Paul,
Going by my book, paint code E is metallic frosted pine. My paint code is W.

Looks very similar though.

Yes it was, but the R31 cals seem just as effective and maybe easier to find. They look beter too
I guess it comes down to what I can find @ the right price

Mark,

If you want more clamping pressure (at the rotor) you must reduce the diameter of your M/C not increase it. The smaller M/C will give you a resulting higher line pressure as you will be exherting the same pedal force on a smaller cross sectional area. Your calliper piston bore sizes also influence pedal travel and applied effort.

Below is a spread sheet that I developed with John Alderson to give an indication of what combinations yield what line pressure outputs for a given pedal effort etc. I have only just added the pedal travel portion (may have a few gremlins). This prodominantly applies to a dual master system with a balance bar but you could use it for a single by putting the same M/C bore in for the 2.

As you will see, M/C size and pedal ratio will ultimately determine your line pressures and it's just a case of matching everything up. On the first sheet you need to put your wheel diameters, Vehicle mass, required deceleration force(G's) and the desired front to rear brake bias. Just punch in your proposed specifications on the second and have some fun

I might see if Simon will put it in the tech section when I'm sure it's right


Download Attachment: Brake torqueV2 comparrison.xls
29.7 KB

Thanks Simon.

I would assume there to be a proportioning valve of some sort in the rear drum circuit. So in theory , if the front brake torque and the bias front to rear was known, then the rear brake torque for the drums could be calculated. If the original proportioning valve was maintained then the rear torque would be the same irrespective of M/C size (although the initial force might alter until the line pressure reached the "knee" set point of the valve).
If the original proporting valve needs to be removed, I would stongly recommend replacing it with an adjustable one to retain the brake bias with a front brake or M/C upgrade. On that point, I would recommend a proportiong valve for the rear disc set-up also to raise the efficiency of the braking system at lighter brake applications.
Peoples comments / ideas are welcome [^]

What pedal ratio are you using - this may be the problem as the standard predal ratio may not be giving you the output you require (if that's what you're using).
What size piston bores does the Corvette calipers have?
2 pistons?

Mark,

With moderate pedal pressure you will need 1200psi + from your master to provide efficient braking.

Pressure = Pedal force / M/C area.

Your pedal ratio will have a direct relationship to the output of the M/C.

To be honest, with the 0.625 M/C I thought you would have plenty of pressure unless your caliper bores are quite small or your pedal ratio is not right. Either one will give you a hard pedal needing a decent push.

No Probs

OK, well this project has officially come to a close!

But, keep an eye in this section......