ok, after looking over old posts and talking to many pple i kno, i've basically come to the conclusion that the two most used spark plugs for sohc turbos are the NGK BKR7E and the NGK ZFR6F-11. now the ZFRs look like they are closer to following the "two steps colder" theory when compared to the stock sohc plugs. the BKRs seem to be used more by several b-series setups, but i have seen a few sohc turbos here and there swear by them. which one would be the best plug to run for just two steps down from stock and how much boost would this be safe for? thanks

-alan

 

for 5 psi factory plugs will be ok. 6-10 you need colder plugs. use too cold a plug and you end up fouling them and fuel economy will suffer as will performance.

 

I've been running NGK-R5672A-8(8 range, 2 steps colder) for over two years with no problems. I run 8-10lbs of boost daily, and depending on how I drive, I get equal or better(27-32mpg) fuel economy than I did NA. I was thinking of going to a 7 range plug, but 8 has been working well for me. I change my plugs about twice a year.

 

hey inspyral, think those plugs would do justice for 6-7 psi? i mite be going up to 8, but not too soon

thanks

 

They run fine at 6-7lbs of boost, but you could probably get away with a 7 range plug.

 

8-series plugs would be 3 steps colder for D16's since ours are 5-series sotck

 

I'm running NGK-R5672A-7 (7 range). been fine for the 3 weeks i've been boosting

 

i see that you're both 6th gen civics running similar plugs. are 5th and 6th gen plugs the same? i think maybe i'll try those 7s.

-alan