01yellerCobra
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The 60's should definitly give you some room. I know of a couple guys running them in to the 600's with Whipples and Kenne Bells. I'm running 80lb injectors in my Cobra. I wanted to never need to upgrade again.
Vortech install on 04 EB 5.4L
- Thread starter joezek
- Start date
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With me giving advise on properly sizing fuel injectors and pump for hp level I decided to go back and check mine since I added boost from original build. Turns out I am at or near 100% duty cycle at my peak hp using the fuel calulators.Not good. May have been the underlying issue at my last track outing.
Figuring 15-20% drivetrain loss puts me between 566-600 flywheel horsepower. Considering it is a large 4wd the drivetrain losses may be greater. (More rotating mass) This puts me right at 100% duty cycle with .55 bsfc for superchargers. Your shooting for 80% duty cycle max. 52# injectors is what it recommends in my case.... as long as I dont mod it any more or have better air than the day it was dyno'd
Think I will get some 60# injectors and be done with it. It will be interesting to see if it effects my top end.
What kind of fuel pressure regulator are you running? Can you bump up the pressure to increase the injector flow rate so that it imitates 52# injectors (like the FMU does)?
In my case, I have stock cams, intake, and heads. I don't have headers either, and I'm running stock rpm range. I won't have anywhere near the CFM flow that you do, I'm sure the 39LB/42LB injectors are plenty for mine. I'd like to get a little build going in my spare time and do it right, with the right heads/cams and a KB or Wipple style blower. Just need to find an engine somewhere to tear down and start modding.
Aeromotive I believe at about 45 psi @ zero vacuum & boost. Dont think it would be a bad idea if it was small increase. But I checked and I would have to increase my fuel pressure to 67 lbs base and with 14#'s of boost that puts it at 81. Not comfortable running that kind of pressure. Set up as an fmu where the increase is only seen under boost may be ok but its easier to change injectors. The increased pressure also loads the fuel pump more and decreases its overall volume capacity. Some fuel injectors may have issues with the higher pressures as well.
With your target HP level you should be fine. The problem would be when and if you decide to make more power. Then you really need to be concerned with your stock rods!!
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I was going by the rule I heard among the lightning community that stock injectors were good for around 500 rwhp. Just didnt realize how dangerously close this puts you to maxing them out. 60's seem to be the very popular with lightning crowd with the exception of those making crazy hp levels.
1997SCEBFEX
Full Access Members
Just found this thread:
Plenty of pics in the Blown EXPY section/albums.
V2-SQ w/ oil return to S/C off oil filter housing behind driver's grill
Aftercooler w/ B&M additional cooler located behind the grill and temp sensor; upgraded marine aerator pump (1100 gpm)
Granatelli MAF w/ K&N
T-rex fuel pump
After the rebuild due to #3 passenger plug being ejected/ingested cracking the head, both heads were polished/ported flowing more air as part of the machining.
Link to pics: http://www.expeditionforum.com/members/43969-albums199.html
Plenty of pics in the Blown EXPY section/albums.
V2-SQ w/ oil return to S/C off oil filter housing behind driver's grill
Aftercooler w/ B&M additional cooler located behind the grill and temp sensor; upgraded marine aerator pump (1100 gpm)
Granatelli MAF w/ K&N
T-rex fuel pump
After the rebuild due to #3 passenger plug being ejected/ingested cracking the head, both heads were polished/ported flowing more air as part of the machining.
Link to pics: http://www.expeditionforum.com/members/43969-albums199.html
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