Injector size.
08-06-2001, 09:21 PM
#1
Safety Car
Thread Starter
Injector size.
Ok...tell me what you think:
I have a Holley Projection setup, good for 600 HP. I used to use it on my '79 383. I'm extrapolating...my build of my 350 will make around 425-440 HP. Thats about 80% of the power the Projection is rated for. The Projection has four 80 pound injectors. So, for equivalant...that comes out to eight 40 pound injectors on a TPI setup.
So, lets say I make 80% of that power...that means I would need 32 pound injectors. I wonder if 30 pound injectors with a little bost in pressure will work?
Another thing...the Projection runs a variable pattern injector sequence. At idle, it runs one of the 4 injectors at a time, in sequence, so as to not dump more fuel than would be needed for low speed tuneability. At 3000 RPM or so, it switches to simultaneously firing two injectors in alternating banks..for increase flow. At max throttle high speed, it banks all four injectors together...so there is 3 stages of fuel flow.
If I think about hte flow stages, wouldn't it mean at idle, a single 30 pound injector might be too much for a single cylinder? :confused:
I have a Holley Projection setup, good for 600 HP. I used to use it on my '79 383. I'm extrapolating...my build of my 350 will make around 425-440 HP. Thats about 80% of the power the Projection is rated for. The Projection has four 80 pound injectors. So, for equivalant...that comes out to eight 40 pound injectors on a TPI setup.
So, lets say I make 80% of that power...that means I would need 32 pound injectors. I wonder if 30 pound injectors with a little bost in pressure will work?
Another thing...the Projection runs a variable pattern injector sequence. At idle, it runs one of the 4 injectors at a time, in sequence, so as to not dump more fuel than would be needed for low speed tuneability. At 3000 RPM or so, it switches to simultaneously firing two injectors in alternating banks..for increase flow. At max throttle high speed, it banks all four injectors together...so there is 3 stages of fuel flow.
If I think about hte flow stages, wouldn't it mean at idle, a single 30 pound injector might be too much for a single cylinder? :confused:
08-07-2001, 04:38 AM
#2
Burning Brakes
Member Since: Sep 2000
Location: NewCastle IN. USA
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Re: Injector size. (BBA)
injector sizing is a very debated topic.
A rookie's view:
I think that it depends on a lot of things, batch fire or sequenceical (spelling),
what RPM you plan to make the power at, engine size, ect ect.
the higher the RPM the less time available for the injector to supply the fuel, hence bigger injectors are needed to supply the extra fuel in a shorter time.
the system has to be reprogramed for less fuel at low RPM's.
that's probably why the holley system cuts back the number of injectors used at low RPM's.
lots of people here seem to have made different injectors work.
I think it is a matter of keeping the fuel pressure at or near the recommended setting so the spray pattern is good, then cutting back the length of time the injector fires at low RPM's.
"my not too experienced opinion".
A rookie's view:
I think that it depends on a lot of things, batch fire or sequenceical (spelling),
what RPM you plan to make the power at, engine size, ect ect.
the higher the RPM the less time available for the injector to supply the fuel, hence bigger injectors are needed to supply the extra fuel in a shorter time.
the system has to be reprogramed for less fuel at low RPM's.
that's probably why the holley system cuts back the number of injectors used at low RPM's.
lots of people here seem to have made different injectors work.
I think it is a matter of keeping the fuel pressure at or near the recommended setting so the spray pattern is good, then cutting back the length of time the injector fires at low RPM's.
"my not too experienced opinion".