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Post by Wayne Miller on Oct 2, 2012 21:32:36 GMT
I made a spread sheet last year to calculate a number of tuning formulas. To cut a long story short Ive lost it so Ive got to write all of the formulas again. Does anybody have any formulas that they can post up here?
Also if you feel that any of the formulas below are incorrect please send me a PM and I will look into an improved formula
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Post by Wayne Miller on Oct 2, 2012 21:34:17 GMT
I'll start with Calculating CC
=SUM(C5*C5*C4*0.7854)/1000
C5 = Bore
C4 = Stroke
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Post by Wayne Miller on Oct 3, 2012 0:30:37 GMT
Port Timing Calculator
=((180-DEGREES(ACOS((((C4/2)+C6+C8-C9)^2+(C4/2)^2-C6^2)/(2*(C4/2)*((C4/2)+C6+C8-C9)))))*2)
C4 = Stroke
C6 = Conrod
C8 = Deck Height*
C9 = Dist from top of cylinder to top of port
* When measuring Deck height. If you piston is 1mm lower than the top of your cylinder at TDC then you have a negative deck height of 1mm. If you piston is 1mm higher than the top of your cylinder at TDC then you have a positive deck height of 1mm
Do not be confused and enter -1 if you have a negative deck height. You need to enter 1 as this is the measurement from the top of the piston to the top of the cylinder. You should enter -1 if you have a positive deck height
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Post by Wayne Miller on Oct 3, 2012 1:02:17 GMT
Blowdown calculator
=SUM(((360-G10)/2)-((360-G9)/2))
G10 = Transfer Port Timing
G9 = Exhaust Port Timing
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Post by Wayne Miller on Oct 4, 2012 20:51:56 GMT
Calculate torque from BHP and RPM
=SUM(J5/J4)*5252
J5 = BHP
J4 = RPM
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Post by Wayne Miller on Oct 4, 2012 20:54:51 GMT
Calculate BMEP from RPM, BHP and CC
=(600000*(J5*0.746))/(G4*J4)
J5 = BHP
J4 = RPM
G4 = CC
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Post by Wayne Miller on Oct 4, 2012 21:15:41 GMT
Calculate engine power in Kw from BHP
=SUM(J5*0.746)
J5 = BHP
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