolt that will serve as a stopper pressed up against the master cylinder. Remove and drill the piece. You will then need to drill two holes through both sides of the tube on the adjacent sides, this is where it’ll bolt to the strut tower. You will then need to line it up and drill the mounting holes, a 90 degree drilling adapter was required for me due to the intake manifold/solenoid rack interference. Paint the bracket and the new holes in the fender. Once the paint has dried you can install the stopper bolt loosely and then bolt the brace to the strut tower. You will then need to tighten the nut, pressing the bolt against the master cylinder, giving it a bit of preload and tighten a nut on the back side to make sure it stays it in place. Then you can use a zip tie to secure the wires to the extra hole on the brace since there’s no more stock bracket. That’s all there is to it, now you’ll be rewarded with a wonderfully stiff pedal.

Please ignore the wiring, I know it’s a messy, it’ll get cleaned up at a later date.

 

Nice, thanks! I will have to try this.

 

Nice! Thanks! Would there be any advantage doing this to the clutch master also? Just wondering...

 

sweeet

 

Probably not, for two reasons.

First, the clutch MC is located closer to the firewall/fender joint so there is less flex to begin with.
Second, when you press the clutch MC the slave/arm move to the limits of the hydraulic action unlike the brake which hits resistance with lots of pedal travel left.

Basically, there is nothing on the end of the clutch hydraulics that is fighting back so the firewall isn't flexing.

* I just realized how difficult this is to explain simply and lucidly (or maybe it's just too damn early)...

 

I wouldn't do the clutch, there's no point really, I mean when was the last time you were threshold clutching?

There is some resistance, but it'll be a lot less than the brakes.

 

Someone archive this! I may have to try this on my car!

 

looks good! but that wiring makes me cringe a bit...

 

The wiring's not bad, never had a problem with it, it's secured and routed away from moving parts and anything sharp that could cause a short. It's just a little messy and there's more extra wiring than most people have (3 extra gauges, CDI, battery relocation, rpm switch for aux ports since the computer stopped sending the signal).

Anyway, this isn't about the wiring, it's about the brace.

 

Looks like a good idea! I'm going to have to check out and see how much the master cylinder moves tonight, then add another project to the list.

 

Just did this mod tonight. Took the FC around for a while and I notice the difference! Very stiff pedal feel now. I ended up painting the bracket and using a nice shiny silver bolt!

GOOD, CHEAP modification. Thanks black91n/a

 

Thats just sexy..

 

Just PM a moderator for the section too get something archived.

I have now archived this. Good info Black91n/a!

 

Oh awesome!! I really want to do this. I wasn't too happy with the SS lines that I put on. I still get mushy brake feel. I'll have to do this so that it gets better. Awesome!

 

It should feel fantastic with the SS lines. I am still running factory lines and the pedal feel is still improved tremendously.

 

I checked the firewall flex on my car and noticed when pushing all the way down it moves at least a 1/4 inch that is alot of give in the firewall, and exactly why this is a great idea.

 

Thanks for the kind words. If you're looking for more cheap/simple mods to DIY that make a noticable difference, here's another one I did a while back: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-build-lower-arm-bar-under-%2415-448638/