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Discussion Starter #1
Has anyone been playing with this? We want to introduce some fuel as far away from the intake valve as possible to aid in atomization and charge cooling. We also want fuel directly in the port to achieve cyl to cyl balance/correction. Billet Atomizer wide angle spray pattern vs narrow pattern we see on other injectors. Anyone done any testing in these areas and seen anything?
 

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Discussion Starter #2
Injector sizing, do we want the "port" injector to be as close to 100% DC as possible, or do we want it sized to be open while the intake valve is off the seat, or close to that duration to eliminate fuel puddling on the back of the valve?
 

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the old Kinsler efi set up on their Crower (Look-a-like) staggered stack intakes had the injectors above the butterflies.....worked terrible down low......pretty much a full open situation to make them run well....
 

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ls1 s/s notch on 28s
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wasnt there a thread on this or maybe it was talked about in the prostock thread..from what ive gathered is you want them high as can be in the intake an to also have a shit ton of pressure on the injectors but not a crazy duty cycle..if you look at f1 cars you can see how some do lile abobe an the injectors are before the throttle blades
 

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Lots... it means nothing in the traditional sense of placing it in the runner. Not Angle, not position, nothing. Folks can come up with a lot of ways they believe there's right and wrong positions and give all sorts of reasons and experiences.... but, it means nothing where you put it in the runner. Just my experience and opinion.
 

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EFI/N2O JUNKIE
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As far as duty cycle goes, if you want to be able to play with injector timing, you need to go really large compared to what you would normally run. Some claim power to be found, we know in street cars you can make them run a lot cleaner. If you are close to 80% duty cycle, you can't change when the injector opens too much (in relation to the intake valve opening). If the injector is only running at 50%, or less, then you can move the injector event timing around a lot.
 

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Exactly.Why over think it.Every scenario has been tried.if there was something that worked we would all of heard by now.Look what it cost gm to do new vette engine with nozzle in comb chamber with high pressure.Basically nill for results over past stuff.
 

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you want the fuel delivery to mimic the carb and more, spray only when air is moving in the correct direction (means small duty is needed like 30%) and introduced as far upstream as possible for best WOT power. to help drivability you want to spray at the back of an open valve with an injector close to the valve which means you need a staged injection setup to have the best outcome across the board.
 

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ls1 s/s notch on 28s
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yeah gm sets up their engines to spray just before the intake valve is fully open..they use thw hot intake valve to help air rate the fuel better..in hp tuners this is called eoit an then you have the boundary..ive heard that playing with it can gain power down low but it can cost you up top..there is some calculators you can use to figure out what to try..im still trying to learn about it..im sure holley or most other systems have somwthing like this,that allows you to time the spray of the injector
 

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Discussion Starter #13
Interesting replies. Will post some pics of what we are trying once I get the intake finished up. Will be injecting 50% of fuel into the smallest cross section of the plenum (8 inches from 1st runner entry, 20 inches from rear runner entry) rest of fuel will be in ports. Will be interesting to see how the cyl to cyl correction will be.
 

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Discussion Starter #15
Heres what we came up with. 4 injectors at the inlet, 2 showering the plenum, 1 per hole. Seems promising so far, see what the hub dyno says in a few weeks.
63205

63206
 

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Q(t)=ṁCpΔT
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If you search around a bit, The F1 guys put the injectors inside the plenum above the runners. They also have a smalll bell entry at the end of the runner.

I would like to see this to see if there is anything to be gained.
 

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No reply from Shawn???
 
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