Torkmnstr
Member
Hey all I need to get some opinions on a brake booster assist system. I have discs on the front but the cam isn't pulling enough vacuum to keep a firm petal. Thanks. Tom
What brake booster assist to buy?
- Thread starter Torkmnstr
- Start date
Ranger
Well-Known Member
How much vacuum ARE you pulling? The cam I just swapped out was lucky to pull 3" at idle. Fortunately, I am not running power brakes.
Torkmnstr
Member
Ranger not sure what I'm pulling, the motor is out of the car at the moment. But it is an isky 280 mega cam, .485 lift, 108 centerline.
quikbird
Well-Known Member
They make a electric acuum pump to help with this. I personally run manual brakes and haven't needed one, just thought I'd toss that idea out there. :cents::cents:
Torkmnstr
Member
Nice quick, I think I will go with that option.
Ranger
Well-Known Member
You know, I don't remember the spec's on the cam I removed, but your numbers sound somewhat familiar. I think you are probably similar and would be surprised if you where to put a vacuum gauge on it. I'll bet it's not the quickest starter either. I know mine took some cranking to lite it off. Not surprising with that little vacuum. Now she comes alive pretty quickly. If you are sticking with that cam, I think an electronic vacuum pump would be a wise (if not the only) choice.
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Torkmnstr
Member
Ranger it actually started pretty quick, but I will defiantly need the vacuum pump since I to am swapping my cam to a custom ground hyd roller somewhere in the .600 lift range.
Ranger
Well-Known Member
I'm no expert, but I don't think lift affects vacuum and starting as much as overlap and thus center line. Low vacuum while cranking = little draw through the carb, thus little pressure drop in the venturi and thus little or no fuel draw equaling long crank times. Sure proved true in my case although I do have to admit that I may have had some choke adjustment issues as well which may have contributed.
Torkmnstr
Member
I can see your point there.