LT1ponykilla

Im trying to find out how much vacuum you guys are making with the same cam as me. Im running this cam on a 112 LSA and only making between 8.5-10.5''s of vacuum. Thanks.

LT1ponykilla

ttt

Juiced Impala SS

My cam is on a 114 LSA and in my 383.... but I'm getting 16-17" of vacuum at idle and about 22" in overdrive going about 65 mph.

LT1ponykilla

Thanks man. Anyone else?

S.J.S.

where and how do you test the vacuum????

Fastbird93

Ditto. I've never done a vaccuum check before and could stand to know where I'm at. FYI, I'm on a 112 LSA also.

Perry93TransAm

My car pulls 18 at idle with that cam. But I am running a 383 too.

Chris 96 WS6

I have the stock shortblock with the 224/230 XE cam with a 114LSA.

I typically see 47-50kPA on the MAP and 17-17.5" on a vacuum gauge.

Something is wrong if you are only seeing 10".

Check for vacuum leaks at the various hoses, leaks at the intake manifold gaskets, and also check valve adjustment. A really really poor tune can do it too...if its running so rich it doesn't want to idle then it will likely not have much vacuum either. I found that going to about 28-31* of closed throttle timing advance increased vacuum and decreased idle fuel consumption too. Its not going to help enough to cover the big vacuum deficit you have but once you get the big problems sorted out it is something to play around with.

unTAmedLS1

Im seeing about 16 on a 112 lsa you definetly have a leak somewhere

LT1ponykilla

I dont think I have a leak cause I sprayed some WD-40 around the intake and places and it never changed my idle. I think my timing chain isnt set dot to dot. Thanks for the help guys.

S.J.S.

aw cummon guys.....just posted how do you test the vacuum. 3 more posts come up and say they got 16 and 17psi but no one says how to do it.

thanks

PoorMan

I just plug the hose into a vacuum port on the plenum. I use the port that use to go to the EGR. Start the car. Read the gauge.

Jeff D