12psi on 370cc injectors

[sunnys14]

anyone running 12psi on SR injectors + z32 maf? i want to run that but i just wanted to see if anyones run it yet? im running at t3/t4 turbo .50 turbine .63 compressor 57 trim
Modified by sunnys14 at 4:49 PM 9/8/2005

[virus77]

i had a 50 trim and the injectors hit 98% duty cycle around 8-9 psi running a low 11's afr. You might be able to squeeze 10 psi with a flat 12 afr. But the injectors will be screaming for their lives. Get an adjustable FPR and bump the base up a little, it will give you some room to play.

[fabio420]

I hit 14 on 370'cc injectors, but my turbo is way smaller(t3 42/48)

[:: orion ::]

You guys know that boost pressure doesn't mean ****...injectors max out at a certain HP level.

8psi from a T3/T4 with a decent tune *should* be maxing out your SR injectors..at right around 240-250rwhp. That is the absolute, SAFE maximum. Shoot for 260rwhp, say goodbye motor...get it?

So you CANNOT run 12psi from your current setup...#1, you need timing control (what are you using? I'm assuming S-AFC?) and #2, see above.

- Brian

[sunnys14]

i will using msd6 btm for timing control and safc2 to control the injectors.

[NateDogg]

You're asking for *it*.

However, as injectors wear, their max flow rate also increases. I have seen cases where 370cc injectors were flowing 390cc because of their lifespan. I guess the pintle wears a little and allows more fuel past when it opens.

However, you really need to have your particular injectors flowed in order to determine how much power you can get from them at stock fuel pressure.

The only option you have, without going to larger injectors, is to increase the base fuel pressure and then adjust the duty cycle with your S-AFC down in order to accomodate for that in the lower/off-boost rpm.

[sunnys14]

damn... i guess ill stay at 10psi then till i can get ahold of them 550cc's

[Nismo_Freak]

You're asking for *it*.

However, as injectors wear, their max flow rate also increases. I have seen cases where 370cc injectors were flowing 390cc because of their lifespan. I guess the pintle wears a little and allows more fuel past when it opens.

However, you really need to have your particular injectors flowed in order to determine how much power you can get from them at stock fuel pressure.

The only option you have, without going to larger injectors, is to increase the base fuel pressure and then adjust the duty cycle with your S-AFC down in order to accomodate for that in the lower/off-boost rpm.

Nissan has a habit of underrating their injectors.

Case and point are the yellow top 550's.

[hannibal]

Probably not worth pushing it. YOu can add an FPR to wring the last bit out of them. I'd go ahead buy the Deatschwerk 550cc you have in your sig before hitting 12psi...

BTW, you got your comp and turbine housing AR's backwards.

[sunnys14]

BTW, you got your comp and turbine housing AR's backwards.

haha oops!

[GEO]

I am hitting 10psi witht eh 370cc's .. but with a .48 /ar on a t3/t4 57 trim turbo with low 11's high 10's AFR's

[sunnys14]

i think ill settle with 370cc's @10psi for now till i gather up more $$$ later... this car has turned into a money pit!

[ceniack]

see my sig for a good place to get some injectors for a pretty good price, or if you want to keep those injectors, we can flow test them for you, normaly with a 1 day turn around (sent out the next day after we recieve it if it is a week day)

[kae-t]

i was wonderin if i can run about 8psi on a kae without bigger injectors but with a feul pressure regulator and a feul rail or rise something like that

[onosqv]

Hmmm, before I do the tuning, would this work in order to keep it at a safe level around 8-9 psi (to help out w/ boost spikes):

Nismo FPR, bump up base (how much tho?) w/ 370cc & t3/t4. Or would only a RRFPR help?

Right now I have it set nearly perfectly at about 43/35.

I guess what I'm looking for is a little guideline, i.e. Bumping base FPR up to XX, will allow for play of another YY HP, which in this case will help w/ a boost setting or spike of ZZ.

[:: orion ::]

Easy...

Square root of the old pressure divided by the new pressure...that's the base with no vac applied, so 43.5 (3 bar) is your starting point.

4 bar is 58psi base...

So (square root of (58/43.5)) is 1.155...multiply 370cc by 1.155 and you get 427cc.

Easy, simple, done.

- Brian