FD- Master Cylinder brace, my take on it.

[wickedrx7]

After reading Kevin?s thread on his Master cylinder brace, I decided to make my own.  Being that I don?t have a welder and or ability to weld, I had to go a different route.  I had some large aluminum extrusion laying around that actually worked perfect.  I used the existing holes on the  strut tower and the other end just rest on the strut tower to give some additional bracing.  I like this route cause there is no drilling in the strut tower. 

I have some extra material and could make a few for people if interested.

Check out the pics and let me know what you think. 

[wickedrx7]

Some video:
No brace
]http://www.flickr.com/photos/wickedrx7/5059434529/#secret6188ec5727]

With brace:

[spacevomit]

Nice. The videos aren't working for me though. Never mind, now they are.

Edit: Am I missing something? I see the brace in both videos.

[wickedrx7]

Nice. The videos aren't working for me though. Never mind, now they are.

Edit: Am I missing something? I see the brace in both videos.

The brace is there, the bolt just isn't touching the master cylinder.  Using the bolt design allows me to add preload. 

[ProjectD]

how much?

[theantirotor]

preload the master cylinder?

[spacevomit]

I ASSume he means preload the structure as a whole, of the master cyllinder mounted within the unibody. Not the internal workings of it, but to take the flexibility out of the whole structure. Since it is basically held rigid in one axis, by the effect of being compressed.

Actually it looks like the structure is compressed both axially and radially. Sorry if I made any real engineers LOL.

[Shavel]

Nice work, simple and effective.  I'm going to need the yield strength on that extrusion before I buy anything from you .

[spacevomit]

I am guessing the yield strength is about eleven.

[wickedrx7]

I ASSume he means preload the structure as a whole, of the master cyllinder mounted within the unibody. Not the internal workings of it, but to take the flexibility out of the whole structure. Since it is basically held rigid in one axis, by the effect of being compressed.

Actually it looks like the structure is compressed both axially and radially. Sorry if I made any real engineers LOL.

YES! That what I meant.

[clocker]

Looks like you beveled the edge that rests against the tower...looks like it.
It's a nice piece.

Also, have you tried experimenting with different levels of preload?

[wickedrx7]

Looks like you beveled the edge that rests against the tower...looks like it.
It's a nice piece.

Also, have you tried experimenting with different levels of preload?

I did bevel the edge slightly.  I did try a few different levels of preload and it definitely makes a difference.  For the street I will probably run very minimal, maybe not even touching.  For the track, I will tighten it up to give more brake feedback and firmness.

[Kevin Doe]

My experience says you won't feel the difference between having it on the car vs not on the car.  Certainly not any difference between preloads.

After several autoXs that I've had mine on, I can't even tell the difference really.  Maybe on a road course where breaking zones are much longer and more "controlled" you could, but not at the autox, in my experience.

[jcm0791]

That is a very clean solution sir.  That is the highest praise I give ... well, until I copy your design ...then we will be into the "imitation is the sincerest form or flattery" range

I would like to relate a little tale:

When I bought my car (already LS1 converted) it was obviously also converted from auto to manual transmission.  The car suffered from a low brake pedal ... not soft, just low.  I found that when they installed the new pedal box they did not adjust the master cylinder pushrod length and a little extra free play there makes a big difference in pedal height.  The factory spec  for free play is quite a wide range here so I was a little surprised as to how much difference it made (more than an inch of pedal height at full service pressure for a fairly small adjustment)  Yes, yes ... I realize that we are dealing with a motion ratio and such .. I was still a little surprised.

Being that the master cylinder is on the same plane as the push rod, any reduction in movement should transfer into a better pedal (higher, firmer, and more consistent)

[Speedfab]

After several autoXs that I've had mine on, I can't even tell the difference really.  Maybe on a road course where breaking zones are much longer and more "controlled" you could, but not at the autox, in my experience.

Plus there are so many more potential breaking zones on a road course...  Hell, my junk is liable to break just driving through the pits.