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Different spark plug gap for performance mods?

Strattos

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Is there a general rule in terms of needing to change spark plug gap greater/lesser once you've modified your motor - specifically head and cam package?

No changes to ignition system in terms of output, purely heads/mild cam and associated supporting mods. Just wondering if with the extra fuel/air there is any benefit or need for different plug gap.
 

07GTS

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not really with n/a just go to a 6 temp rating is fine, its best to keep the widest gap u can for the cylinder fill u have, boosted only needs a smaller gap as there is alot more dense air and fuel in there which can interrupt spark from igniting as well so a smaller gap helps
 

07GTS

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VEGTS BUILT BLOWN E85
not really with n/a just go to a 6 temp rating is fine, its best to keep the widest gap u can for the cylinder fill u have, boosted only needs a smaller gap as there is alot more dense air and fuel in there which can interrupt spark from igniting as well so a smaller gap helps, if u are seeing issues caused by it then just go little closer but if not will be fine
 

MrBags

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not really with n/a just go to a 6 temp rating is fine, its best to keep the widest gap u can for the cylinder fill u have, boosted only needs a smaller gap as there is alot more dense air and fuel in there which can interrupt spark from igniting as well so a smaller gap helps
Hey mate, what plugs and gap would you recommend for a supercharged L77 application.
 

07GTS

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VEGTS BUILT BLOWN E85
Hey mate, what plugs and gap would you recommend for a supercharged L77 application.
boosted i just used the TR6 with there standard gap just check all so they are the same think its 1mm, lasted on e85 till around 15psi then prob tighten to 0.8mm, or if u see issues just go the 0.8 wont hurt or if ur a little richer on petrol, they are a cheap plug so i just change out every 12 months to keep them fresh
 

shane_3800

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I still think gapping plugs tighter is a bandaid on boosted cars. The closer the gap the less volts, the wider the gap the harder it is for the coil to make enougn energy to jump the gap. So the correct solution is to upgrade the coil on a boosted engine.
N/A any non dizzy coil found on a Commodore should be plenty for the street.
 

07GTS

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VEGTS BUILT BLOWN E85
if gaps are getting stupid small on boosted then u know u need better spark, but 0.8 or 0.7 is fine on LS, but at the cost of a little gap verses new coils most just go the gap
 
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