High Boost spark plug heat range

  • #1

    High Boost spark plug heat range

    Hi,

    As I'm doing some upgrades to my 88 Z31 I was wondering what the best choice would be regarding spark plugs. Especially the heat range.
    I know stock is 6 but with increased boost I probably need to go up to 7 or 8. Just don't know what would be the best guess to start off with and not having to worry about detonation from my plugs but still having a good running car.

    I'll do a little write-up on my build soon but these are the basic upgrades I'm doing.

    - Holset HX35 Turbo
    - 550cc Rx7 injectors
    - FMIC
    - 3" exhaust
    - Autronic ECU.

    Im looking to run about 20 - 22 PSI of boost on 102 octane pump gas (would like to run 98 oct but I'm starting off with 102 to be safe)

    Would like to hear from the experience you guys have.
    Thanks!
    Last edited by RoyH; 04-22-2018, 04:03 PM.
  • #2
    Where in the world are you finding 102 octane pump gas? The highest available here is 93.
    --------------
    Legal stuff:
    **Nissan Employee**
    Any information shared is simply my own opinion and NOT the opinion of Nissan

    not legal stuff:
    '88 300ZX 2+2-- driving… just details left
    '22 Q60RS-- I tell the wife it's hers…
    '87 Chaparral bowrider-- the next project
    '00 Corolla-- kids car.
    '14 E-350-- Gotta haul those kids in something.
  • #3
    Originally posted by mwolvinm View Post
    Where in the world are you finding 102 octane pump gas? The highest available here is 93.
    The netherlands http://competition102.com/en/

    we used to drive just across the border to germany and fill up with e85 which is even better but not available anymore.
  • #4
    Ahh. That makes sense. 102 isn't available at the pumps in the USA. However, E85 is. I just don't dare put E85 in the car.
    --------------
    Legal stuff:
    **Nissan Employee**
    Any information shared is simply my own opinion and NOT the opinion of Nissan

    not legal stuff:
    '88 300ZX 2+2-- driving… just details left
    '22 Q60RS-- I tell the wife it's hers…
    '87 Chaparral bowrider-- the next project
    '00 Corolla-- kids car.
    '14 E-350-- Gotta haul those kids in something.
  • #5
    I use a heat range 7 NGK Copper Plug gapped at .028. I don't have any issues whatsoever with spark blowout at 20+ psi on my current setup. I've pushed as much as 28 lbs on my old T3/T4 which flows similarly to the Holset.

    I've ran this plug heat range and gap on 93 Octane, 117 Octane. And E85 all with success. Currently running E85.
    Originally posted by Andrew84zx
    tell her your car is so fast it will make her panties fly off
    545 RWHP & 540 RWTQ
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