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rx7freak13v 11-15-16 10:50 AM

Manual brakes
 
Hey guys, i have been doing a lot of research on converting over to manual brakes on my 86 na fc and have been coming up very dry for the most part.

I have been considering doing this conversion because i am building a 4 port big bridgeport and high overlap and power brKes don't usually work best together.

My question is, what size master cylinder feels decent with the stock pedal ratio? I am debatin between 3/4" and 7/8"

Is it possible to adjust the ratio on the stock pedal? How?

Any info is very much appreciated

Jspaid142 11-15-16 01:40 PM

Look into the vacuum canister / pump route. Coming from the world of big cam LSx engines, that was the solution for when you have a monster cam and no vacuum at idle.

I wouldn't ditch power assisted brakes, and I'm a huge fan of no driving aids.

rx7freak13v 11-16-16 06:47 AM

Thank you for that response, i have never sern ot heard anything about the vacuum canisters. I did some quick searches and they are even fairly cheap for that matter under $100 for some good brand names.

Jspaid142 11-16-16 09:02 AM

Definitely do your research on it, I never personally used one but plenty of friends with their big cam V8s have used them with success

Whizbang 11-16-16 10:05 AM

having actually use manual brakes. It's not as easy as you'd think.

First, you will want a dual master if you do. You need to be able to better control the bias, and this is the way to do it. It be can further fine tuned with the balance bar and perhaps a prop valve.

Even then, the stock arm can only have the pivot point moved up so far and still results in a lower than preferred ratio. Second to that, the effort required for braking is considerable in comparison to the booster. Takes time to get used to it and develop the fine muscle control. Still takes more time to get used to technical braking.

That said, you can probably get away with the booster, check valve, and the vacuum canister as previously stated. The motor still pulls some vacuum.

Whizbang 11-17-16 06:07 PM

1 Attachment(s)
i modified the stock pedal as such. Granted this was for an FB but the idea is the same.

Unless the arm of the FC brake pedal is Aluminum... .I don't recall. If that is the case. Not sure what to tell you.


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