Deenasty

Does anyone know how much vaccum you need in order for your brakes to work properly? I am running a 240/240 595/595 112 lsa, and after the car warms up, I checked the manifold vaccum with a guage and it is only making 9"!!! I dont have any vaccum leaks to my knowledge. My car idles at about 925-950 (M6). My IAC counts are at about 77..I called TPiS, being they are the cam designers, they said to close my throttle blades a bit, and readjust the TPS. But wouldnt this raise my IAC counts?

Deenasty

anyone? Spinner? Mindgame? Injuneer? Shoebox?

BlownF1

I've got a somewhat similar combo and I'm pulling between 12 and 14 with less than 100 miles on the motor...brakes work fine.

Spinner

MY cam thats just a tad smaller then yours pulls just above 10" of vacuum. Brakes kinda suck dont they I know the feeling. Get a vacuum canister, it'll help a lot. They're pretty universal, and can be had for ~$50 from jegs or summit. Autozone might even carry them. If your still not satisfied, you can get a vacuum pump. Basically a little electric canister pump with a fitting. The brakes will run off of its vacuum, and not manifold vacuum. Most pumps can give ~20 lbs of vacuum, which is awesome, but some of them aren't cheap.

Blownf1: Your cam is a LOT smaller, and on a 114 lobe. Thats why you make vacuum.

Deenasty

BlownF1, your cam is a lot smaller than mine, and its on a 114 like Spinner said, thats why you have vacuum.

Spinner, are you using a vacuum canister? I was looking at Jegs, and they have one for like 34.00. I was wondering if you think I can benefit from this? The cars brakes seem to work, but just not like they use to. I talked to a tech at TPiS, and he said that if I am facing a vacuum problem, either my brakes would work, or they wouldnt. Does that sound true? I thought the less vacuum, the less stoping power, but I guess he said its a work or no work thing..

Spinner

I have the cheapy jegs canister on mine. Made a world of difference, though I'm considering putting a bigger one on it just because I can. The less vacuum, the less stopping power to a point. Basically thats because the master cylinder can only offer X psi of pressure per X vacuum. However, the amount isn't linear, its parabolic, and increases/decreases repidly at either end of the chart. Throw a canister on there, and see how you like it.

Deenasty

Hey Spinner, I got home, adjusted my IAC counts, and readjusted the TPS, and installed a thicker line from my bellow (After the MAF) to the intake manifold to allow more air..I rechecked the vacuum, and now its making 11-12"!!! But im still going to get a canister

RamAir95TA

I'm pulling 11.5" of vacuum with my cam, and it's just BARELY considered comfortable. I don't plan on picking up a canister simply because I'm comfortable with how the brakes feel.

Good luck with yours.

BlownF1

I know they're different...you hadn't gotten any replies at that point and I was trying to give you a point of reference in that mine seems fine at 12-14". If you can get to that range, I think you'd be fine.

Deenasty

thanks a lot, i will try to sweet talk her tonight, to see if she gives me more inches!!

rskrause

11-12" is the bare minimum for proper brake operation. A higher idle speed will help but a vacuum canister is often needed with that kind of vacuum and is a necessity if the vacuum is less.

Rich

1982z28with18s

I pull 16" at idle in park, 13" in gear, and 8" with the a/c on(drops my idle to 650rpms, but I will soon be fixing that). Even with the a/c on the brakes still work, just not that great.