I am in the middle of a rebuild and I have fome to the point where I want to change my Injectors from the last setup I had. I am using http://www.2gnt.com/www/corbin/chooseinj.html and am coming up with something I think is a little off and wanted a second opinion.

To give a little background rebuild consists of
Wiseco 8.8:1 .020
Eagle Rods

Currently have installed
Stage 2 HRC Turbo (looking to run 16 - 19psi once done)
SFMU
Walbro 255 LPH
Accel 30# (looking to upgrade)

Now after doing the calculations for the HP X BSFC X 10.5 (300 X 0.525 X 10.5)I get 413.43 for the fuel rate. I am ok with that. Now getting to the duty cycle is where I am getting a little confused. I understand that we need to divide the flow rate by the max duty cycle but when I divide 413.43 by 85% for the max duty cycle, I get 486.38. Does that sound right? I am thinking when you divide a number the sum should be smaller.

2nd question I have comes in dealing with the differential pressure and fuel pressure. I have no idea what the proper fuel pressure should be at full throttle to run 16 - 19psi of boost so getting the differential pressure is kind of difficult. Can anyone help me out with this please?

http://www.cardomain.com/id/hunntyr


(\__/)
(='.'=)
(")_(")

hahah dude you totally failed math

If you divide by a number greater then 1 it will get smaller, if you divide by 1 it won't change, and if you divide by a number smaller then one or a percentage it will get bigger, so 485 or whatever you got sounds about right

Differential pressure means that the actual fuel pressure is the rail pressure minus your boost pressure.. so if your rail pressure was to maintain itself at 45psi without changing, but your boost pressure increased to 15psi, you suddenly only have 30psi of fuel pressure

You have a SFMU so it rises with boost to maintain or increase your differential fuel pressure.

1995 Eagle Talon ESi

LOL...I knew I was off somehow. Thanks for the clarification.

http://www.cardomain.com/id/hunntyr


(\__/)
(='.'=)
(")_(")

I have 440's, although I use the Megaquirt, i've run up to 18-19 psi on them, and the duty cycles are maxed out..Its in the low 90% range at full boost and full load. I'd say you need at least 440's, but an injector in the 500 cc range would be just fine. I really wouldnt reccomend running just an SFMU with that large of injector though..Time for a Megasquirt!

13.5 @108 MPH-2.2 60ft(stupid FWD!)
S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential
fuel injection)
My webpage: http://eclipsed4evr.home.comcast.net
-1998 Mitsubishi Eclipse RS-T- "Toy"
-1992 Plymouth Laser Turbo AWD(SOLD)
-2000 Honda CR-V(daily)

http://www.cardomain.com/id/hunntyr


(\__/)
(='.'=)
(")_(")