Anybody here using an electric vacuum pump for braking booster vacuum?? I am considering the one from Godman Performance. I hear these pumps are loud but will produce a constant 21 in. of vacuum which I definitely need. Any opinions?? I know all about the Hydroboost. That would be last resort. thanks, Nick

I too would apreciate some info on this...

Why do you think you need 21"?

I have a dual diaphragm and 10" at idle and it works fine.

Another possibility for you might be a vacuum reservoir. Or an electric version of hydroboost that GM used on some cars/trucks for awhile.

Having tried all the options myself (vacuum tank, electric pump, and hydroboost) let me suggest you rearrange your priorities to have the hydroboost as your first resort rather than the last resort. It is the most effective option out of all of them, by far!

If you want to run an electric vacuum pump, GM used them on some of the "small cars" in the 80's/90's, the Pontiac Sunbird comes to mind. You need to use a vacuum tank with them to cut down on the pump cycling, but they do work.

The electric booster (the Powermaster unit which GM put in the Grand Nationals) can be problematic and costly, I would suggest you pursue other options. Most GN guys convert to vacuum brakes or a hydroboost and ditch the powermaster at the earliest opportunity.

What brake setup does you car have? If you have factory discs/drums, a 15/16" bore manual master cylinder works great. That would be the easiest and cheapest option by far. The pedal effort is not that great.

Troy

Troy, I have factory front discs and I have just now added Wilwood rears. The car has factory power brakes with a new booster an master I just purchased a year ago. I'm hoping to keep that set up. I just need more vacuum since I have a 540 with a big cam. I only have around 7 -10 in vacuum. So my situation is this...over 800 hp street car and no brakes!!
I know all about the Hydroboost. I wish Hydroboost would conceal that device in a factory looking booster! I would definitely go that route! I may suggest that to them. In the meantime, I'm gonna try the vacuum assist way....I think.

Vroom3440, I dont think I need 21 in. vacuum. Thats just what I heard you get from those electric pumps. I think all I need is about 16 for any kind of assist from the booster.

Nick

Hmmm... your vacuum numbers are not that different from mine presuming we are using the same idle reference point. I sit right about 10 until the cooling fans kick on and then it can drop, sometimes down to as low as 5". My idle is a bit irregular as well. But all told I still have plenty of boost and can lock the brakes.

But that is really worst case. In the most typical scenario I have much higher vacuum as typical braking starts with higher engine RPM and closed throttle where the vacuum numbers are much higher.

I have wondered about the vacuum reservoir approach and had thought I might need one myself. Had been looking at a Becks mini beer keg to fabricate up a tank with :-) How effective are vacuum reservoirs?

I can also vouch for the Hydroboost as I have one on a late model Mustang GT as my daily driver. It is a very confidence inspiring braking system. One factor that is not mentioned much but in practical use is huge is the brake system response time. The hyrdoboost requires much less pedal travel before boost is enabled so you get braking much sooner on pedal application. I would like to have put one on the El Camino irregardless of whether it looked original or not (somebody long before my time committed this one to the modified path rather than the restored path). But the cost was a deal breaker.

I also had planned to run a GM Powermaster, got the booster and MC even. But then I decided I did not really want to run the required electrical wiring even though it really wasn't much. Anybody want to buy an unused Powermaster rebuild unit?

In the end I wound up grabbing a dual diaphram booster from a 79 El Camino for valve cover clearance. Install was pretty straightforward and it seems to be working well. But the Hydroboost would have been sexier B-)

Vrooom3440,
You really got my head spinning now! Now I'm startin to think about the hydroboost again! At this point the cheapest and easiest route would be the electric pump though. So thats what I will probably do. I might just take a trip to the Hydroboost company too. He is just around the corner.
I like your mini keg resevour idea!! the best part will be emptying it!! I heard from a friend that has one that they do work but he has a relatively mild cam in his Mopar.
Nick

You just might be able to put together a hydroboost system by shopping at your friendly local purveyor of previously owned auto parts... I have seen a number of them in the yard. You would probably have to have a pretty good idea what you were looking for and have hoses made up.

Many (most?) of already have the hydraulic pump in place (to run our power steering), all we need are lines to plumb in the hydroboost.

I use the electric vacuum pump and reservoir out of a Volvo turbo car. It comes with a wonderful isolation mount to keep the noise down, and the elongated reservoir fits nicely in the dash of my 64 Nova, and it keeps the vacuum above 15" at all times, usually 20". They also have a high flow check valve in the system, so you can use the engine vacuum as well.

Took mine off bolted master to top two studs used brake push rod of manual brakes they are adjustable works great. YOU must remove brake light switch bracket and round house with push rod hole. Wish I had done this years ago, what could be cheaper and it works great.. Try it Bob