Injector Placement and Firing
06-15-2010, 07:31 AM
#1
Injector Placement and Firing It's my understanding that the higher you put the injector in the intake runner, the better the fuel atomizes (think carburetor) at higher rpms. You look at the Gen III cathedral port design, and it puts the injector spraying on the intake valve which is probably great for emissions, idle quality, fuel economy and low rpm performance, especially if you're firing the injectors sequentially. If we're talking about a super vic intake, how much power is there to be found by placing the injectors say... 3 or 4 inches higher in the intake runner and batch firing the injectors? Lets use my LT1 as the example motor, with a powerband of 5000-7500 rpm with a cam in the 270 @ .050 range. Injectors are 60#, stock LT1 fuel pressure running E85.
Also, can you still change individual cylinder injector coefficients in DFI while running batch fire?
Also, can you still change individual cylinder injector coefficients in DFI while running batch fire?
06-18-2010, 05:46 PM
#2
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I read a magazine a while back with a 800hp motor with a sheet metal intake and the higher they raised the injector the more hp they made. I believe it was worth 40 hp on a 800 hp engine. down size was idle quality. So they just raised the idle rpm.
Bob
Bob
06-19-2010, 03:04 AM
#4
ALOT of race cars here using sub 2.5ltr 4pot engines run a second set of injectors higher in the intake tract. the idea is you get better a better air to fuel mixture and thus more power. i have seen a BMW that mounted the second injectors some 12inches or more from the intake ports! how you would do this on a LS engine is deyond me!
iF1 guys, and other i have seen, also fire the fuel into the intake horn! it creates almost a mist just above the horn. lol works pretty well for them though.
moght be worth looking into running a pair of smaller injectors. these should give better fuel distribution and smaller fuel droplets anyway. plus im guessing would be much eaiser to package....
Chris.
iF1 guys, and other i have seen, also fire the fuel into the intake horn! it creates almost a mist just above the horn. lol works pretty well for them though.
moght be worth looking into running a pair of smaller injectors. these should give better fuel distribution and smaller fuel droplets anyway. plus im guessing would be much eaiser to package....
Chris.
06-19-2010, 09:23 AM
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06-19-2010, 02:51 PM
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Much of the gain would be from the latent heat of vaporization of the fuel in the intake. As the fuel atomizes (evaporates) in the intake stream, it cools the air/fuel charge. This is one of the reasons why a wet flow system will make more absoloute power than a dry flow manifold.
Shane
Shane
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06-19-2010, 07:37 PM
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Much of the gain would be from the latent heat of vaporization of the fuel in the intake. As the fuel atomizes (evaporates) in the intake stream, it cools the air/fuel charge. This is one of the reasons why a wet flow system will make more absoloute power than a dry flow manifold.
Shane
Shane
