Injector help please

[Mike in Texas]

My 1990 7up model has a gt40 crate engine w/ aluminum heads, e303 cam, cobra intakes, 65 mm throttle body, 76mm C&L maf, 255 fuel pump, adj regulator, and ceramic coated shorty headers. Do I need to move up to 24# inj or can I stay stock?

 

[DMAN302]

I would say if the car is running well you could well move up to a larger maf and keep the 19's..or if future upgrades like a head upgrade I would look to jump to the larger injectors and maf.

 

[legalize420]

i was running rich with 24's. do the aluminum gt40's flow the same as the cast? i would put the money elsewhere. do you have gears yet?

 

[jrichker]

If the advertised HP on the crate engine was over 300, you would get best results with 24 lb injectors.

 

[88_GT_5_oh]

i have some used 24's for sale..... i just wanna get rid of the damn things.

 

[04sleeper]

Your car should be fine running stock 19's.

 

[hessian]

it can run fine with 19# but i would go ahead and put 24# in. if you went with a larger throttle body i would say go 30#. but always remember that you will be able to adjust the pressure of your fuel and when you need the bigger injectors and dont have them you'll be singing a different tune.

 

[5spd GT]

30lbers are definately not needed. I have them and they are to big for a bit more aggressive setup. I wish I would have went with 24's.

24's would be a more ideal setup if you can swing the price and maf calibration. 19's will work though.

hessian - A throttle body isn't going to do anything significant enough at all to warrant an injector change of 6lbs. That is roughly a 20% injector lb per hour change just buy adding a couple hp. Not needed for sure

 

[1SLO306]

this is goin on in a different thread too. http://forums.stangnet.com/showthread.php?t=600322

 

[BaXTeR3221]

24's, so you have room to upgrade. 30's prolly wont be needed unless you stroke it(which i assume you wont since you just bought a new shortblock) or if you add boost, in which case you'll need even more fuel.

 

[Mike in Texas]

Thank you for the advice. Yes, 3.55 gearing. I'm not sure if the aluminum heads have differnt flow than the iron. Good question.

 

[BaXTeR3221]

I'm almost positive aluminum's flow better than the irons, but i could be wrong.

 

[Mike in Texas]

Thank you all for the advice. Any recommendations on the best fuel pressure if I keep the 19# injectors?

 

[5spd GT]

You will probably want to be in the mid 40psi range with vac. line disconnected.

 

[gcwh02]

i agree with 5spd, if you have the money maybe a tune and dyno would be a good idea with all those new mods

 

[mrbizkitt]

Maybe this will help you! http://www.injector.com/
Look under injector selection guide. If you know the hp of your motor, this can help make your decision.

 

[Mike in Texas]

Trying Out New Pic

Hope nobody minds that I sent this to my own message to check my profile pic.