Like the topic asks, im looking to know what other FC turbo owners feel is the best spark plug to run on a stock 13b-t engine with many "bolt ons". Any part numbers would be helpful if anyone knows them off the top of there head. Also how often do most of you change your plugs? Thanks

 

bur9eq x4 . with most bolt on's and slight increase in boost
chenge them as often as pep boys will warranty the plugs. ngk has life time defective replacement. keep the boxes and talk to a manager. need to cool about it but it works.

 

9 all the way around?
Stock is 9/7 for trailing/leading or vice versa.Will this effect timing/boost rich/lean?

I usally run colder plugs than stock,But Im not sure on going from 7 to 9.
I buy my NGK from Discount/advance auto and they do have a warrenty,But I usally clean my own plugs once a month if im not lazy.

 

9s all the way around will work fine, thats what I use now. I used to run 10.5/9 but they tend to foul a little easy with daily driving and big injectors. It's a good idea to go as cold as you can get away with.

 

plugs have no impact on timing or true a/f ratios

a "colder" will transfer heat quickly into the surrounding engien material and coolant. thus keeping the tip a bit cooler and being less likely to pre-ignited the mixture. this is why the trailing plugs are stock 9 (colder) than the 7 in the leading as they fire later but in a hotter spot of the combustion event

9s all around is a common thing. as is the big boost single guys running the pain in the ass snowmobile plugs that are 10.5