Log in

View Full Version : possible power from stock injectors


bsilvias13
03-25-2008, 01:53 PM
So after looking around (briefly) i havent noticed anything that can answer my question. so here it is i have a sr20det redtop in my car (http://www.zilvia.net/f/showthread.php?t=183790#) i have the following items.

fmic
type rs bov
removed a/c
full 3" exhaust
polished turbo manifold
3"downpipe
3"testpipe
s14 water pump
custom intake
walbro 255
apexi neo
and new gt2871r dual bb turbo

i am modding my turbo by removing that internal gate and running a tial 38mm external gate with dumptube and im gonna run aprox. 19-20psi thru this set up. and running 110 fuel too.

so my question is how much power can i get from the stock injectors?
im going to get a fuel pressure regulator too of course.

my goal is 300 (http://www.zilvia.net/f/showthread.php?t=183790#) whp on the stock motor and internals on this setup is that obtainable. im assuming yes but just wanted to know what i can get thru stock injectors.

any help would be great thanks guys.

brokeAs240sx
03-25-2008, 04:39 PM
Google is your friend - you can calculate that by searching google... "injector size horsepower", or something like that...

I got this:
http://www.rceng.com/technical.aspx

and

http://www.injector.com/injectorselection.php

That being said, stock injectors "shouldn't" allow you to go up to 300whp w/o going some crazy rising rate fpr/fpu.

For goal of 300whp, I would say go w/ some 740cc.

jspaeth
03-25-2008, 04:52 PM
You really need to do some research man.

With that size turbo at that boost, you are gonna need 740cc or larger injectors and will get you way more than 300 hp.

Running stock injectors with that turbo is ridiculous.

Get some help before you blow up your car.

garagelu
03-25-2008, 04:58 PM
550cc injectors will hold up to about 350-375 hp. I am pushing 323 hp on my 2871r and still have a lot of room on my injectors. Next is cams and I bought a fuel pressure regulator in case my injectors run out of room.

Skids2212
03-26-2008, 12:08 AM
do the math

122ci x lets say max power at 6500 rpm x .9 Volumetric Effieciency x 2.36 pressure ratio/ 3456 = CFM motor will flow = 487.36 cfm

now take 487.36 cfm x .44298 / by 4 cyl = lb/hr injector size = 53.97 lb/hr x 10.5= 566.685cc i would get 740cc injectors to be safe.

if you wanted to run stock injectors

you would need to at least triple the fuel pressure and that would put you at about 130 psi have fun


/nerd

bsilvias13
03-26-2008, 04:29 AM
You really need to do some research man.

With that size turbo at that boost, you are gonna need 740cc or larger injectors and will get you way more than 300 hp.

Running stock injectors with that turbo is ridiculous.

Get some help before you blow up your car.
yeah ive got pros tuning it etc. i just wanted to make sure i show up with everything they will need to make it easy on them.

bsilvias13
03-26-2008, 04:35 AM
thanks for all the help guys this site seems more and more helpfull eachtime i need help. (repetative, but u get it)

-peace-

johnw1415
03-26-2008, 06:46 AM
I would put in a headgasket and some arp studs, then ditch the neo, you could get 350 or more with a good tune, and you wouldnt have to use race gas