Ive allready bought a new throttle body, manifold and adjustable fuel regulator. Ive been talking to some friends, unfortunitly chevy friends and they dont know squat about injection if its not tpi. Are trucks come with 19lbs injectors and they handle up to around 300 hp, I think. I am not, as of the next month before I go off to school, buying new heads unless I find some amazing deal for edelbrock performrer 5.0 heads. I have been surfing the mustang boards and many of them have 24lbs injectors with just aftermarket tb, intake manifold and regulators. I know im no stallion but we are pretty close. Has anyone changed injectors and have experience with this? Even if you have only heard stuff I like to hear. This is just some prelim research before I coff up the cash!

 

I dont know about the injectors but are you dead set on the edelbrock heads. You could get some ford gt-40 cast iron heads from some stang people for cheap

 

A normally aspirated 5.0 has a BSFC (brake specific fuel consumption) of about 0.50 lb/hp hr

So for 8 injectors you're good to about:

((19#/hr x 8)/0.50) x 0.90 (90% duty cycle) = 274 HP

24# injectors are good to about 345 HP. Some engines have better BSFC numbers, approaching .45 which allows them to make more power from a given amount of fuel, but .5 is a good safe "ballpark" for planning purposes. Use 0.55 for supercharged engines.

Bigger injectors will not add more HP unless the existing injectors are running at or near max, they will simply allow you to make modifications that will make more power. They may give better throttle response than the stock units.

An adjustable regulator allows you to vary the max thruput of your injectors. The flow thru an injector is proportional to the square root of the pressure drop, so increasing the pressure on your 19# units from 39 PSI to 45 PSI changes their thruput to only:

(45/39)^0.5 x 19 = 20.4 Lb/hr.

It takes pretty big pressure changes to get much change in flow rate.

Even with aftermarket heads, you're not likely to get past the HP capability of your stock injectors unless you add a fairly stout camshaft. Remember when you change injectors, you need to either change or recalibrate your mass-air meter.

FWIW on a truck, aluminum heads are probably a waste of money. It's not going to be a lightweight no matter what you do. Ford GT40 iron heads are readily available at swap meets from all the Mustang guys who swapped them for aluminum.

 

...now how in the hell does someone come up with equations like that. All I see is
(($%#/hr x ^)/0.*0) x 0.!@ (*0% duty cycle) = 274 HP
or spoken
yadda yadda yadda/yadda yadda(yadda x yadda) =274 HP

boggles the mind

 

Ford4Fun,
you just said you have a 274HP toilet.

LOL

 

big equation but where do you figure out things like that is there some book im missing???????? LOL