forgive my ignorance but I am kind of new to the whole gapping of the spark plugs. I switched my spark plugs to ngk bpr8's and once installed I found that the car was a lot slower than before. At the same time I also had the my engine flushed and cleaned by the dealer. Now I believe that the dealer would have disconnected the battery for this. Do you think it is poorly gapped spark plugs causing the lack of power. The car does have a flash on the ecu.

 

do a log.

wrong gapped plugs will cause knock = timing being pulled = slower

 

Gap on plugs is one of the biggest things to know on a evo. .26 to .28. Those plugs are good but they will need replacing every 5000 miles. Spend the money on iridiums and youll get 15,000 miles out of one set of plugs.

 

If your going to mod the car out, get rid of the iridiums! I would just ditch those anyway.... Run the BPR8ES gap them at .024

 

so what's the gapping on yours?

 

Absolutely man. Play with them and see what works best for you.

 

thanks for the help. I will be in chicago on friday and really close to ams location. might have them take a look at my tune while i'm there. A check up is never a bad idea anyway.

 

ditto. i just put some fresh ones in and gapped to .024 and the car feels much smoother and pulls a little harder from by butt dyno.
The prev owner had them gapped at like 35-36 i wanna say. ran well, but noticed some little breakups lately until I put new plugs in

 

again forgive my ignorance. What tool do you use to adjust the gapping.

 

A spark plug gapper. $.79 at an auto store.

 

just get a feeler gauge and gap your plugs, it's easy and simple and dose a BIG affect on the tune

 

had sorta simliar problem at my tune, my plugs were burnt though at the top and causing knock which then you have to pull timing to make the ecu happy which makes less power

 

""At the same time I also had the my engine flushed and cleaned by the dealer.""

engine flushes are questionable, they don't deliver all they claim.

""The prev owner had them gapped at like 35-36 i wanna say''"

yeah, cuz that's what they come gapped at new, it's a good setting for NA but not for boost

 

Agreed. I usually gap turbo cars in the mid 20's and they work great for me.

 

thanks for the help guys. will pull my plugs tomorrow and get the gapping tool.