I finally got around to installing my boost gauge..

At idle it sits around 10hg vacuum..

I didnt get to do a WOT run because its leaking and that explains the 3-4psi at pretty hard throttle...

After I let out of it, it drops to around 8 and then to 11 hg vacuum...

Is this right.. or does it sound right?

 

To only have 10" of vacuum at idle you must have a fairly large camshaft. If not, then maybe a kinked boost line to the gauge or it isn't installed in an area that has full manifold vacuum.

I get 14" of vacuum in gear with Stage II cams on my Lightning. 12" in gear with the A/C on. Even with these cams I still show 18-20" of vacuum when I remove my foot from the pedal to coast to a stop.

Where are you hooking the boost gauge to?

Jody

 

My cam is 212-218-522-529-114

also I have no cats, or mufflers... and a cutout

 

I just went out and checked mine. I'm running just a hair over 16" vacumn at idle, if I blip the throttle it will go to 20 when then engine idles back down then return to around 16-17 vacumn. This is on a 6.0 with a whipple, little larger cam than you. Some head work, long tubes,no cats, 3inch y-pipe to 3.5 inch single magnaflow dumped.
Where are you hooking up your boost guage line?

 

Yeah... I think thats the problem....

It said tie into a manifold Vacuum line...

But I talked to YellowSierra and theres a place where the throttle body used tobe where it has a place to hook it up.....

Im goign ot put it there tommorow.... and see if anything changes!!

 

My 5.3 with Radix is about the same.

 

where is the boost leak?? if you have a boost leak it could suck vacuum through there if your boost gauge is before the leak the you won't show as much vacuum.

 

I am going ot try and put it in the front of the intake manifold, where the supercharger meets it..

and I wil lhave some more results!

 

cool where is the leak??

 

Pretty sure mine is around 16-18 at idle.