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It is to keep the master cylinder from moving
under braking extreme conditions..

Force takes the path of least resistance..

Lots of force on the brake pedal
can cause the firewall to flex resulting in wasted motion..

Or something like that... :wink:
 

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SO that guy can feel like 1/32 of an inch of flex when he depresses the brake pedal? wow.
 

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Master cylinder brace, and your firewall, under racing conditions, flexes a hell of a lot more than you'd think. Just take a look the next time you manually bleed your brakes. I built one of these for my EG when I tracked it, the brakes in that car were incredible and this mod just added to the solid feel. For a street car, no, for a track car, yes. And I will be building ONE for my car before next season to complement my full Type R setup.

D.
 

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I think before anyone gets excited about that little scrap piece of aluminum extrusion you should open the hood, and watch the firewall as a friend pushes down on the brake pedal progressively harder. The maximum force the firewall will ever see is the exact same force as your foot is applying to the pedal. you may think that the force must be much greater because of the torque multiplication because the MC clevice is mounted closer to the brake arm pivot. However the pivot is also mounted to the firewall and thus cancels that extra force. Plus because of the brake booster you don't even have to push as hard as without one. I'm willign to bet that foot pressure alone on the double steel walled firewall doesn't result in much flexing at all.
 

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Masta, I will check it out this weekend when i get home to my car. I'm still skeptical, but I'm not saying that you are wrong.
 

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CRXBart said:
I have a 1" mc and it flexxes my firewall substantually. I am gonna fab one up for my car.
A 1" MC? and what calipers are you running? If they're stock bore then of course the firewall felxes more. You're having to apply substantially more effort with your foot just to get the same braking force. A bigger bore MC doesn't give you more braking power.
 

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jmart said:
CRXBart said:
I have a 1" mc and it flexxes my firewall substantually. I am gonna fab one up for my car.
A 1" MC? and what calipers are you running? If they're stock bore then of course the firewall felxes more. You're having to apply substantially more effort with your foot just to get the same braking force. A bigger bore MC doesn't give you more braking power.
I have Accord Wagon Calipers in the front, and 90-93 Teg in the back. BTW who ever said stock brakes are good is crazy. I've warped a ton of stock rotors in the past. It used to be a monthy procudure. Once I switched to the 11.1" setup no problems in 3 years.
 

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CRXBart said:
jmart said:
CRXBart said:
I have a 1" mc and it flexxes my firewall substantually. I am gonna fab one up for my car.
A 1" MC? and what calipers are you running? If they're stock bore then of course the firewall felxes more. You're having to apply substantially more effort with your foot just to get the same braking force. A bigger bore MC doesn't give you more braking power.
I have Accord Wagon Calipers in the front, and 90-93 Teg in the back. BTW who ever said stock brakes are good is crazy. I've warped a ton of stock rotors in the past. It used to be a monthy procudure. Once I switched to the 11.1" setup no problems in 3 years.
Okay, well the teg calipers in the back are the same size as the crx Si calipers. And while I haven't measured the accord wagon calipers (although I've researched them, and every other big brake option, extensively), I suspect they aren't much bigger bore than the crx ones; just using a bigger rotor for mechanical advantage. That being said a bigger MC is still not justified. In fact, its decreasing your possible braking force. You make up for it somewhat with the larger front rotors, but in the end you've lost braking sensitivity as well. Now I don't know if you race the car at all or just street drive. Each has its diff demands. On the street you prob don't need that kind of sensitivity, or won't bother to notice it. However, I can't imagine warping all my rotors in a single month. I drive hard and often and for long distances sometimes throught southern california at 100 degress outside. And driving like a madman I've not managed to warp the rotors. I'm not saying that the stock Si brakes are the best ever put together, but they are pretty damn good, and disagree, i don't think they are crap. not so far as to say I wouldn't get bigger brakes if I did an engine swap or started driving a lot faster thus necessitating the need to stop much faster. As for now, my fully rebuilt stock Si braking system can operate at the limit of my summer tires, so I'm not too worried.
 

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jmart said:
Okay, well the teg calipers in the back are the same size as the crx Si calipers. And while I haven't measured the accord wagon calipers (although I've researched them, and every other big brake option, extensively), I suspect they aren't much bigger bore than the crx ones; just using a bigger rotor for mechanical advantage. That being said a bigger MC is still not justified. In fact, its decreasing your possible braking force. You make up for it somewhat with the larger front rotors, but in the end you've lost braking sensitivity as well. Now I don't know if you race the car at all or just street drive. Each has its diff demands. On the street you prob don't need that kind of sensitivity, or won't bother to notice it. However, I can't imagine warping all my rotors in a single month. I drive hard and often and for long distances sometimes throught southern california at 100 degress outside. And driving like a madman I've not managed to warp the rotors. I'm not saying that the stock Si brakes are the best ever put together, but they are pretty damn good, and disagree, i don't think they are crap. not so far as to say I wouldn't get bigger brakes if I did an engine swap or started driving a lot faster thus necessitating the need to stop much faster. As for now, my fully rebuilt stock Si braking system can operate at the limit of my summer tires, so I'm not too worried.
Yes the Teg rears are the same size as the CRX Si rears. The Accord Wagon on the otherhand are substantially bigger than stock, and do require more fluid. The pistons are huge I wish I had a pic to share. With the 13/16's MC it was actually kinda unsafe to drive the car. The pedal went real close to the floor, even after a full bleed job, now it is very sensitive, but not overly. The setup I'm running is actually the same setup allot of Honda Challenge H-1 racers run. I know for a fact that Kevin Helms Nat. #3 runs the exact same setup, and he does actually run a MC brace similar to the unit pictured. I wish I could run smaller, lighter, brakes so I could run smaller, lighter, wheels, and cheaper slicks, but the brakes are more important to me. I couldn't keep stockers long at all before warping, aparently I drive my car harder than most for at that time it was street driving exclusively.
 

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I'm with Bart, the stock brakes are pathetic. Even in my stock motor car, I completely overwhelmed the brakes. I had painted my front calipers gold, and at the end of the first track day, the calipers were blue/purple from the extreme heat AND the dust seals were crispy. On the track I was getting complete failure due to fade which forced me to lightly tag a tire wall. Not fun when you're doing 80mph and the brake pedal goes to the floor. The pistons in the TYpe R calipers are huge(same as Accord wagon) and the 15/16th's M/C is required at minimum to push enough fluid. Like I've said before, I much prefer a harder, shorter travel brake pedal and with the larger M/C my brakes "FEEL" 100% better. The M/C brace and steel lines just add to that feel and confidence that I won't be losing my brakes at 100mph going into a tight left/right "busstop".

If I didn't track my car would I bother with big brakes and a M/C brakes. Not a chance, there is no need UNLESS you have a B or K powered car.
 
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