FMU or Injectors?

[silverstang93]

hey everyone
i just bought my 1000 kit in December and had it put on but i am about to up the boost. I have bought an 8" crank pulley and I am looking for a power pipe so i'm expecting around 8 to 10 pounds of boost. Right now I have 24lb injectors and a 255lph fuel pump but I am not running an FMU. I know I am pushing my luck now w/o using an FMU but I know I will either have to get an FMU or larger injectors after i increase the boost. My other mods include: Performer Intake, eql headers, off road H-Pipe, 70mm TB, and a 75mm Pro M Mass air meter. What would be my best route injectors or FMU. If injectors what size, if FMU what kind. I have an FMU that came with my kit but i think it is calibrated for 19lb injectors and i have changed mine to 24lb so i was running very rich so i took it off. Should i use this FMU. thanks for your help.

[Doug]

With your mods I would suggest 36 pound injectors. It may seem a little big, but if you are going to do heads in the future they will work fine.

[silverstang93]

Do you think that will be enough w/o an FMU and what fuel pressure do you think i should run w/ 36.

[Doug]

I've personally made over 475 rwhp with 36's and no FMU. Set the fuel pressure to stock to start with. If you know how to read a spark, then get on it, listen for detonation, and then pull a plug to rea it. If you don't know how, get it dyno-tuned.
Doug

[mheinjr]

I had the same combo you had, except I had a GT-40 intake, and I usec 36lb injectors and no FMU, and Everything worked out fine....

[silverstang93]

thanks for your help i guess i am going to get the 36s then. I just put the 24s and a new Pro M in this past summer. I wish i new then what i know now but at the time i was not planning on buying a blower. Well if any one know someone who wants some 24lb w/ about 2000 miles on them i will be selling mine in about a month.

[ray95]

I would get 42# injectors now. Eventually you will buy heads for the car and will make more power and will need to upgrade the 36's. Get the 42's now, recalibrate the MAF, and get a good tune. You won't have to worry about injectors for a while.

[mheinjr]

I saw a injector chart and believe it or not 36lb injectors could hold up to some good hp. I think 36's are fine if you are only going to like 550! I mean if your doing some serious racing, and stuff than go to 42's, but do what you want... Maybe you should get 42's why not... They might actually be cheaper! I know I paid a sh*t load for my 36's

[silverstang93]

thanks for the info mheinjr i think i will go w/ the 42s and a tune b/c i want to do a 347 motor in the next couple years.

[slow91]

hey silver, I blew a h/g with your set up. i'm upgrading to 42's and loosing the fmu. also picked up some tw heads. definitely getting a good dyno tune this time.

[silverstang93]

slow91 do you think you blew the h/g because of the injector size or b/c you had a cam and 8" pulley?

[slow91]

well I was really pushing the limits of the 24's using the 8" pulley and the other mods. I was hitting 9lbs of boost. car also had no tune or custom chip.

[silverstang93]

yea i would say you went over the limit of those 24s. lol. I have the 8" crank but its not on the car so since i am not running an FMU I am going to wait until i get some more injectors to put it on. I am going to put 42lb injectors, power pipe, 8" pulley, and 1.6 r/r all on at the same time and have it tuned w/ a custom chip. how much power do you think all of that will give me?

[slow91]

I would guess about 350 or so. maybe more with a good tune.

[regattacoupe]

The 8" crank owns! MY car was 100% meaner when i did the swap. 6mph speaks for the HP and the torque down low was a huge improvement. My car was really rich with stock pullies and the C&L i was running so i thought, Hmmm, Add boost or cut fuel?

No Brainer! just don't skimp on the fuel!