I was reading another topic in this forum and it brings up a good question. What size injectors are good for what WHP? I have read a whole mess of different things on this board. Personal Experiences/Discuss

 

Stock fuel pressure

135whp - 240cc
225whp - 440cc
280whp - 550cc
370whp - 720cc

 

Thanks Ben. I needed to know those numbers too.

Those look a little conservative too. Those ratings are probably for around 80% duty cycle (which, IMO, is as high as you would want to go).

 

If I'm looking to make around 200-210 whp with the greddy kit on a LS tuned with hondata s200b, I take it I'm gonna have to ditch the 310cc injectors that came with the kit in favor of 440cc?

 

Thats odd...i swore ive seen people making 300 with DSM 450's....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brianSilverTeg &raquo;</TD></TR><TR><TD CLASS="quote">If I'm looking to make around 200-210 whp with the greddy kit on a LS tuned with hondata s200b, I take it I'm gonna have to ditch the 310cc injectors that came with the kit in favor of 440cc?</TD></TR></TABLE>

Yea you'll have to step up to 440s.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Thats odd...i swore ive seen people making 300 with DSM 450's....
?</TD></TR></TABLE>

I'm sure there are, but they most likely aren't running stock fuel pressures.

 

Which method would be more reliable in the long run, running 310s with an inline fuel pump (or some other method for increasing fuel pressure) or stepping up to 440s and running the stock fuel pressure?

 

i needed this post hehe

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CivicRyda2k &raquo;</TD></TR><TR><TD CLASS="quote">

i needed this post hehe</TD></TR></TABLE>

Yeah this probably helps alot of people out, you can run higher fuel pressure at idle and squeeze some bigger numbers out though

 

http://www.rceng.com/technical.htm

use the calculator at the bottom called "Fuel Injector Worksheet"

 

awesome, thanks for the link.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ben@importparts.com &raquo;</TD></TR><TR><TD CLASS="quote">

"Quote »
"Thats odd...i swore ive seen people making 300 with DSM 450's....?"

I'm sure there are, but they most likely aren't running stock fuel pressures.</TD></TR></TABLE>


306whp DSM 450's stock fuel pressure, walbro pump. Pretty much maxed out

 

just what i did, nothing more....300 whp @12psi b18c1 holly fuel pump, stock fpr. greddy blue box, greddy 310's, 12.4 afr. 5200ft + sea leval. dont know the duty cycle, but it ran fine for 1+ years before i changed it. so, there u go. whatever....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brianSilverTeg &raquo;</TD></TR><TR><TD CLASS="quote">Which method would be more reliable in the long run, running 310s with an inline fuel pump (or some other method for increasing fuel pressure) or stepping up to 440s and running the stock fuel pressure?</TD></TR></TABLE>

You can run:

310cc Injectors + FMU + High Pressure Inline Pump

or

440cc Injectors + Fuel Pump + Electronic Fuel Controller

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brianSilverTeg &raquo;</TD></TR><TR><TD CLASS="quote">306whp DSM 450's stock fuel pressure, walbro pump. Pretty much maxed out
</TD></TR></TABLE>

It's not impossible but you have to worry about seizing your injectors. I love to hear about guys that push the limits as to what everyone considers reliable because it helps us progress. The downside is once you've crossed the line, it's not a pretty sight.