Spark Plugs for turbo e85
 

Hi all

I have a turbo kit about to be installed and the plan is to run on e85 most of the time (Flexfuel with 98 for the occasions where I get stuck without e85 availability). Car is a daily driver with plenty of track days.

Due to some other works its going to be easier for me to do a spark plug change now.

So my question - what plug is best suited for this? Stock or one step colder.

I run a stock plug and make over 700hp

On E85 I presume?

yes I run a delicious tuning flex fuel kit and the car has been straight E85 for 2 years

Stock plugs are good for almost anything

I bought my car 3 months ago. I went turbo at 23K miles. Made 300 wheel at 7 psi on pump. I dont drive the car daily, its mainly a weekend car and a track car, I try to do one track event a month. I plan on going flex fuel/e85 later this year, shooting for 400 wheel. What do you suspect the lifespan of the factory plug is reduced to under these driving conditions? Has anyone tried a different heat range or is it unnecessary with E85? Thanks.

Some turbo kits do recommend using a colder spark plug due to all of the additional heat. I know with the full race turbo kit, they recommend going 2 steps colder; Full race recommend NGK Iridium Spark Plug NGK BKR8EIX or BKR9EIX. Maybe post in the full race turbo kit forum to see if anyone has done it or could contact Eric from Versus (formerly Velox) motorsports as I know he is running their kit on E85 and getting 380whp.