I posted this on the engine tech board by accident and didn't get any reply. I'm re-posting here because its the right board.

I have a set of brodix heads on order. I'm in the process of rebuilding my motor and with the bigger cam I am putting in I will be loosing power to the booster.

Who here uses an electric vacuum pump for their brakes? How do they feel? Is the braking the same?

Also my alternator is under-driven because I really have little to no electronics in the car besides, gauges, fan, headlights/taillights/signals (I rarely run at night and they are just there to be legal) Will I need to run a standard pulley on the alternator to use this or will it be fine with it under driven. I think I produce somewhere around 13.5v at idle and 14v at 3000+rpm not much less than a standard pulley.

Also are there any better alternatives to the electric pump? I was going to go hydro booster but its a little more involved than I wanted to get.

The mechanical race pumps are nice also but they are a little on the expensive side when it seems as if all I need is the electric pump.

 

what cam? do you really need the pump?

 

I spoke to a tech at comp and he said I would loose vacuum to the booster and it might make the brakes hard to push. Its a XR294HR under brodix IK200's and a VICJR. Its .540/.562

 

You're right....if your new camshaft reduces the pumping loss in your engine, it's like going to altitude - you'll need a supplement. However, I think I'd do leg exercises before adding a vacuum pump. Consider modofying the attachment point where the master cylinder pushrod attaches to the brake pedal...this will increase your mechanical advantage of your brake pedal inputs. Don't go on the cheap though...be sure to make the re-attachment with confidence!

 

blackbmagic,
I'm only getting 10 psi at idle with the cam I have and a D1SC, so it seems we are in the same boat. Jegs and summit have them but they start in the upper $200 range. I'm going to keep searching and I will post any good info I find.

Steve

 

Try a vacuum canister/resevoir.

 

Like the man said install a vacuum canister/resevoir that should fix it. I but one on my 69 camaro w/427 and a very big roller cam it worked. I only have 4 PSI vacuum now my power brakes work fine. I have C5 corvette all around.

 

i have a electric pump on mine , its has a vortec 350 with lt4 hot cam and it doesnt work so good if u are breaking again before the pump pulls the vacuum again. This really took the fun out of working on my car. I replaced all the breaking system except the hard lines and pp valve. Cars been sitting for years and im going to give it another try since my ss needs a new motor.

 

How do you hook up the reservoir? I have a black plastic basketball sized sphere that has vacuum lines that aren't connected. Is this a reservoir?