How to properly size master cylinders? - Bias bar + manual conversion

[PerilousActs]

So, I've decided to go for a fully floor mounted pedal assembly with my current build. I'm going to be picking up a Tilton 600 series pedal assembly with bias bar and dual master cylinders for the brake system. Like so:
http://tiltonracing.com/images/3ped.jpg

Now, I know that properly determining the diameter of the master cylinders required for my setup requires caliper piston diameter and the number of them. For now, I'm running fully stock calipers all around and I'll be upgrading to Wilwood Dynalites in the future. So for now, I would like to get a setup that will work great with the stock calipers and learn how to determine sizing properly so I can easily do this in the future. How is this done?

From my understanding, I'll need a larger master cylinder set with the stock calipers than the larger ones since they require more pressure. Is this correct? If so, is something like a 5/8" or 3/4" enough?


P.S. Yes, I know Tilton will recommend a setup for you, but I have yet to hear back.

[Def]

It depends on how much force you want on the brake pedal and how much travel you can tolerate.

I do have to ask though, why Dynalites? Those are pretty meh calipers in the Wilwood line-up unless you absolutely want to save the last pound of unsprung weight like an autox setup. The Superlites are a much better line to look at. Bigger pads, stiffer caliper bodies... they look better too. hah

[onlydrinkkoolaid]

Can you explain why would you use this setup Im not familar with this just a little education

[Def]

2 master cylinders for the brakes(one for front, one for rear). The balance bar is a mechanical linkage that you can change the geometry to adjust brake bias front to rear.

[PerilousActs]

It depends on how much force you want on the brake pedal and how much travel you can tolerate.
Well, I'm used to driving manual brakes on my VW bus, so that helps at least. I'd say somewhere in a medium amount of force I guess. I know it's usually based on person preference but I need somewhere to start I guess.

I do have to ask though, why Dynalites? Those are pretty meh calipers in the Wilwood line-up unless you absolutely want to save the last pound of unsprung weight like an autox setup. The Superlites are a much better line to look at. Bigger pads, stiffer caliper bodies... they look better too. hahI like the fact that they help save on unsprung weight as you said, but I'm not 100% decided on them yet. I've been looking at the Arizona Z Cars big brake kit as well. Or possibly even going EVO Brembos.

[Def]

Well, I'm used to driving manual brakes on my VW bus, so that helps at least. I'd say somewhere in a medium amount of force I guess. I know it's usually based on person preference but I need somewhere to start I guess.

I like the fact that they help save on unsprung weight as you said, but I'm not 100% decided on them yet. I've been looking at the Arizona Z Cars big brake kit as well. Or possibly even going EVO Brembos.

EVO brembos and a stock rotor is HEAVY. Like 16-18 lbs heavier than a 30mm Z32 setup(which is very heavy for the size).


Dynalites will not fare well for track use(is that what you're doing with these?). They might be ok for drift usage, but the small pads are not going to last long.

The AZ Z-car setup is $$$$ in consumables(rotor rings are near $200 ea), and it uses the wussy Dynalites.


I'm working on a Forged Superlite setup(hats + brackets) utilizing the cheap 12.2" rotor rings that circle track guys use($40/ea). It'll save about 18 lbs over an aluminum 30mm Z32 setup up front and be fully capable of track abuse. Planning on a GB soon.

[Def]

Forgot to add, the FSL-4 setup I'm working on will be cheaper than Wilwood's kit using the same calipers. Consumables will be way less given $40 rotor rings and cheaper pads that are also larger than all Z32/Z33/EVO/STi calipers. Let the circle track guy's buying power work for you.

[PerilousActs]

EVO brembos and a stock rotor is HEAVY. Like 16-18 lbs heavier than a 30mm Z32 setup(which is very heavy for the size).


Dynalites will not fare well for track use(is that what you're doing with these?). They might be ok for drift usage, but the small pads are not going to last long.

The AZ Z-car setup is $$$$ in consumables(rotor rings are near $200 ea), and it uses the wussy Dynalites.
Valid point, I haven't looked into the weight on the EVO stuff at all yet and true about the AZC setup. This is for a track car, yes.


I'm working on a Forged Superlite setup(hats + brackets) utilizing the cheap 12.2" rotor rings that circle track guys use($40/ea). It'll save about 18 lbs over an aluminum 30mm Z32 setup up front and be fully capable of track abuse. Planning on a GB soon.
I've been looking at this stuff as well. Lots of parts in abundance second hand on ebay from race teams. I would like some info on that for sure.

[onlydrinkkoolaid]

Thanks for the lesson I guess its time to do some serious research

[GenPac]

Read this PDF from StopTech.

http://www.stoptech.com/tech_info/PedalSetup-DualMaster-Guide.pdf

Ideal M/C bore size is relevant to your pedal ratio and caliper piston surface working area. The larger the bore, the more volume you'll have for the calipers but you must offset with more leg effort to get line pressure. The smaller the bore, the higher line pressures you'll have with less leg effort, but if you have large single pistons (+2.9" bore) or many medium sized (2") pistons you will run out of pedal travel due to a lack of volume to fill and push all of the pistons.

Clear as mud? :naughtyd:

[onlydrinkkoolaid]

Holy crap just read over that stoptech link. I never new all this went into brakes geese I was good until about the last page when they started throwing all these formulas to MC size and MC volume geese... Thanks stoptech somebody has to take on this madness

[Otto347]

Im running manual brakes on my car with the wilwood dual pedal setup. I just told wilwood what calipers and rotors I was running and they suggested the bigger pedal ratio (I believe its the 6.2/1) and 7/8" front and rear master cylinders. I have Superlites up front with teh Z33 track rotors and will have the dual piston nissan calipers in the rear with stock rotors.

[smracing]

I have the same pedal setup in my s13. 3/4" clutch, 1 1/8 front and 7/8 rear. Dynalite singles in front, q45 rear.

[GripTerror]

Def they come with dynapro not dynalite i dunno what the site has listed up there. The front 6pot is lighter than the z32 setup i had and larger/thicker rotors. They are costly replacements but yup.

I want that Tilton 600 series pedal assembly so badly.

[Def]

Def they come with dynapro not dynalite i dunno what the site has listed up there. The front 6pot is lighter than the z32 setup i had and larger/thicker rotors. They are costly replacements but yup.

I want that Tilton 600 series pedal assembly so badly.

About the same thing - tiny pads either way. I could have sworn they were forged Dynalites though.

It's not hard to beat a Z32 setup on weight. My kit has 1.2" larger dia rotors, same width, and saves close to 20 lbs over an aluminum Z32 setup while using larger/cheaper pads.