Anyone use different spark plugs?

    For the Alpha turbo kits we are using one of the below set of plugs...


    • Iridiums that come with turbo kit - NGK: BKR7EIX11
    • Copper / Standard Option - NGK: 92038 - LFR7A


    If you are going to run anything different, pay special attention to the heat range, gap, and length of the plug. I was running some other NGK 7 heat range plugs, but realized they were much shorter than what should be in there.

    Owner of Slingshot #263 that has some stock parts left on it. :D

    Quote from TravAZ

    For the Alpha turbo kits we are using one of the below set of plugs...


    • Iridiums that come with turbo kit - NGK: BKR7EIX11
    • Copper / Standard Option - NGK: 92038 - LFR7A


    If you are going to run anything different, pay special attention to the heat range, gap, and length of the plug. I was running some other NGK 7 heat range plugs, but realized they were much shorter than what should be in there.


    Those BKR7EIX-11 plugs are not really the same as the stock plugs, they have a different seat style and also are short on the reach.


    Here is the stock spark plug information from NGK's website for a 2006 Solstice with a 2.4L LE5 - NGK 4344 LTR5IX-11 Iridium Spark Plug



    Shell


    2 things that I want to point out on that list - Set type and Reach.


    Now if we look at the NGK site for the BKR7EIX-11 - NGK 6988 BKR7EIX-11 Iridium Spark Plug here is the description -



    Shell


    In the description from NGK it is showing that those are Gasket seats and also only 19mm of reach.


    The LTR6IX-11 plugs are a much closer fit to the stock plugs since they have the following specs - NGK 6509 LTR6IX-11 Iridium Spark Plug



    Shell


    Same seat type and also the same reach.


    The other plug you referenced - LFR7A - NGK 92038 LFR7A Spark Plug



    Shell


    That plug has a gasket seat instead of tapered seat, the reach on it is actually a little long, although the tighter gap is good for high boost applications (over about 12-13psi).


    Hope that helps,
    Dave

    Quote from Street Doc

    So maybe a LTR7IX-11 going one step cooler?

    The stock heat range is a "5" with NGK. Different spark plug manufacturers note heat range differently, but with NGK the higher the number the cooler the plug. So a "6" is going to be 1 step cooler and a "7" is going to be 2 steps cooler.


    BTW - the "-11" at the end of the numbers on these plugs designates the gap in millimeters, -11 means a gap of 1.1mm as shipped from NGK (about .043")


    That is why we sell and install the LTR6IX-11 on all of the forced induction kits we sell, it is basically exactly the same shape as the stock plug, just one heat range cooler. The 7 heat range might start being a good idea if you start going over 350hp at the wheels, most spark plugs manufacturers recommend 1 step cooler for every 75hp or so. The downside of going too cold of a plug though is that they are more prone to fouling if you are not running them hard all of the time. For most people we find that the "6" heat range works well.

    Quote from MACAWS

    The Hahn Turbo set up recommends NGK 4306

    Here are the details on this plug. Seems like a hot plug to me when pushing over 250hp. I would also think the gap is pretty large...

    Product Details



    Part Number: 4306
    Weight: 1.19lbs
    Center Electrode Core Material: Copper
    Center Electrode Design: Standard / Regular
    Center Electrode Tip Material: Nickel with V Groove
    Drive Size: 5/8 in
    Gap - Factory Preset: 1.3 mm = 0.052 in
    Ground Electrode Configuration: Single
    Ground Electrode Tip Material: Nickel Alloy
    Insulator Material: Ceramic
    Insulator Type: Projected
    Manufacturer Heat Range Number: 5
    Package Quantity: 1
    Reach (in): 0.98
    Resistor: Yes
    Seat Style: Tapered
    Thread Size: 14 mm

    Owner of Slingshot #263 that has some stock parts left on it. :D

    Quote from TravAZ

    Here are the details on this plug. Seems like a hot plug to me when pushing over 250hp. I would also think the gap is pretty large...
    Product Details



    Part Number: 4306
    Weight: 1.19lbs
    Center Electrode Core Material: Copper
    Center Electrode Design: Standard / Regular
    Center Electrode Tip Material: Nickel with V Groove
    Drive Size: 5/8 in
    Gap - Factory Preset: 1.3 mm = 0.052 in
    Ground Electrode Configuration: Single
    Ground Electrode Tip Material: Nickel Alloy
    Insulator Material: Ceramic
    Insulator Type: Projected
    Manufacturer Heat Range Number: 5
    Package Quantity: 1
    Reach (in): 0.98
    Resistor: Yes
    Seat Style: Tapered
    Thread Size: 14 mm

    That was the luge recommended and I have 6K on the system no issues
    We can check wit rabtech - he runs the same set up not sure what plug he uses
    I would have to go back and check the recommended gap but it is not that big for sure

    The more people I meet

    The more I love my Dog!

    On mine I used a factory GM iridium tipped plugs. They are the one out of the LNF. 41-108. Same heat range as the NGK TR7IX. Stock gap which should be .043". Do not use the ones out of the LSJ as they are too long and will hit the piston!

    Since the stock NGK non-iridium spark plugs are LTR5GP, then the 6 heat range plugs would be an LTR6GP, but that is not available from NGK, neither is a LTR7GP.


    That plug that was listed for the HAHN setups is a LZTR5A-13 and so the 6 heat range would be a LZTR6A-13, which is not available either.


    I would have to do some searching to come up with a copper plug with a 6 heat range in the same length, nothing right off though. As for the iridium causing detonation, that is not something that we have seen at all, typically it works really well since the tip is so small on the iridium it runs cooler at the tip and is less prone to detonation.

    Quote from Bugzilla

    On mine I used a factory GM iridium tipped plugs. They are the one out of the LNF. 41-108. Same heat range as the NGK TR7IX. Stock gap which should be .043". Do not use the ones out of the LSJ as they are too long and will hit the piston!

    Are you sure about that heat range on the LNF spark plugs? We have always been told that the stock LNF spark plugs after 2008 are a 5 heat range, NGK's site also crosses the 41-108 over as a heat range 5 - ILTR5C11, I have never seen them listed as a "7" heat range. Thanks!

    @Dave@DDMWorks


    I agree. I have not seen any detonation issues with the iridium plugs. I actually think they help with detonation. It is more of a spark plug heat range issue that will cause detonation to happen. (or just a bad tune)


    Non iridium plugs that would be comparable are the NGK TR7 for boosted and the TR6 for NA applications. Some people even use the TR55 for NA applications. Not sure what the 4 digit part numbers are off the top of my head.

    Quote from Dave@DDMWorks

    Since the stock NGK non-iridium spark plugs are LTR5GP, then the 6 heat range plugs would be an LTR6GP, but that is not available from NGK, neither is a LTR7GP.


    That plug that was listed for the HAHN setups is a LZTR5A-13 and so the 6 heat range would be a LZTR6A-13, which is not available either.


    I would have to do some searching to come up with a copper plug with a 6 heat range in the same length, nothing right off though. As for the iridium causing detonation, that is not something that we have seen at all, typically it works really well since the tip is so small on the iridium it runs cooler at the tip and is less prone to detonation.


    I guess through my experience so far, it has been actually backwards on my machine.


    I have been told this by a trusted source, but I am not sure what value it holds. Paraphrasing what he told me below...

    "Iridium plugs tend to heat up much faster under full boost conditions because of the small tip. It is like heating up the pointy end of the pencil instead on the eraser end. You can easily see which one will get hotter faster. Because iridium gets so hot so fast under full boost, we will see many machines on the dyno have detonation issues and also make less power. On the positive note, iridium plugs will last much longer in boost applications compared to "standard" copper plugs."

    Another internet source on the subject... (is it reliable, who knows...?)

    "I have kept quiet for a long time about the iridium plug debate on here but I am going to throw in my $.02... These findings are based on on-time data logging and research on a turbo'd 400whp audi a4 (2871R).


    Copper is one of the best conductors of electricity and heat, but they just plain dont last mileage wise. Iridium & Platinum last 10 fold longer thus the reason why auto manufactures use these. Coppers can last 5K miles if the engine is operating optimally. Platinum and Iridium plugs have a center electrode (fine-wire) that is thin. Under high boost application they get so hot they will begin to "heat glow" and cause premature ignition in the combustion cycle (pre-ignition => detonation) unless they were properly designed to pull the heat. This is a problem for all of the turbo guys running high boost. Copper on the other hand, has a much thicker center electrode, on top of that, the copper material is able to dissipate heat from the combustion chamber fast enough to keep the combustion temperatures lower. Coppers use thicker electrodes simply based on the fact that they can easily jump the spark, whereas platinum and iridiums will require a fine wire to better direct the spark to prevent misfires.


    Remember the TWO primary functions of a sparkplug:
    1) To efficiently ignite the A/F mixture without misfires (gap..etc)
    2) To pull heat from the combustion chamber into the head, where the cooling system should dissipate that heat. (Heat Range)


    A platinum/Iridium plug in a colder heat range usually runs just as hot as a copper in the standard heat range when under high stress. So many people will use a Platinum/Iridium plug TWO steps colder to counter that. But using a plug that is 2 steps colder, will lead to two things:


    1) More prone to carbon-fouling on "normal driving" where EGT's are kept low. (Plugs must stay above 550C Deg to burn off excess carbon deposits to "self-clean")
    2) As a result, loss of horsepower from a less efficient/inhibited spark.


    You need a plug that is actually "hot enough" to ignite the A/F mixture as hot as possible to get the most efficient combustion, as well as burn off carbon-deposits (~550C deg), and yet cold enough to prevent pre-ignition when compression is high (< 870C Deg)."


    The real test for me is going out and driving my machine hard with the new copper plugs installed. I am pretty sure this is the fix, but won't know until I get up really early and drive it or go out in the 100-115 degree heat. If I don't hear detonation, I will stick with the copper plugs and be OK with changing them every 10,000 miles or so.

    Owner of Slingshot #263 that has some stock parts left on it. :D

    Quote from Dave@DDMWorks

    Are you sure about that heat range on the LNF spark plugs? We have always been told that the stock LNF spark plugs after 2008 are a 5 heat range, NGK's site also crosses the 41-108 over as a heat range 5 - ILTR5C11, I have never seen them listed as a "7" heat range. Thanks!

    I am pretty sure they are in the 7 heat range. I thought the 41-105 was the one in the 5 range. Physically looking at the 41-108 plug and comparing it to a NGK #7, they look almost identical.

    Quote from Bugzilla

    @Dave@DDMWorks


    I agree. I have not seen any detonation issues with the iridium plugs. I actually think they help with detonation. It is more of a spark plug heat range issue that will cause detonation to happen. (or just a bad tune)


    Non iridium plugs that would be comparable are the NGK TR7 for boosted and the TR6 for NA applications. Some people even use the TR55 for NA applications. Not sure what the 4 digit part numbers are off the top of my head.


    @Bugzilla the NGK TR7s are most likely too short.

    You will be in the same boat I was when I switch my plugs the first time and didn't realize the "reach" difference. Good thing I didn't mess up the head at my last track event. TR7 specs below...

    Shell


    Owner of Slingshot #263 that has some stock parts left on it. :D

    Thanks for the correction. Was at work and had LS brain going on. All ecotecs use the same length plug except the lsj which uses the shorter LS style plug. The TR series plugs will work in the lsj not the 2.4s. I believe it is the LTR series that would be the correct ones.