Adjusting spark plug gap

[Dexter]

Anyone adjust their spark plug gap from the standard 1.1mm? If so, why? Been looking into this online but seem to find conflicting answers. I'm interested for 2 reasons: lower emissions to pass mot and/or better full throttle performance on the track.

[JayTripleR]

I cant see how reducing the gap would change the emissions or give better performance on track i think all that it would do is increase your emissions if anything as it would change the way it butns the fuel / air mixture and cause spark plug to fail prematurely,probably better investing in better spark plugs

[KiNK43]

I run mine at 0.6mm but I have a turbo. So not sure on a stock setup. 

Possible Closing the gap could help mask a failIng item in the ignition system?

[Dexter]

On 9.5.2017 at 10:30 PM, JayTripleR said:

I cant see how reducing the gap would change the emissions or give better performance on track i think all that it would do is increase your emissions if anything as it would change the way it butns the fuel / air mixture and cause spark plug to fail prematurely,probably better investing in better spark plugs

 

That's exactly what i'm interested in, to find out how performance is affected by changing the way fuel/air mix burns. I've been running NGK iridiums and regulars so don't think i require an upgrade from that. Once source i found claimed that constant high-rev performance eg. track would improve by closing the gap 10% from stock, but i'm skeptical.

 

1 hour ago, KiNK43 said:

I run mine at 0.6mm but I have a turbo. So not sure on a stock setup. 

Possible Closing the gap could help mask a failIng item in the ignition system?

 

Yes i've heard that turbos require smaller gaps. That's the only consistent info i found. I do have high emissions at the moment that are possibly caused by something wrong with the ignition, obviously i want to fix that as well but still interested in looking at all of the cards first.

[noodels]

This is for my S2000

Adjust plug gap from factory specification (.044") approximately .004" less for every 50 bhp added. For example: an application adding 150 bhp to the factory 240 bhp would require a .032" gap (.044" - .012").