injectors too big? Idle issues.

  • #1

    injectors too big? Idle issues.

    So I am looking for new injectors I hadd RCeng 550cc before and with my new setup i want to run atleast 750cc injectors. I found a great deal on 1600cc at 53psi injectors that will fit for $120 for a full set brand new bosch.

    I am running a standalone so tunning should be doable. I am thinking with my pressure dropped to around 35-40psi and pulse width narrowed i will be able to maintain a good idle.

    Anyone here running injectors so big they are having idling issues? either with a Nistune or a full standalone. 1600cc is huge and way overboard which is why he is selling them. but its hard to pass up for the price.
  • #2
    Nothing a higher idle couldn't fix
  • #3
    ohh ya there are ways to band aide it for sure. just been digging around the site all day since its raining so hard outside its like a camel pissing on your head, and haven't come across anything just people asking the same ole questions how big for such such hp how much hp from such size will these injectors work, but haven't found anything from someone who has had idle issues due to huge injectors.
  • #4
    I think it depends a lot on the quality of the injector and the spray pattern.. A lot of cheap chinese injectors people seem to have trouble with on the Nistune forums anyway..
    Straya, +61
  • #5
    with your pressure DROPPED to 35-40psi? what is it at now? most injectors are rated at 36psi, the Z31 is at 30 psi at 0 vac/pressure, and 37 at stock boost…

    z31t ran 1600CC injectors on nistune and it was fine.
  • #6
    FSM say 30 @ idle
    37 for NA
    44 for turbo
    Cha iro

    enjoy building it yourself.
    if it fails, fuck it.
    at least you gave it a whirl.
  • #7
    sorry. you're right. its 30 base, 37 at 0 vac, and 44 when it's at 7psi boost pressure.
    doesn't change the fact that setting it down to 35 at idle means it was way high before, though.
  • #8
    If the correct values are entered into NIStune, I'm confident idling wont be an issue. Be sure and set the correct latency, pulse width, and latency change for the injectors and at 30 psi you shouldn't have an issue. Mine are much smaller, but I'm idling just fine which 860cc @ 30psi base fuel pressure.
    Originally posted by Andrew84zx
    tell her your car is so fast it will make her panties fly off
    545 RWHP & 540 RWTQ
  • #9
    not using nistune but it is good to know that it was done with a Tuneable system period. i say dropped to 35 psi as The other bosch injectors i saw rated for 1600cc was at 55psi, and the standard cc measurement is done at 43-45 psi. Granted companies are jacking the pressure to increase the flow rate for sales. I was simply referencing that 1600cc at 55psi would be noticebly less at 35psi, and didn't go into detail.

    They are not chinese injectors they are bosch white/grey top injectors. These are the specs i found based off the part number on the box.

    Latency (dead time): 0.555 ms at 14 volts,

    Injector type: Peak and hold
    Application: Super-street and racing, naturally- and forced-aspirated engines
    Fuel Delivery: Single-hole Pintle
    Spray pattern: Wide cone
    Electrical Connector: EV1, minitimer
    Spray type: wide cone, maximum atomization
    Length: 3 inches, 74 mm
    Diameter: 16 mm
    O-rings: Top and bottom, 14.5 mm
    Resistance: 2.5-3.2 Ohms
  • #10
    I have the same injectors but I am not running them yet. I will once I have my fuel sump and A1000 setup finished. From what I have gathered around the Web they are a gigantic pain in the ass to tune for.
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