going from #6 to #7 spark plugs..now im running lean????
 

so i just got my new plugs in the mail from xenocron 8) and i was running low 11's afr, and now im running high 12's afr. would it really make this much of a difference???? i have a boosted lsvtec 10:1 compression @ 7psi. thanks

Re: going from #6 to #7 spark plugs..now im running lean????
 

Misfiring could cause your wideband to read "lean", does the car idle all rough?

Re: going from #6 to #7 spark plugs..now im running lean????
 

no it doesnt idle rough...this happens only at WOT. im aiming for mid 11'2 but now with the colder plugs in im getting high 12's...weird

Re: going from #6 to #7 spark plugs..now im running lean????
 

they may be to cold and fouled already.

Re: going from #6 to #7 spark plugs..now im running lean????
 

no, they look brand new but a little white. they were used for literally 15 minutes. i drove the car to the highway and it was lean so i drove home and put my 6's back in. they were part number BKR7e, nGK

Re: going from #6 to #7 spark plugs..now im running lean????
 

bkr7e is what I run, they work great.

Re: going from #6 to #7 spark plugs..now im running lean????
 

White doesn't mean ---- for heat range...you have to look at the ground strap to tell. There should be an annealing mark (or bluing mark) on the strap...if it's heading more towards the tip of the strap your plug is too cold and it's dissapating heat too fast. If it's in the middle of the strap on the curve your heat range is just right, and if it's towards the base at the weld obviously it's too hot. The only way to tell by the plug if you're too lean is to look down inside the well at the base of the ceramic. Too lean will have almost no color or a greyish tint. You want a nice deep brown ring at the base for a boosted motor. I made a post in the engine management section with articles on plug reading...go check them out real quick, they could save your ass down the road.

Re: going from #6 to #7 spark plugs..now im running lean????
 

well they are lean...like i said im hitting high 12's at wot at 7psi. once i saw that i stopped, drove home nicley and put my stock 6's in. they now work great!!! i think i need more power to be using those 7's. weird...i honestly didnt think the plugs would make so much of a differene affecting my afr.

Re: going from #6 to #7 spark plugs..now im running lean????
 

So the original plugs are the same part except the heat range?
BKR6E?

Re: going from #6 to #7 spark plugs..now im running lean????
 

Correct. The "6" designates heat range...most stock dohc vtec's use a "6" range plug to begin with, and most stock D-series call for a "5" from the factory.
The biggest difference with the plug is how far the ceramic sits down in the well...the longer the ceramic, the hotter the plug and the less heat that's dissapated into the cylinder head and cooling jackets. Shorter ceramic moves the heat alot quicker to lower cylinder temps.
BTW, high 12 afr isn't that far off for 7psi...I like a nice 12.5 at that range, any richer into the 11 range and you start fouling plugs and misfiring regardless.