LS7 Carb intake manifold pressure drop?
Thread Starter
Staging Lane
Joined: Aug 2005
Posts: 95
Likes: 0
From: USA
LS7 Carb intake manifold pressure drop? 
Orange line is manifold pressure kPa, purple being RPM. Manifold pressure starts off at ~95kpa (97kPa was atmospheric) and @ 7500RPM is down to 84kPa. This is done without any filter (restrictions).
The 1/4" pressure tap is located in between the 7 & 8 runners on the vertical plane (wall connecting roof and floor).
Looks like there may be a venturi effect that is actually creating vacuum on the tap location? Thinking of moving this to the floor of the manifold, dead center.
Comments?
Crazy. Your results certainly could be backed by moving the measurement point. Restriction was on the tip of my tongue until you mentioned no filter... It's a little lean down there at the sample point too, fwiw, not that it has any bearing on this. 0.95L
Thread Starter
Staging Lane
Joined: Aug 2005
Posts: 95
Likes: 0
From: USA
I would have loved to gotten it down to .88-.90, but the interesting thing about that: I'm limited to 1% changes which swing lambda 4-5% in each direction with the breakpoints I have scaled. To keep the RPM range required, I really can't modify them. 
On the plus side, it did lay down 550whp (mustang) @ 7500
On the plus side, it did lay down 550whp (mustang) @ 7500
Yeah I understand, sometimes you have to give it up in some places to get it where you need it most. If you move the measurement point, post back up your results if you don't mind. Good luck with the setup, sounds sweet.
Thread Starter
Staging Lane
Joined: Aug 2005
Posts: 95
Likes: 0
From: USA
... I'll drink to that one 
