E85 And Spark Plugs

[Piggaz]

Hey guys. N1GTR and I were in my car today and i noticed sometimes that my car was missing. It sounded and went exactly like it was when my plugs were fouled, I changed them and bingo back to its normal self. Now I changed plugs the other day and have only done 150-200 kms since. I put in BCPR9ES-8. Im starting to think that the 9's are a little cold for E85. I had the same plugs in when it was on 98 and it never had any issues what so ever. Should I drop back to a heat range 8? I gave it a little splat on the way home and it felt fine. So I suppose my question is what plugs do guys use on E85 with 400+rwkw on tap?

[rob82]

In a street driven car with 400rwkw on tap with an rb26 I would be using a maximum of BCPR8ES on pump. You could go up to a 9 if your at the track - however on e85 I would be definately going back down to a 7 as in most cases you will drop 100deg C chamber temps. Usually on E85 you can go up in plug gap too as the extra ignition timing puts less stress on the ignition system.

[Piggaz]

Yeah fair call. I was speaking to the tuner a while ago when it was getting tuned on 98. He said if you have no starting issues and no fouling issues on the 9's its fine. I'll whack the 7's in and see what happens.