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Old 03-25-2010, 03:32 PM   #7
KirkEvil
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Quote:
Originally Posted by Pampered-Z View Post
You are probably not getting a true 36 out of the injectors. You need more fuel which is why you are so far over the duty cycles. FP isn't really going to overcome that.

Below is the formulal I use for my car. This is from my Electromitive DFI, I shortened some of the text! Plugging in you numbers I come up 34 lb injectors.

From this your 30s are too small, you need 36s to stay in the 80% duty cycles.
That is basically the calculation I first went through when I was selecting injectors, and I came up with 32 lb/hr injectors using slightly different values. The 30 lb/hr SVO ford injectors are rated at 39.5 psi, and LS1 FP is 58 psi... so at 58 psi they should flow ~36.4 lb/hr, and accommodate both of our calculations.

If you back solve those equations with the 110% duty cycle, and 36 lb/hr for horsepower it comes to 598 bhp, which is definitely not what the engine is making.

Also, Im just trying to understand steps 3 & 4 of those equations...Is that supposed to calculate acceptable duty cycle based on max rpm? Ex. the duty cycle calculated with the steps increases with decreasing max rpm and vice versa. The calculations I did when selecting injectors always used 80% for IDC.
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