Is that the correct step up for the NGK copper plugs.(1 step colder) 50-75 dry shot? I looked through the NGK catalogue @ work, the the website, but it seems itd be a ZFR7F-11, yet Im not seeing anything. What do the prelude/nitrous guys use as far as plugs go?

 

Stock plugs on a H22A1 are ZFR6F-11. Stock on H22A4 are PZFR6F-11, P for Platinum(you can use copper anyway). One step colder would be ZFR7F-11. Some people use a different NGK plug, but I'm not sure what it is, or what the difference is.

If you want the ZFR7F-11's, I have them in stock for $2.07 per plug plus shipping.

 

I know the PZFr...I use copper for the spark purposes. Anywho, I figured the way the numbers go when going colder, just that I didnt see them listed anywhere so I dunno if there was a different listing for the part number. If I didnt work @ a parts store and have us sell NGKs for <2.00 - 20% discount I might take you up on your offer.

 

The one step colder plugs are ZFR7F-11. The part number is 2975. These have the extended electrode. I'm using them for forced induction.

 

you= rock. Thanks for that Pt. #

 

Many people use the ZFR7F-11 on the H22 with just bolt-ons.

 

I'm bout to get new plugs also, just wondering what the part # is for the NGK plugs 1 step colder for an H23?

 

same I believe

 

BKR7E, get them from summit.