Boost while no engine load question
Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 1,172
Likes: 71
From: MA
Boost while no engine load question
I just finished a Procharger install. I haven't had it tuned yet but wanted to see if I was getting any boost. I slowly brought the RPMs up to 3k while in neutral and noticed no boost. My boost gauge is still reading about -10 psi. Is this normal? I thought that I should see some boost!
I don't have any belt slip. I was wondering if my surge valve is operating correctly. Since my engine manifold is still under vacuum, is the surge valve preventing any boost? Does it open under vacuum to prevent boost??
I don't have any belt slip. I was wondering if my surge valve is operating correctly. Since my engine manifold is still under vacuum, is the surge valve preventing any boost? Does it open under vacuum to prevent boost??
Former Vendor
Joined: May 2005
Posts: 3,749
Likes: 4
From: Valencia Ca
The blower can/will make pressure in this scenerio but the motor will simply ingest the air and push it through with little effort as RPM acceleration is not significantly restricted - i.e., there is in effect no load.
When you are in gear (4th gear as an example) note the difference in time it takes to rev from 1500 - 6500 - that's load/work at play and RPM is now accelerating at an entirely different rate.
With the engine now loaded, and RPM acceleration slowed, the result is that the compressor is now able to pump air at a rate and volume higher than the motor can push through and hence, boost pressure.
When you are in gear (4th gear as an example) note the difference in time it takes to rev from 1500 - 6500 - that's load/work at play and RPM is now accelerating at an entirely different rate.
With the engine now loaded, and RPM acceleration slowed, the result is that the compressor is now able to pump air at a rate and volume higher than the motor can push through and hence, boost pressure.
I just finished a Procharger install. I haven't had it tuned yet but wanted to see if I was getting any boost. I slowly brought the RPMs up to 3k while in neutral and noticed no boost. My boost gauge is still reading about -10 psi. Is this normal? I thought that I should see some boost!
I don't have any belt slip. I was wondering if my surge valve is operating correctly. Since my engine manifold is still under vacuum, is the surge valve preventing any boost? Does it open under vacuum to prevent boost??
I don't have any belt slip. I was wondering if my surge valve is operating correctly. Since my engine manifold is still under vacuum, is the surge valve preventing any boost? Does it open under vacuum to prevent boost??
