Technical Brake Questions?!

[IronFreak]

I'm going to be running manual brakes in my build and I have been looking at the Tilton and Wilwood assemblies. Obviously with manual brakes it's going to take a little more strength to get the car stopped. Both companies offer different ratios on the overall stroke, but I guess I'm confused as to what I should go with.

Example, Wilwood offers a 6.25:1 and a 5:1 ratio. I understand that with the 5:1 there will be less overall movement of the pedal to fully lock the brakes. But will the depression of the pedal be that much harder as well?

My Second question that might have an effect on the first would be, does the bore size of the master cylinder have an effect on this as well? They offer multiple bore sizes, what is the benefits from small to big? Does a bigger bore offer more pressure at the cost of a more difficult depression of the pedal?

This is my first time of venturing into this world of after market brakes, I think I have a decent understanding of whats going on, but a little light to these issues would help clarify a few things.

Thanks!

[Mako18]

Pedal ratio for reference stock is 4:1

Stock master 17 mm= .669/22mm =.866
Basically 11/16 and 7/8

Bore area increases, thus you will have to move more fluid thus requiring more effort. Your pedal travel will also decrease since you move more fluid area in the same travel length.

Force = Pressure X Area.


Look here:

http://www.e30tech.com/forum/showthread.php?t=116285

See post #7 here:

http://www.e30tech.com/forum/showthread.php?t=113105&highlight=pedal+ratio

CLIFF NOTE'S:
Assuming your on stock brakes or rx7 setup. This does not take into account vehicle weight, increased hp/tq, high performance break pads etc etc.

You will want the following:
6.25:1 pedal ratio (remember your booster less now)
5/8 bore brake master cylinder front and rear (dial in the balance bar)
adjustable bias valve inline for "fine tuning"
Choose proper pads.

[IronFreak]

Pedal ratio for reference stock is 4:1

Bore area increases, thus you will have to move more fluid thus requiring more effort. Your pedal travel will also decrease since you move more fluid area in the same travel length.

Force = Pressure X Area.


Look here:

http://www.e30tech.com/forum/showthread.php?t=116285

See post #7 here:

http://www.e30tech.com/forum/showthread.php?t=113105&highlight=pedal+ratio

CLIFF NOTE'S:
Assuming your on stock brakes or rx7 setup. This does not take into account vehicle weight, increased hp/tq, high performance break pads etc etc.

You will want the following:
6.25:1 pedal ratio (remember your booster less now)
5/8 bore brake master cylinder front and rear (dial in the balance bar)
adjustable bias valve inline for "fine tuning"
Choose proper pads.

Brake calipers will be a custom setup that will either be like the rx7 or similar Wilwood calipers, either way they will be 4 piston calipers. And what about the clutch side, I saw that Wilwood made a setup that has the 6.25:1 brake ratio with the 5:1 clutch ratio. If I go with a hydraulic clutch setup that would work ok wouldn't it?

[IronFreak]

I was thinking about upgrading the braking system and using these. The piston is 1.75, not 1.38....What would that do to the pressure, could I up the bore size on the MC?

http://www.speedwaymotors.com/Wilwoo...tor,24241.html

[Mako18]

If you do I have two 3/4 HOWE in the f/s section . You need to play with a brake calc.

[dmoney(AB)]

I'm running the wilwood pedal setup with 5/8" masters and have found it isn't enough to stop the car.
I tried adjusting the bias bar all the way to the fronts and still couldn't lock them up.
Looking to upgrade the brakes to something larger.

[Mako18]

Your on stock brakes?

[IronFreak]

I won't be. I'll be using Wilwood hats, 11.75x1.25 rotors with dynalite 4 piston calipers..... tentatively...

[Mako18]

I won't be. I'll be using Wilwood hats, 11.75x1.25 rotors with dynalite 4 piston calipers..... tentatively...

Massive kit?

[IronFreak]

Massive kit?

No, but the same specs, just cheaper......

[dmoney(AB)]

Yes I'm on stock brakes for now.

Hit me up with where your getting your parts from ironfreak

I've been waiting for a massive kit to surface in the marketplace but have no luck!

[Mako18]

What ^^^^^^^ said.


A gb would be sweet from one of the vendors. Just sayin cough uhum cough

[dmoney(AB)]

Bump?

[IronFreak]

Hang tight, i need to get my struts back together and take a few measurements. Once i have that and i know what I'm thinking will work ill post up information.

[dmoney(AB)]

It's getting close to being nice enough that I
Can drive the car but I want this brake issue fixed before I get in traffic.

I've been looking at going with the ie 310mm front and rear kits and have been given the following info from ie:
front -- each side if caliper has 3 pistons -- one at 41.1mm & 2 at 28.4mm

rear -- each side of the caliper has 2 pistons -- at 31.8mm

Trying to figure out if these caliper pistons will be sufficient