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N54: The best Plugs, Injectors and Coils Thread

Discussion in 'N54' started by doublespaces, Dec 27, 2016.

  1. doublespaces

    doublespaces Administrator

    2009 E93 335i
    Okay its gotten to that point where the influx of newcomers to the platform is rapidly rising and there are several common questions that get asked repeatedly and this will focus on a few maintenance items. For the sanity of the veterans to the platform, it is nice to have threads like these to reference. This post will hopefully answer some of those questions and I will update this as much as possible as information evolves. Lets get to it:

    Spark Plugs (Thanks to @[email protected] for this info)

    BOSCH ZGR6STE2Identical to OE and cheaper
    NGK 95770 (ILZKBR7B8DG)1 Step Colder (FBO+)
    Autolite XP 56821.5 Steps Colder (FBO+)
    NGK 93026 (DILKAR8A8)2 Steps Colder (700hp+)
    NGK 97506 (SILZKBR8D8S)2 Steps Colder

    There have been several revisions to the injectors over the years with Index 12 being the most recent at the time of writing and seemingly the most reliable. There are many places to get these injectors for a significant discount over OE sources, which I will leave up to you to locate. It is important for various reason to ensure all six injectors are replaced at the same time with the same type. You can mix and match Index 11 and 12 injectors with the correct coding, however you may experience bank variances.

    One additional bit of information is in regards to injectors is an extended warranty for certain build dates. See below if you qualify for reimbursement:

    Anyone purchasing new OE coils should wind up getting the new design with the metal housing from Eldor which seem to be a solid choice. There have been a few performance oriented coils such as the Okada Plasma Direct, however its been said that there are better ways to spend that money. There are also many people running the N55 coils by Delphi.

    Eldor #12138657273
    Delphi GN10571

    Upgraded Coils
    There are currently two upgraded coil offerings:
    BimmerLife TuningSmart Coil
    Precision RaceworksDumb Coil


    If any of this information is out of date, incomplete or incorrect please notify me and I will revise it.
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  2. Sweet thread, I am replacing sparks and coils soon.

    I'd love the peace of mind knowing my injectors aren't going to go... but, index 12s are EXPENSIVE lol

    Can you explain the term "colder" (might sound nooby here) I understand that it means the gap difference is different but, why the term "colder"
    Last edited: Dec 28, 2016
  3. ATL-IS-N54

    ATL-IS-N54 Sergeant

    The spark is not as hot and the idea is that it can be advanced without being hot enough to cause pre ignition / detonation and therefore timing corrections etc
  4. ysjeon1698

    ysjeon1698 Specialist

    Is it okay to use one Delph coil and rest with OEM? My one cylinder is off atm and need to replace it soon
  5. Coils can be mismatched. I still like Bosch over Delphi, the boot seems tougher and if they break around the sparkplug it's a pain.
  6. Euro venom

    Euro venom Specialist Girl Club

    I'll always run NGK spark plugs. I've seen Bosch spark plugs burst and melt. Lol
  7. I don't agree there is any consensus on "best" coils. Some people like Bosch, some Eldor, some Delphi. Unless a coil lasts longer, gives better fuel economy, increases power or just costs less how could one be any better then another? They all perform the exact same function. Bosch seem to be the cheapest and are proven to have decent longevity, Eldor is what BMW is using now instead of Bosch and Delphi is just an alternative to the OEM coils. I don't think something should be declared the best without any rationale or metric explaining why.
  8. doublespaces

    doublespaces Administrator

    2009 E93 335i
    This was just the conclusion I came to myself after researching. I've heard about several issues with the boot on the bosch suffering from heat cycling. I think there wasn't a lot of information on the eldor at the time, I've included them in the list.
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  9. mkster08

    mkster08 Corporal

    So I tried the autolite 5682... no bueno, my ngks work great but the autolites throw me into limp for misfires like crazy.. gapped correctly. Do we know a stock heat range ngk plug? Or stock heat that's not a triple electrode?
  10. I was gonna try out Autolites, bought them. Took them back. Got NGK 95770 and gapped to .022

    Car runs beautifully and hasn't had any issues yet
  11. V8bait

    V8bait Sergeant

    I think the 2 step colder plugs should be used for everybody who is tuned, I haven't heard of any fouling issues with them, so they aren't too cold.
  12. Maybe true but, for the most part for the applications a Stage 1+ tuner would need. could easily be supported by OEM replacements, or 1 step colder. That's like saying:

    "I don't understand why anyone with a tuned car doesn't get a Stage 2 LPFP!" at the end of the day... Yes, it would be better anyways but, is it needed for their given setup?
  13. mkster08

    mkster08 Corporal

    So talking to my big hp buddies 1000+ and their tuners they are adamant on running stock heat range even with E85, at most one step colder i.e. Ngk 95770.. do we know of any plugs other than the OE Bosch ones with their heat range that'd work?
  14. doublespaces

    doublespaces Administrator

    2009 E93 335i
    What is the price difference between the two? If they work and cost similar, may as will go 2 steps. If they cost more then I suppose there is a debate, though I can't imagine they would cost much more.
  15. Price difference is low. Either way unless you're moving from Autolites to 97506 then might be 40+ difference
  16. V8bait

    V8bait Sergeant

    Exactly. N55 and S55 are 2 steps colder than OEM to begin with iirc. Heat ranges aren't a very big deal unless you're too hot or too cold, but too hot can be bad. Too cold can misfire and foul if you put around town for short trips and the engine never even gets up to temp, but too hot can cause knock. Since the cars seem to do fine with 2 steps colder I don't see a downside since cost is similar, maybe someone knows more about it though. This is just how I've always approached heat index.
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  17. mkster08

    mkster08 Corporal

    On E85 blends you shouldn't have knock running a stock heat range plug, I'm not saying run the oem Bosch ones, but a replacement which I have yet to find aside from Champion Coppers these should work great but you'd need to change them every oil change. (Only like $2 or so a plug) I'd like to find some ngk iridiums with stock heat range to last a bit longer, if not I'll keep the 1 step colder.. there's no need to run 2 steps colder, you won't make any extra power, and just run the higher misfire and fouling rates.. and lower mpg

    N55 plugs are 1 step colder than n54 stock for stock. The 95770 ngks are a stock alternative for n55
  18. Omar@VaderSolutions

    [email protected] Sergeant Vendor

    NY & AZ
    N54 135i & N54 335i
    Delphi 153 is the one to get
  19. mkster08

    mkster08 Corporal

    For coils?
  20. Omar@VaderSolutions

    [email protected]ons Sergeant Vendor

    NY & AZ
    N54 135i & N54 335i