So true about the backfiring, but mine does it on the street.Nay not as loud but it does back fire a bit on the track. I haven't done the keen mod yet though
Is the keen mod you speak of removing the oxygen thingy inder the tank and putting block off plates on? I was reading up on that on other forums and apparently it stops the popping and backfiring.
May as well order the plates anyway as I will be getting a PCV tonight. God bless the USA and its shitty dollar atm.