sparq

I was wondering how good stock D series SOHC non vtec injectors were - like upto what HP rating they were good for? And if maybe someone could give me a little help as far as how to pick a set of injectors for various HP on the mighty D

mpg9999

(Injector flow rate x # of injectors x .8)/BSFC= aproximate engine hp the injectors are capable of.

BlueShadow

here is something that I posted in another thread:

EDIT keep in mind these are the max HP the injectors would support at <u>100% duty cycle and at ~40 PSI fuel pressure</u>. If you are controlling the injectors with a standalone, find the injector size that closely matches your HP goal AND SELECT THE NEXT INJECTOR SIZE ABOVE IT.

since the HP numbers are at the max duty cycle, you would want to lower the duty cycle that the injectors operate at...and when you do that you are lowering the amount of HP they will support.

does all that make sense?


https://honda-tech.com/zerothread?id=373764

270cc = 187 HP
310cc = 214 HP
320cc = 220 HP
370cc = 256 HP
400cc = 277 HP
440cc = 304 HP
450cc = 311 HP
500cc = 346 HP
550cc = 380 HP
600cc = 415 HP
650cc = 450 HP
800cc = 554 HP
880cc = 609 HP

Yes they are in WHP (BHP actually), but they are only estimates. And those HP numbers are if the injectors are run at 100% duty cycle at about 40 PSI fuel pressure.

It's all in Maximum Boost, here is the formula:

[(expected BHP x 0.55) / number of injectors] * 10.5 = CC size of injector

EDIT: and I just wanted to repeat my disclaimer that you should not use my numbers as a sole guide to selecting injector sizes.





[Modified by BlueShadow, 7:50 PM 1/6/2003]

Pengo

why did you use 100% duty cycle for your equations? i thought 80% was the industry standard? just curious as to the numbers used. thanks

BlueShadow

because the calculation I used from Maximum Boost seems to calculate it to 100% duty cycles.

one of the members on preludeonline.com was using 440s at 70% duty cycle and making ~250 HP at higher than stock fuel pressure, when we did our calculations at 100% duty cycle the max HP was ~304 HP. You can add another factor in there that calculates the 100% duty cycle value to 70% or 80% duty cycle if you wanted.


[Modified by BlueShadow, 10:14 PM 1/6/2003]

racerxadam

how about an online calculator that you can input:
expected hp
bsfc
duty cycle max.
rail fuel pressure
number of cylinders

http://www.rceng.com/technical.htm
toward the bottom

Elite Hatch

Thats such a vauge question. I have seen 440cc injectors pullout over 400hp easy. But I have also seen 440cc injectors lean out at a lot lower than that.

BlueShadow

what fuel pressure were they running at? you can get more fuel (therefore more HP) out of an injector when you raise the fuel pressure.

Elite Hatch

obserdly high

sparq

AWESOME! Thanks for all the links and help guys - ill be book marking all this for later use

Since I STILL can not sell my POS I think im just going to turbo it to holy hell and drive it till it dies. Or maybe ill throw it up on ebay after its "complete" cause I know ill for damn sure get more then $1500 for it. BLAH, looks like 370cc injectors for me