Silver88T

i have a 347 with 9psi of boostworked heads balanced upper lower intakes headers pipes 255 in tank pump and a 255 out of tank pump ..... my quetion deals with the fmu the powerdyne brand it says its for use with the 24 lb injectors but i got bigger ones and i heard u can run without the fmu if u have a strong enoough fuel system i dunno if thats true but i dont want to do the wrong thing what do i need to do to provide my car with the proper amount of fuel do i loose the fmu and if i do what else do i have to do so it runs im stuck!

uedlose

we ran without a FMU but we had 42# injectors and we had 13 psi showing.on the gauge after the Intercooler.What size Injectors do you have? The FMU sure is a nice band aid for a car that has small inj. in it but they can be tuff to tune always fat down low in the rs and start to lean out and run better up top.what ever you do keep the timming low and sneek up on the tune or you will be putting on head gaskets or worst hard parts.I have put on many of gaskets in the tuning of the wifes carnow if you have some kind of electronics to tune with like a PMS or a EPEC or a DFI and you could go in on the computer that would help you alot.the thing with the FMU is you can run a small injector and the fmu makes it think it is bigger by jacking up the fuel press.but big injectors can make idle problems come up. this is one of the better things about a fmu.dont know if this helped or hurt but if you have any ???? let me know.

FoxGT

Will work depending on what size injectors you have.

Silver88T

i have 48lb injectors

uedlose

you sould be fine with out a FMU with 48s but you still need to be careful. maybe you could get a egt gauge to keep a eye on your exhaust gas temperature.that would help you get a tune on the car.and would let you know if you are getting it lean.but getting the car tuned on a dyno would be the most help.I would start with 40 psi of fuel press and 9 degrees of timming.and go from there we run 36 degrees of timming down low and at 6200 RPM we are at around 22 degrees I pull it out as the rpm goes up we run a EPEC.but the car has a intercooler and only 8.0 to 1 compress.it sounds like you got the pumps.do you have good rails.the stock rails and lines are gone to be the next things that come into play if you go much farther.

FoxGT

^ [sm=exactly.gif][sm=goodidea.gif]

Silver88T

yes i got the rails and lines and ill prolly get it dynoed as soon as its together b4 i start it up thanks for ur help

FoxGT

Good luck with the car, got any pictures of it?