Hi guys.
I can get a set of new Accel 24lb universal injectors at a decent price. The car has a mild cam, heads cleaned up, air intake and headers. Will the 24lber's work ok?
Thanks,
Martin.

 

there is a formula to figure this out.... lemme see if i can find it...

 

Just give Rich a call @ cruzin performance. You can visit the website which I think is www.cruzinperformance.com Rich knows his stuff and you can get a set of accells for around 230 american,he'll be able to help you out.

 

its from an issue of Chevy High Performance....
HP=lb/hr flow rate x 8 injectors x 0.8
0.5 brake-specific fuel consumption

....Using this formula you can estimate the amount of HP an injector can support. The 0.8 is a duty cycle rating of 80%, while the 0.5 Brake-Specific Fuel Consumption (BSFC) number is an efficiency rating of how well an engine transforms the fuel into power. The number refers to pounds of fuel per HP per hour or lb/hp/hr. Race engines can produce numbers in the low 0.4's. A smaller number is better because this means the engine requires less fuel to make power. Example w/ 36 pound.....
HP=36 x 8 x 0.8 HP=460
0.5
In this cas a 36 pound injector can support 460 horsepower with a line pressure of 43.5 PSI, This is a linear formula so a 72 pound would support 920hp, and an 18 pound would support 230hp. There are ways to cheat the system a little, for ex..bumping the duty cycle up to 85% on that 36pound injector and improving the BSFC to 0.45, pumps the horsepower potential to roughly 540, its a significant improvement, but it is best to stick with the basic formula. The other half of the equation is for when you have HP in mind and need to figure out what injector to use.....
Injector Flow Rate=Engine HP x BSFC
# of injectors x 0.8
ex. Injector flow rate = 500 x 0.5
(8 x 0.8)
Injector flow rate = 39 lb/hr


Hope this helps.....

 

to add:

raising the duty cycle will make the injector to "work harder" so put that into consideration..Also running the injector at high pressures can wear it prematurely..IMO I would go for the midpoint of the injectors pressure range and go for the minimum duty cycle possible..You dont want to go too low on the pressure because of spray "quality"..

Daz
87 IROC
Ford SVO 30# injectors...(34# on GMs rating)

 

I agree Daz, I was just writing from the article, and thought that might help him understand everything a little better

 

Supposedly the stock 22lb injectors for the 350 will support up to 300HP, so I'm sure the 24lb ones will be fine. They are not overkill so if you can get them at a good price then go for it.

 

trust me!! buy 22lbs... they will work great.. I have reseached this thing a hundred times.. for your car 16thowner 22lbs will be great... 24lbs are to big for you type of mods on your car...


but this is what i would do..
up to you..

 

Thanks for all the info guys.
I've been pricing injectors for awhile now, the cheapest aren't nessesarily the why to go, but the cheapest 22lber's I've found are $900 plus tax and they are Accel's.
These Accels are universal one's. They come in 18, 21 and 24lbs.
They cost $429can. plus tax. Wierd.
I guess I'm just trying figure out which will work better. The 21 or 24. It's less than 1/2 the cost, but possibly labour on top. I'd like to have them in for the 13th, but I'm not sure yet if I'll be able to install them myself.
After 2 dyno sessions, the engine is only putting out 182rwhp, but it wasn't running near peak either time. So, maybe 210-220 hp on those runs. The 21's should be enough. They are high impedience, with Busch type pintles.
Any suggestions or ideas are welcome.
Martin.

 

Thats great advice from stang eater and daz... If I were you I would wait till you get the plenum ported, bigger runners, and an aftermarket or ported base. Thats probably about the point where I will upgrade.

 

What is the stock injector rated at? What are good ones to get? 24?

 

The stock 350 injectors are 22lb.
It seems funny however, that a manufacturer (Accel) can produce 21 & 24lb injectors for less then 1/2 the cost of the 22's. Something rotten in Denmark...loll. I think they know they gotcha.
I've decided to order the 24lber's and if it doesn't work good cause there to big, I'll have to mod some more...hehe.
Martin.

 

The stock 350 injectors are 22lb.
It seems funny however, that a manufacturer (Accel) can produce 21 & 24lb injectors for less then 1/2 the cost of the 22's. Something rotten in Denmark...loll. I think they know they gotcha.
I've decided to order the 24lber's and if it doesn't work good cause there to big, I'll have to mod some more.
Martin.

 

Oops.

 

hey 16th owner..Drive your car to my house one morning and well do the injector swap in an hour..just bring gaskets and o-rings for the fuel line

Daz