angcobra

I searched through the earlier posts, found 1 very intersting one https://mustangforums.com/m_252511/m...njector/tm.htm
What I saw was you know how to determine injector size.
I am building and engine, so I don't know HP yet.

347 stroker
Trick Flow twisted wedge heads (ported)
Performer clone intake (gasket match porting)
75 MM MAF
70 MM TB
3rd stage Trick Flow cam (largest for hydraulic rollers)
Paxton NOVi 1000 (6psi boost)

primetime5.0

i would say 42# ers?

StangTangGT

no way that big! i bet you could use a 190 lph fuel pump, 24 lb injectors and a fuel pressure regulator. if your picking a six pound supercharger obviously your setting your hp limit/potential. id say even if you get 400 horsepower the larger fuel pump would provide plenty of fuel. or you could probably do stock fuel pump and 30 lb injectors and a regulator. but i wouldnt recommend it. 42 lb injectors are rated at like 600+ hp you dont need that much. a 6lb blower ona stock car needs no alteration of fuel system. but since its a 347 you might need some modification but not a huge alteration. sounds like a good setup though.

mdvaldosta

injectors are rated differently depending on whether your NA or boosted, since with boosted motors you run more fuel. 42's are good to about 550 flywheel hp (theoretically) on a boosted car @ 39psi. You can probably squeeze 600 flywheel hp outta them with jacked up fuel pressure. I think you will need at least 42's to be safe, I wouldn't be suprised to see you get 550 hp outta that motor at the flywheel. I make about 490 to the flywheel with my little 281 @ 9 psi. I also run 42# injectors, their alittle big but will give me room to grow. No drivability issues either.

angcobra

Thanks, my goal is to get 450 RWHP to match my 03 Cobra. From all I have read that HP should be safe for the components I am putting in it and not break the block. I currently have a 185 lph fuel pump with pressure regulator and 24# injectors. The car was running this way as a 302 with 6# of boost. I am concerned the larger displacement and camshaft will be too much for the 24# injectors.
Shoulld I put together what I have and let the dyno tell me what size injectors to go with or just go ahead with the 42# (which will also cause me to buy some other stuff like new MAF meter)?

Also here is pic of my new project

[IMG]local://upfiles/10436/49B93AC1EEF44B1D81A90AB62ADACAE9.jpg[/IMG]

mdvaldosta

24's won't under any circumstance support 450rwhp of blown power. might could push 30's or 36's but since you've gotta upgrade anyways might as well get 42's

angcobra

Thanks, guess I better get on ebay. Anything other than the MAF meter that must also change? Could I use injectors and meter from Cobra or Lightning?

StangTangGT

but doesnt 6 psi of boost only put out about 25-30% more horsepower? plus hes not really growing at all. hed have to buy a whole new head unit to put out any more boost. i have two pumps and 30 lb injectors in my setup and am running really rich. but hey if md says it works fine in his then go for it.

Predator

All I can say is see if you can get your MAF tuned for your injector size and all that good stuff. But if you have the MAF already, I guess you can't; however I think you can get a few more HP out of matching injector size to MAF tunage.

vfast

L@ stang...md is NO car god and the reason your running rich is the car IS NOT TUNE correctly.......42's WITH NO CHIP YOUR ASKING FOR IDLE PROBLEMS UNLESS WITH THEM YOUR RUNNING LEAN...WHICH I DOUBT with 5 psi 24's can be use with a SFMU with great results when the A/F RATIO is tuned out