550cc good enough?

  • #1

    550cc good enough?

    So as of right now I have an 88t 300zx, I have 550cc injectors from the FC RX-7. I was wondering if I could up the boost to 20psi and run the injectors safely. Right now it's on 17psi on a really bad base tune. The tune is hot garbage and I want a friend of mine to use the Nistune that's on it.
  • #2
    Do you have a inter-cooler? Are you on the stock T25 or T3 ?
    Own:
    1986 Z31 2+0 Turbo GLL ---- spearco IC ,3" exhaust, Poly everything with solid subframe and diff mounts, HX35/40 Holset Turbo, CLSD, Nistune with 1220cc FIC injectors on E85.
    1993 Jeep Cherokee 4X4
    Owned:
    1995 Z32 2+0 NA Black
    1985 Z31 2+0 turbo Black
    1986 Z31 2+0 NA Red
    1988 Z31 2+2 NA Auto
    1988 Z31 2+0 Turbo White ---- Stripped for all of its goodies.
    1984 Z31 2+0 turbo Brown
    1985 Z31 2+0 NA Black
    2003 Nissan frontier D22 supercharded vg33e 4x4

    Comment

    • BarnFind_Z
      #2.1
      BarnFind_Z commented
      09-09-2019, 07:03 PM
      I'm on a bigger Turbo, the wastegate set on the Turbo is 17psi and I also run a bigger Intercooler, it's at least double the size of the Z32 intercooler.
  • #3
    Depends on your horsepower capabilities of your setup.... Fuel Injector clinic puts you maxing around 440 crank HP assuming stock fuel pressure.

    https://fuelinjectorclinic.com/hp-calculator

    my suggestion… get a good tune first, then check your actual duty cycle (if possible).
    --------------
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    Any information shared is simply my own opinion and NOT the opinion of Nissan

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  • #4
    im running 550CC Grams with vac/reference, they are around 60% duty cycle @ 400 WHP @ 17PSI on a hx35.

    with goals i'd suggest at least 750 or 1000CC for head room and to keep duty cycle low. If you are not targeting over 400WHP 550CC is fine.

    Comment

    • BarnFind_Z
      #4.1
      BarnFind_Z commented
      09-11-2019, 08:18 PM
      Well that hurts, I was hoping to get 420WHP @ 20psi, but maybe in the future I can get that high of a number.
  • #5
    Now if I can't run a 420WHP setup on 550cc, I'd love for people to send me some links for bigger injectors, please and thank you!
  • #6
    Injectors are less complicated than they appear

    Replacing the original connector plugs is highly recommended as the original plastic plugs break down and crack.

    Upgrade to the PastPowerPerformance O-ring rails, find a set of R32 skyline injectors, splice in ev-14 connectors, new gaskets… then do yourself a safety solid and convert your fittings to AN so you don't die in a fire.

    before attempting start-up perform multiple leak checks.

    550CC should safely get you over 400WHP, until duty cycle approaches 80% you're safe - this also relevant to you or your tuners comprehension
    • 1 like
  • #7
    Also remember if convert to E85 you need larger injectors compared to gasoline power goals.
    Own:
    1986 Z31 2+0 Turbo GLL ---- spearco IC ,3" exhaust, Poly everything with solid subframe and diff mounts, HX35/40 Holset Turbo, CLSD, Nistune with 1220cc FIC injectors on E85.
    1993 Jeep Cherokee 4X4
    Owned:
    1995 Z32 2+0 NA Black
    1985 Z31 2+0 turbo Black
    1986 Z31 2+0 NA Red
    1988 Z31 2+2 NA Auto
    1988 Z31 2+0 Turbo White ---- Stripped for all of its goodies.
    1984 Z31 2+0 turbo Brown
    1985 Z31 2+0 NA Black
    2003 Nissan frontier D22 supercharded vg33e 4x4
  • #8
    Do you idle smooth with the large injectors ?.. just asking … . ( jwt 420cc on my t4/t3 turbo no problem ) but what about other larger injectors … ? do they pulse out small amounts at idle ? and then there's what cam is installed …
  • #9
    Smooth idle is largely determined by your setup and tuning.

    If you are competent with K values and idle/warm up trim you should be quite as a honda 4banger at idle
  • #10
    im running E85 on 1200cc injector on nistune. Running a little rich 10-12.1 afr but holds a good idle at 900 rpm. I think 1200cc is already past the limit a little of E85 for decent idle. I had no problems with idle and afr with my previous 450cc dsm blue tops.
    Own:
    1986 Z31 2+0 Turbo GLL ---- spearco IC ,3" exhaust, Poly everything with solid subframe and diff mounts, HX35/40 Holset Turbo, CLSD, Nistune with 1220cc FIC injectors on E85.
    1993 Jeep Cherokee 4X4
    Owned:
    1995 Z32 2+0 NA Black
    1985 Z31 2+0 turbo Black
    1986 Z31 2+0 NA Red
    1988 Z31 2+2 NA Auto
    1988 Z31 2+0 Turbo White ---- Stripped for all of its goodies.
    1984 Z31 2+0 turbo Brown
    1985 Z31 2+0 NA Black
    2003 Nissan frontier D22 supercharded vg33e 4x4