how much hp are my Injectors good for?
#1
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I got into an argument with a friend the other day, and he told me that the injectors im putting in my car for my supercharger are too small, im installing a magnacharger on an 02 ls1, should be 8-10 psi. I went with 60# injectors. and I was also wondering what the stock injectors can support for N/A power.
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This one has a cool tool to calculate the horsepower capacity of injectors based on their flow rating:
http://injector.com/injectorselection.php
http://injector.com/injectorselection.php
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He has only 4 cylinders making 300 hp, now make 300hp with 8 cylinders, on the 8 cylinder each cylinder does not have to make as much power as a 4 cylinder.
Example, 4 cylinder engine, each cylinder makes 75 hp to get 300 hp total
8 cylinder engine, each cylinder makes 37.5 hp to get 300 hp total.
(assuming both engines redline at same rpm)
Example, 4 cylinder engine, each cylinder makes 75 hp to get 300 hp total
8 cylinder engine, each cylinder makes 37.5 hp to get 300 hp total.
(assuming both engines redline at same rpm)
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I guess what my question is, does your car have any issues running the stock injectors?
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with that much HP the stockers will be too small. I'm running in the 430rwhp range and put in 42lb. The tuner has the ability to adjust them even further. I know you don't want to exceed like 80% of the duty cycle for injectors.
Don't put bigger injectors in until you get to the shop that is going to tune your car or you could have big issues.
Don't put bigger injectors in until you get to the shop that is going to tune your car or you could have big issues.
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you would not have gotten away with 42# injectors. You would have needed at least 50# or so to meet the 85% duty cycle maximum.
750cc injectors are 71.36# injectors
my injectors are Injector Dynamics 725cc @ 43.5psi. I'm running them at 58psi, SO, 79.6# injectors at that pressure.
I'm making 650RWHP and 667RWTQ at 13psi at approx AFR of 11.4, this is with a 70% duty cycle. I'm turbo.
Those 60# injectors are 631cc rated. For your supercharged setup you will be fine as your BSFC is lower than my turbo setup. RCENG website. Technical Sizing.
Link to this at Fuel and injector sticky
Ask your buddy what his duty cycle is and what AFR he is running.
The above statement about cylinders & fueling & power is correct.
4 cylinders making 500HP takes a hell of a lot more fuel than 8 cylinders trying to make 500HP.
I do not know what motor you are putting this on nor what is done to it, but if it doesn't have forged internals & studded heads, I would recommend keeping the boost under 10psi, preferably at 8psi MAX
Last edited by ZL1Killa; 06-21-2011 at 05:26 PM.