lou427f Posted September 21, 2006 Report Share Posted September 21, 2006 I havnt seen more that 7 psi or so, no where near 9! I assume the computer is limiting it. Temp here has been in 80's, 4500 ft alt and low humidity. SAE net HP ratings assume 77 degrees, sea level alt and no humidity...is that what it takes to get 9 psi?? How is it controlled, a waste gate/by-pass? Excuse the dumb questions...I'm used to holly carbs!! Link to comment Share on other sites More sharing options...
carnut Posted September 21, 2006 Report Share Posted September 21, 2006 I havnt seen more that 7 psi or so, no where near 9! I assume the computer is limiting it. Temp here has been in 80's, 4500 ft alt and low humidity. SAE net HP ratings assume 77 degrees, sea level alt and no humidity...is that what it takes to get 9 psi?? How is it controlled, a waste gate/by-pass? Excuse the dumb questions...I'm used to holly carbs!! The supercharger uses a by-pass valve. I am getting about 9 down in Phoenix which is about 1200 feet altitude. I have about 600 mile on the car. It seems that the 9 is at higher rpm with the engine warmed up.Dumb question, is the engine fully warmed and have you checked above 5000 rpm? Link to comment Share on other sites More sharing options...
BoneDoc Posted September 21, 2006 Report Share Posted September 21, 2006 i see 9 boost routinely..... i drive in denver (5280 elevation, very little humidity, temp averag about 70 this time of year) kicks in with even the tamest of takeoffs..... Link to comment Share on other sites More sharing options...
lou427f Posted September 21, 2006 Author Report Share Posted September 21, 2006 The supercharger uses a by-pass valve. I am getting about 9 down in Phoenix which is about 1200 feet altitude. I have about 600 mile on the car. It seems that the 9 is at higher rpm with the engine warmed up.Dumb question, is the engine fully warmed and have you checked above 5000 rpm? Yes and yes!! I have about 900 miles... Link to comment Share on other sites More sharing options...
TAHOE GT Posted September 21, 2006 Report Share Posted September 21, 2006 Here is my dyno sheet that lists the boost pressure in inches of mercury. The column on the right labeled "Man.P". If you look at the numbers devide by 2 to get psi. (It's really like 2.02xx) My understanding is that boost is limited to 8.75psi. The dyno sheet shows that. If you look at 4500-5500rpm boost drops a bit. This is because the engine is operating at Max Volumetric Efficiency. So, the engine is breathing the very most air it can which lowers manifold pressure a bit. Link to comment Share on other sites More sharing options...
lou427f Posted September 22, 2006 Author Report Share Posted September 22, 2006 Here is my dyno sheet that lists the boost pressure in inches of mercury. The column on the right labeled "Man.P". If you look at the numbers devide by 2 to get psi. (It's really like 2.02xx) My understanding is that boost is limited to 8.75psi. The dyno sheet shows that. If you look at 4500-5500rpm boost drops a bit. This is because the engine is operating at Max Volumetric Efficiency. So, the engine is breathing the very most air it can which lowers manifold pressure a bit. Great info, thanks!! Good et...speed seems low for et tho?! Link to comment Share on other sites More sharing options...
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