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Spark plugs for boost with Methanol injection

Joined
28 November 2009
Messages
997
We prefer the NGK Iridium No. 7 (up to 425 bhp) or No. 8 (425 bhp +) depending on power level for boosted NSX. The factory plug has a gap of .044". Gap the plug down from .044" by approximately .004" per 50 bhp added from factory power.

The No. 7 plug comes pre-gapped at .044" and the No. 8 plug comes .032". Adjust the gap carefully as to not break the fragile electrode based on the above information.

http://scienceofspeed.com/products/engine_performance_products/NSX/NGK/NGK_Spark_Plug/


Does this rule still apply for Methanol injection or do you reduce the gap even more?

Taken from SOS website

"
Heat range No. 7 pre-gapped at .044" and No. 8 at .032". Adjust plug gap from factory specification (.044") approximately .004" less for every 50 bhp added. For example: an application adding 150 bhp would require a .032" gap (.044" - .012")."

My plugs are gapped to the stock .044 i believe, i have added around 150bhp as the example suggests, so mine should be gapped to .032" even with methanol in the mixture would .032" still be right?
 
Ordered new plugs, both normal and iridium.

These come pre gapped as .032" i done some research and the -11 in the product code is the difference between .032" and 0.044" recomended by SOS website for my power levels i should gap at .032" but i still don't know if that takes in to account water methanol and if that makes any difference?

Can someone clarify if the same rule applies?

If i do need to adjust, i have purchased the coin looking gauge. This is for measuring and increasing the gap i believe, is the correct method to reduce tap it with a hammer? i've watched a video of this, what if i don't have a vice?
 
I bought my ngk iridium #7 at advance auto for like 25 bucks for the 6. Will, angus, recommend to gap them at .028 for his kit. All I know is that my car is running great with no more issue.
 
I bought my ngk iridium #7 at advance auto for like 25 bucks for the 6. Will, angus, recommend to gap them at .028 for his kit. All I know is that my car is running great with no more issue.

Awesome thanks, i was wondering if is should run a smaller gap.

My tuner recommended .025 but wasn't sure if i could go that low with our cars.

I will give the Iridiums a try initially.
 
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