any one have power brakes on a pp 13b?
if so how are you doin it?
i was thinking of taping my intake and running a "T" into both of the runners to get power brake but im hopin there is a better way, anyone run a pump off the pulley? or how bout taping the header with a check valve??

 

Why would you want a check valve? I assume it doesn't have a turbo?
Yes, just make a connection after the throttleplate, doesn't have to be on both intake runners, just one connection on one intake runner is fine. If the intake runner is made from something thickwalled you can tap it and insert a fitting of some sort. Otherwise you can weld on a connection. Brake boosting is going to be a bit less though since PP's don't pull that much vacuum. An extra pump would make things too complicated if you ask me.

 

no turbo, carb'd

a check valve so it doesnt back feed.

 

my answer is lame... i notice ALL the MFR intakes just have a normal fitting for the brakes, just like a stock intake.

the non answer part? when we made my intake, we didn't plumb a brake fitting, i sort of planned to get the car running and then get to it, but an 82 Rx7 doesn't NEED power brakes! pedal effort is totally reasonable, in fact its about like a stock BMW. i've done track days too.

i know an FC does need power brakes though, tried it. i would just plumb the brake vacuum line like stock, that's how mazda did it on the race cars....

 

Pull from only one side. Put a check valve as close as possible to the manifold.

My FB needs power brakes.

 

Piston guys running really large high overlap cams sometimes use electric vacuum pumps like this one rather than relying on engine vacuum.

http://www.summitracing.com/parts/HLA-009428087/

 

A brake booster reservoir would work too.

 

A reservoir would help but I'd still use a vacuum pump with the reservoir. Just keep the pump on a vacuum switch.

 

You learn to blip the throttle a lot... it's not to sound cool, it's to build vacuum so the power brakes work

Kevin, you remember the neighborhood where we were at the secret dyno session? Remember how far it was until you got to a 45mph road? I didn't have power brakes until after I got on that road... don't like to go over 2000rpm in town!

 

All the way near the highway with the old rundown plant?

yikes...

BTW what did yours end up putting down @ what RPM?

 

140 at something like i don't know but the torque curve was falling FAST after about 6000rpm. Exhaust is way too restrictive.

But over 130 from something like 6000 to something like 7500... so the HP curve is flat up there, anyway.

Yeah I'm disappointed! But this just confirms what i already knew: six-ports suck.

 

If you have the money to do it, Id go with an electric vacuum pump system. Then you know you'll always have good consistent braking. If not, you can just tap into the intake manifold. I started with a tap just into one runner of the intake manifold on my Rx-4. The brakes were not that great so I made a little manifold to join to the other runner and I noticed an improvement in the brakes. My Rx-4 is only a half bridge port, but it also idles at 1000rpm so it doesn't pull a whole lot of vacuum at idle.