Hey Guys,

I'm building an FD race car and I'm trying to eliminate the ABS system. I'm wondering if anyone here has had any experience with doing this. Anything to watch out for? Best way to get the balance close?

Thanks,
Kyle

 

I personally don't have experience with it but there have been a few threads here in this section as well as the Suspension / Tires /Brakes about this. Might want to do a search.

 

Yeah I did....

I'm already going with Stoptech... my entire package has been designed... my questions are about what size master cylinder to go with, and who has had track experience without the ABS system and other issues related.

Kyle

 

I would start with (2) 3/4" MC's and experiment with the balance bar. The pedal will take more force to stop, since you no longer have the power assist. this takes some getting use to but it is not impossible. If the force need by you is to great for your taste then switch the front master with a smaller diameter like the 5/8". it will take some time and experimentation to get the right feel.

 

Call me a newbie, but shouldn't a smaller master cylinder increase the pedal effort? I mean, my understanding is that the bigger the bore of the master cylinder, the more fluid it moves per the same pedal effort. Is that inaccurate? Trying to fine tune this myself and slightly confused by it all.

For example, after talking with Tilton on the phone today, if I wanted to move the engagement point of my clutch pedal further towards me, one solution would be to move to a bigger MC bore (currently using 5/8", tech guy suggested 3/4").

 

Newbie! Sorry, you told me to say it.
A bigger master will increase pedal effort. It moves more fluid than a smaller one for every inch of travel that is why it will change the pedal movement amount. If you look at the square inches of surface area compared with a small one you end up with LESS hydraulic advantage with a bigger one, thats what makes the pedal harder.

Usually you will end up with a smaller master on the fronts than the rears if you are running a bias bar set up.

 

I filled out the Tilton questionnaire thing as to what MC sizes to be used and they responded saying that I should use a 7/10" front and 5/8" rear which is pretty much contrary to all advice given here for a stock FC braking setup - all posts I have read here say that you need a 5/8" front and 7/10" rear. Any ideas why?

 

That does seem odd. Maybe that'd be good for larger front brakes and stock rears, but the stock system uses the same size MC for both (shared) and then the rear pressure is reduced, so you would want a larger rear MC without that proportionning valve to give you a lower rear line pressure.

 

I guess for simplicities sake why not just leave the stock prop valve in place and use 2 of the same size MC's?

 

I guess if the balance is close enough with the stock setup, why not right?