by them selfs NON. but if your experiencing Knock Retard (KR) then depending on how many degrees of kr you have will determin the gain.

id venture to guess 0-2 prob about 5hp 3-5 10hp and if your tuning the car and can pull additional spark advance out of the motor you can possibly pull more... let alone being able to run a smaller pulley on top of the spark gains.


the colder plugs im runing in my Z34 are there cause i retuned for a more agressive spark table. and then 180 stat does wonders for me down here in the florida heat.