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03-25-2021, 08:21 AM | #1 |
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F.I. fuel pressure theories
36lb injectors at 50 psi or 42lb injectors at 40 psi . If I am able to achieve an optimal A/F either way...which will produce more power and greater consistency? Either? My theory is the higher pressure going through the smaller orifice will produce a finer mist..or better atomization which is always better? Or not?
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03-25-2021, 10:27 AM | #2 |
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Re: F.I. fuel pressure theories
Has anyone looked at say running the 42 lb injector at say 55 PSI which would have a reduced pulse width / duty cycle verses the 36 lb injector at 50 PSI?
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03-25-2021, 10:53 AM | #3 |
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Re: F.I. fuel pressure theories
I run my 24 lbs injectors at 70 psi. Theory is the injector acts larger and high pressure atomizes fuel better. I believe Ed Wright posted on this topic in the past.
Last edited by Pierce Jones; 03-25-2021 at 05:06 PM. |
03-25-2021, 11:44 AM | #4 |
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Re: F.I. fuel pressure theories
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03-25-2021, 12:11 PM | #5 |
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Re: F.I. fuel pressure theories
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03-25-2021, 12:48 PM | #6 | |
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Re: F.I. fuel pressure theories
Quote:
YMMV. |
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03-25-2021, 02:17 PM | #7 |
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Re: F.I. fuel pressure theories
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03-25-2021, 04:45 PM | #8 |
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Re: F.I. fuel pressure theories
I've been wondering this also. An oversized injector to get down to a low pulse width duty cycle? This is beneficial if you can phase the injector to spray at optimal time. Or a smaller injector with higher pressure for higher mist and atomization but it stays open longer and could be spraying at a closed valve.
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03-25-2021, 05:55 PM | #9 |
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Re: F.I. fuel pressure theories
Looking at a data log, my injectors (24 lbs/hr) are open 7.7msec (88% duty cycle) at 7000RPM (42 deg/msec). The intake has 308 deg dur @ .020”. So injectors are open 323 degrees of rotation and in my case spraying at a closed intake valve.
Not sure if any would be gained by a 36 lbs/hr etc. |
03-25-2021, 09:28 PM | #10 |
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Re: F.I. fuel pressure theories
I think so its a big stuff 3 i had it programmed for my car (99 Camaro) and had it installed First time at the track black smoke was rolling out at idle and was trying to load up. I haven't learned how to tune it yet so i turned fuel pressure down to about 42psi to clean it up. So my thought was to change to 36lb injectors so I could turn it back up....but if I can cure the problem by shortening the pulse width.....whats the difference?
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