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Old April 7th, 2011, 08:55 PM   #1
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Join Date: Apr 2011
Location: Raleigh
Posts: 14
Default Dynamic Compression Ratio

Hi all, noob here. I'm trying to figure out how much boost I can run on pump gas. My static compression is 9.3:1. After doing some research my understanding is that dynamic compression has more of an impact on how much boost you can run. Here is where I am getting stuck. If I use this calculator if I input my static compression of 9.3:1 and boost of 6psi I get a "Boosted compression ratio" of 13:1

However if I use this calculator to determine my dynamic compression using the following input I get this outcome:
Cylinders: 8
Bore: 4.125
Stroke: 3.4
Rod Length: 5.315
Static compression: 9.3:1
Inlet Valve Closes ABDC: 74
Boost Pressure: 9
Target Altitude: 345

Static compression ratio of 9.3:1.
Effective stroke is 2.43 inches.
Your dynamic compression ratio is 6.86:1 .
Your dynamic cranking pressure is 129.99 PSI.
Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 9 PSI is 11.06 :1.
V/P (Volume to Pressure Index) is 101

My Cam:

Can somebody tell me what is the more important number here and what kind of boost I can really expect to run on this engine?
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