Willwood New Clutch and Brake Pedal Set - Ratio Choice Qustion

[Ducs]

I've just noticed that Willwood released a new forward mount tandem master cylinder brake and clutch dual pedal assembly that would work well in my application. I need advice on the ratio choice. 340-14360 is a 6.25:1 and 340-14361 is a 7.00:1



I will be running a Wilwood 260-9438 7/8" tandem master cylinder, manual setup, with C6 Z51 calipers and rotors, front and back. Should I got with the 6.25 or 7 ratio pedal ?

Thanks in advance

[65 drop top]

Sorry I can’t help you specifically with your set up but I’ll tell you what I have and maybe it’ll give you an idea for what you might need. I have a 5.40 piston area up front and 3.56 rear with a 15/16” Wilwood manual master and have the 6.25:1 Wilwood pedals. The system should produce somewhere around 3900 #’s braking force. This is based off of Ron Sutton’s recommendation. I purchased the pedals from him as well. Give him a call he’ll get you set up.

[Ron Sutton]

Sorry I can’t help you specifically with your set up but I’ll tell you what I have and maybe it’ll give you an idea for what you might need. I have a 5.40 piston area up front and 3.56 rear with a 15/16” Wilwood manual master and have the 6.25:1 Wilwood pedals. The system should produce somewhere around 3900 #’s braking force. This is based off of Ron Sutton’s recommendation. I purchased the pedals from him as well. Give him a call he’ll get you set up.

I'll add to what 65 drop top said,

It is all about the combination of pedal ratio, piston bore sizes, rotor diameter & pad compound (COF). If you will post your piston bore sizes front & rear, current M/C size & specifically what brand & model of pads you're running, I can help you pick a ratio.

You already listed the M/C size of 7/8". Provide piston diameters & pad compound please.


P.S. To everyone following along, the 3.56" piston area for 65 drop top's brake system wasn't ideal. Typically with 5.40" front piston area Aero6 calipers (What 65 Drop Top has) I like to run 2.46", 2.70" or 3.00" rear piston area. But Wilwood only offers the Aero4 (what 65 drop top wanted to match the look of the front) in 1.98" or 3.56" versions. Our plan is to lean on the rear proportioning valve pretty heavy in his combination to a balanced braking system.

[Ducs]

Ron, Thank you for chiming in.

Caliper piston diameters are:

Front - 40.5 mm x 2
Rear - 42.5 mm

Rotor diameters are:

Front - 340 mm
Rear - 330 mm

Master cylinder 7/8", manual

I haven't looked into brake pads yet, I am still far away from pad selection for my project.

Thanks,

Matt

[Ron Sutton]

Ron, Thank you for chiming in.

Caliper piston diameters are:

Front - 40.5 mm x 2
Rear - 42.5 mm

Rotor diameters are:

Front - 340 mm
Rear - 330 mm

Master cylinder 7/8", manual

I haven't looked into brake pads yet, I am still far away from pad selection for my project.

Thanks,

Matt

Hey Matt !

With those calipers, rotors & 7/8" M/C ... and a good .40 CoF Pad ... you need the 7-1 pedal set.

The 6.25-1 pedals will only create 2388# of braking force.
The 7-1 pedal set will create 2675# of braking force.

Frankly, both of those numbers are kinda weak.

[Ron Sutton]

Here is the guideline I use

Total Braking Force Guidelines:
2500# = Average passenger car
3000# = Performance production car
3500# = Good street & track braking system with big tires
4000# = Track braking system with big tires
4500-6000# = Full race brake systems with serious downforce & slicks

[Ducs]

Fantastic !! I really appreciate the express response Ron !! Thank You very much !!