Brake Bias and prop valve questions for road racing - - Mazda RX7 Forum

Go Back - Mazda RX7 Forum > Tech and Performance > Race Car Tech
Reload this Page >

Brake Bias and prop valve questions for road racing

Race Car Tech Discuss anything related to road racing and auto X.

Brake Bias and prop valve questions for road racing

Old 02-14-19, 12:22 AM
Rotary Freak
Thread Starter
iTrader: (6)
Monsterbox's Avatar
Join Date: Jun 2006
Location: Birmingham, Al
Posts: 2,869
Thanks: 0
Thanked 31 Times in 22 Posts
Brake Bias and prop valve questions for road racing


Currently setting up the car for the racetrack. Road Atlanta, Talladega small track, and Barber Motorsports

The setup will be:
Brembo F50 4piston front brakes on 345mm rotors, ducted with 2.5in duct to custom backing plate
OEM rear brakes
Wilwood Dual Reservoir Manual Master Cylinder

I've read that the fd3s is inherently 68% front biased from the factory. I see people running prop valves, on abs delete kits, but the prop valve is typically placed on the rear line. So to me, it would mean that slowing off the rear brakes would give even more front bias. So then the general desire around here is that drivers wish to have less rear brake on oem brake setups? The driver and team we are working with only has experience with bias bars and true dual master cylinder setups so using a prop valve is new to all of us

when we move to the larger front brake setup, with larger pistons, this should dramatically increase the front bias. Would it not make more sense to run a prop valve on the front brakes, so as to help calm the front brakes down and overcome this bias of upgraded fronts? Or better yet should we consider running front and rear prop valves?

the platform is a 4 rotor turbo engine, overall weight is 2900lbs, 50 50 distribution, 14kg front 12kg rear spring, 3 degree front camber negative 2 degree rear negative. 250/640 and 280/680 yokohama slicks, and approximately 1000rwhp through a 4 speed dog box

What are you guys experiencing with upgraded front brake kits and bias?

Our goal is to be able to keep the rear brakes heavily active but not lock up, so that we can trail brake. And be able to dial in and out on the track. Depending on the bias, pad friction front to rear type will be chosen to aim for ideal ratio. We just havent had any experience in this car to get an initial game plan.

Monsterbox is offline  
Related Topics
Thread Starter
Last Post
08-10-10 10:41 PM
Race Car Tech
09-16-08 02:43 PM
1st Generation Specific (1979-1985)
11-08-06 02:36 PM
2nd Generation Specific (1986-1992)
03-22-04 12:40 PM

Thread Tools
Search this Thread
Quick Reply: Brake Bias and prop valve questions for road racing

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: