Just noticed tonight guys, but on my boost gauge when i give my car part throttle slowly increasing RPM's my vaccum gets less, but as the RPMs are rising my car starts to pull more vacuum. If i have a load on the motor in gear and moving at part throttle increasing RPM slowly there is no vaccuum, but why would my car pull vacuum in non gears part throttle with RPM rising slowly?? Vacuum leak somewhere or what??? maybe its done this all along, Ive just started watching my gauges and stuff more recently.

 

 

I believe with no load and at part throttle the wastegate is wide open and the bov is recirculating the air so there isn't any real pressure to the manifold so you'll see vacuum since engine is sucking more air as rpm rises.

 

kool, thanks, just curious...will someone do like a test or something in their driveway just so i can have a peice of mind with this issue,then i can just focus on my main 1 problem.

 

The cams will lower your vacuum reading at idle~ 15-17 in, once you raise rpms to 1200 your no load vacuum will increase back to 20-22 in. This is how it is on mine w 264/272

 

Thanks, i was just curious....was suprised no one else noticed this.

 

I run a slight vacume at idle and in neutral, but i doubt the accuracy of my boost gauge...it's off by 2psi anyway.

 

doesnt everyone??? lol