How much whp can nismo (not GTIR) 444 injectors support at 3 bar and at 4 bar, I want to use these injectors instead of the 370 injectors for an upcoming turbo project.

very rough guess... I think the 370s can do about 250 crank hp at 3 bar.... assuming everything is linear, 444s can do 300 crank at 3 bar and 400 at 4 bar.... that's a big assumption though!

@3bar
370cc=35.2lb x 4 x .85 / .5 = 239whp
444cc=42.2lb x 4 x .85 / .5 = 286whp

@4bar
370cc = 4 bar / 3 bar = 1.351 = sqrt 1.162 x 370cc = 429cc
444cc = 4 bar / 3 bar = 1.351 = sqrt 1.162 x 444cc = 515cc

370cc@4 bar = 429cc = 40.8lb x 4 x .85 / .5 = 277whp
444cc@4 bar = 515cc = 49.0lb x 4 x .85 / .5 = 333whp

Horse Power Support
370cc@3bar = 239whp
370cc@4bar = 277whp

444cc@3bar = 286whp
444cc@4bar = 333whp

I heard that the Nissan 370cc injectors are closer to 390cc so I sure a little more HP can probably be had, if you really want to find out ask RC whats the norm that 370cc bench flow or send your own and find out.

Hey Charlie, I was close! Not too bad for 3 hours sleep last night and a cell phone calculator :)

Originally posted by spdracerUT
Hey Charlie, I was close! Not too bad for 3 hours sleep last night and a cell phone calculator :)

Yeah, that was pretty good.:D

Originally posted by charlie2020
@3bar
370cc=35.2lb x 4 x .85 / .5 = 239whp
444cc=42.2lb x 4 x .85 / .5 = 286whp

@4bar
370cc = 4 bar / 3 bar = 1.351 = sqrt 1.162 x 370cc = 429cc
444cc = 4 bar / 3 bar = 1.351 = sqrt 1.162 x 444cc = 515cc

370cc@4 bar = 429cc = 40.8lb x 4 x .85 / .5 = 277whp
444cc@4 bar = 515cc = 49.0lb x 4 x .85 / .5 = 333whp

Horse Power Support
370cc@3bar = 239whp
370cc@4bar = 277whp

444cc@3bar = 286whp
444cc@4bar = 333whp

if you know any html you should make a page that can compute that kind of thing so TONS of people can use it and not have to ask. Just a thought. I think it would be a great idea.

Here goes a link but you have to do your own math I haven't ran accross a link that does it for you, and this doesn't have the formula to calculate raising FP but instead it has a general guideline to specific injectors at certain bar psi's.

http://www.grapeaperacing.com/GrapeApeRacing/tech/fuelinjectors.cfm

Frm the RC Engineering website (http://www.rceng.com/technical.htm#WORKSHEET)

I had some 370 tested and they came out at 390ccs from RC Eng, I had the flow chart somewhere on my computer. Thats how I found out they where not claimmed 555cc Nismo injectors but early Z32 TT injectors that someone swapped into the boxes before I got em.

@ What PSi are these measured? RC tests them at 43 psig.

I was wondering, if I get a GTIR ecu, I could just use thier 444cc injectors without having to do anything else... I actullay want some injectors that are peak and hold rahter than saturated injectors.

Peak and hold are cheaper when you get to higher hp requiring larger than 370cc. Plus most powerful engines run peak and hold stock.

Just about all injectors are measured @ 3bar I know all Nissan injectors should be.

if thats the case then for about 280whp i'll use 370cc injectors at 4 bar. I'll get bigger ones if/when I get a bigger turbo

Thats exaclty what i'm taking about, besides running at 4bar is not that hard on the injector anyways, its should be able to last just as long at 4bar as it would 3bar. I wouldn't run anything higher than 4bar............well it really wouldn't matter I only have the stock T-25 anyways.

well i'll have at t28, with s4's and 2.5 turbo back, no cat