With a car making a little over 400hp and a 150 shot of N2O on top of that are 24# injectors too small? Even with higher fuel pressure?

 

At standard fuel pressure: inj size >= (HP / 12.8).
That is 80 % duty cycle, 8 cylinder.
J

 

What is standard pressure?... Ford's 37 something PSI or GM 44 somthing PSI?

 

Sorry, I don't follow the math. You mind explaining a bit more how it works? Let's say that NOS's advertised hp shot really give you 150hp. So then the equation is 24 >= (550/12.8). How do you get 80%?

 

Ford = 39.6 psi (2.7 bar), GM = 44.1 psi (3.0 bar)
J

 

wet or dry nitrous system??? wet, injectors don't matter.

 

Actually, your right. I forgot that the fuel in the wet system is added PRE-injectors. Yes it is a wet system. So you guys think 24# injectors will be fine? And please explain the equation to me, it seems pretty useful.

 

go to accel's web page. Plus how do you know you will be making 400 HP? Plus it depends on how efficient your engine is.

 

It doesn't matter the question is theoretical. I just need to know how much power 24# injectors can support.

 

Yes it matters. Having a .76 BSFC has way different fuel requirements than one with a .85. So, do like I told you earlier and read on accel's site and then ask questions. It is very informative.

 

Chevy injectors (44.1 psi):

24 lb injectors @ 80% duty cycle support 307 Hp
24 lb injectors @ 100% duty cycle support 384 Hp

Ford injectors on Chevy engine (44.1 psi):

24 lb injectors @ 80% duty cycle support 324 Hp
24 lb injectors @ 100% duty cycle support 405 Hp

Check out the Accel site or do a search in a browser for 'fuel injector rating'.

I recommend using the 80% duty cycle figures. I use 30# in my 390 hp (dynoed) rig just cause I got them cheap.

J

 

Thanks junk....exactly what I needed to know

 

Anyone that has not dynoed their engine will not know its BSFC. Use .5 as an estimate. In real life for most engines it only USUALLY varies between .45 and .55. You have to start somewhere.........5 is a good estimate OR have you motor dynoed to figure it out, but that's kind of expensive for just figuring out fuel injector sizes. It is up to you.
J

 

I think you mean VE (vol. eff.) here? If not, I would hold the pedal to the floor end blow it up cause it is a waste of fuel.

J

 

yeah, sorry

 

If you read the entire entry on the accell website you will also see that a 350 HP 383 TPI needs 19.69 lb/hr injectors, accell recommends the 22 lb/hr. injectors for this setup. So I wouldn't use Junk's information for Fuel Injectors/HP. 24 lb/hr should be good to 450 HP on a TPI.

 

I didn't do any calculations for Accell injectors. Please re-read what I posted. And I would never use Accel's injectors in any engine.
Thanks for the info., maybe the batteries were low in my calculator. I'll have to check them.
J

 

Can you guys put up a link to that Accel page?

 

Here is the link:
www.mrgasket.com/accelpdf/Injector.pdf

J

 

Don't know what you have against Accel injectors, I have 24 # Accel injectors. They are all new, not remanufactured, they are bosch design with improvements and they are flow matched. That's better than some injectors that are twice the cost.

 

I really have nothing against the Accel injectors. I just think that the Ford injectors are a better deal. When I said that I would never put them in any engine, I meant that I would buy the Ford's over the Accel injs. If the Accel injs were way cheaper than the Ford injs I would run them. Just my opinion........probably is based on using a dual points distributor from days past. It is probably a stupid opinion too.
Cheers,
J

 

i got my brand new full set of accell 24#ers off of a guy "fiveomotorsports" for 90 bucks. they have been working flawlessly for several months now, i think he sells them all the time on there (or used to) so you might want to check it out.

 

sofa king how did you get in touch w/"fiveomotorsports"?
Thanks,
Bill

 

sorry, i meant to put he is a guy on ebay.