Where To Place Fuel Injectors?
01-08-2005, 09:49 AM
#21
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Originally Posted by renns' date='Jan 7 2005, 11:56 AM
These statements match with my experience as well. I mounted 4 injectors up high in the runners (see below), and tried to use them in place of the stock injector locations. I could not get decent idle/low rpm operation with the primaries in that location. I suspect at idle the low airflow, large runner area, and injector firing against the opposite wall ended up resulting in the fuel wetting out the manifold.
Roger.
Roger.
Nice, too bad it didn't work for you. What injector bungs did you use?
CW
01-08-2005, 03:42 PM
#22
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I think that any well designed system should involve mounting the injectors in BOTH locations . In the primary location you could mount relatively small sized injectors, so that the "bad atomization" and "drop out" phenomena are minimized and the low RPM , off boost operation is just as good as stock .
The secondaries should be placed further away from the intake ports (witjin reason of course) and can be of a larger size , since the extra distance and resulting longer time for the fuel to reach the intake ports allows for a good degree of fuel atomization.
I have since switched to a Pro Jay intake set up , I am using a pair of 550's as primaries in the stock location and 4x1600's up at the throttle body .
The secondaries should be placed further away from the intake ports (witjin reason of course) and can be of a larger size , since the extra distance and resulting longer time for the fuel to reach the intake ports allows for a good degree of fuel atomization.
I have since switched to a Pro Jay intake set up , I am using a pair of 550's as primaries in the stock location and 4x1600's up at the throttle body .
01-08-2005, 04:35 PM
#23
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Originally Posted by DuMaurier 7' date='Jan 8 2005, 02:41 PM
I think that any well designed system should involve mounting the injectors in BOTH locations . In the primary location you could mount relatively small sized injectors, so that the "bad atomization" and "drop out" phenomena are minimized and the low RPM , off boost operation is just as good as stock .
The secondaries should be placed further away from the intake ports (witjin reason of course) and can be of a larger size , since the extra distance and resulting longer time for the fuel to reach the intake ports allows for a good degree of fuel atomization.
I have since switched to a Pro Jay intake set up , I am using a pair of 550's as primaries in the stock location and 4x1600's up at the throttle body .
The secondaries should be placed further away from the intake ports (witjin reason of course) and can be of a larger size , since the extra distance and resulting longer time for the fuel to reach the intake ports allows for a good degree of fuel atomization.
I have since switched to a Pro Jay intake set up , I am using a pair of 550's as primaries in the stock location and 4x1600's up at the throttle body .
Does the pro jay set-up allow for staged throttle?
01-08-2005, 07:53 PM
#24
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Originally Posted by z8cw' date='Jan 8 2005, 07:49 AM
I measured the stock injector mounting interface, made a drawing, and had a machinist friend whip them up on the lathe. I then cut and fit them to the stock manifold.
Roger.
01-09-2005, 07:43 PM
#25
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Originally Posted by z8cw' date='Jan 8 2005, 02:35 PM
No it doesnt , but there are other TB's that feature staged butterflies. I chose the Prolay case of it high flow capacity (1250+cfm) and price .
01-09-2005, 07:59 PM
#26
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Originally Posted by renns' date='Jan 7 2005, 01:56 PM
These statements match with my experience as well. I mounted 4 injectors up high in the runners (see below), and tried to use them in place of the stock injector locations. I could not get decent idle/low rpm operation with the primaries in that location. I suspect at idle the low airflow, large runner area, and injector firing against the opposite wall ended up resulting in the fuel wetting out the manifold.
Roger.
Roger.
why don't you just run 6 550's?? use the same primary setup to help the idle, then stage the other 4
01-09-2005, 09:24 PM
#27
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Originally Posted by mazdadrifter' date='Jan 9 2005, 05:59 PM
why don't you just run 6 550's?? use the same primary setup to help the idle, then stage the other 4
Roger.
01-09-2005, 10:31 PM
#28
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Originally Posted by DuMaurier 7' date='Jan 9 2005, 06:43 PM
No it doesnt , but there are other TB's that feature staged butterflies. I chose the Prolay case of it high flow capacity (1250+cfm) and price .
Wooh, that is more than twicw of what our engines can flow at 10k rpm, I believe. Did you get the semi pp LIM or did you decide not to go that route.
CW
01-10-2005, 06:49 AM
#30
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Originally Posted by Jono19' date='Dec 29 2004, 07:23 AM
The tuner im using ( it was on a Rolling Road at the time) 
is suggesting that the injectors may be to close to the chambers and as they are injecting towards the front this 'may' be running the fuel lean to the back.
Sounds possible'ish or does it??? before i spend on an alternative what do you think??
J.
Sounds possible'ish or does it??? before i spend on an alternative what do you think??
J.
You need a different tuner that knows what he's doing.