I live at 500' above sea level I'm going to put in a k&n filter, Remove or replace the snorkle, put on a hmf dual exhaust,and a EPI performance kit. My question is what should my getting be I have no idea where to start and will it be benefitial to drill some holes in the air box, is there anything else I could do to make it faster.I'am hunting down my cousins DS650 and he's smoking me I will do anything to beat him HELP me. Thanx everyone

 

The pipe requires 142/148 jets so 145/150 should be about right with the K&N and snorkle removed. Holes in the air box are benificial. I would jet up one more size to 148/152 and drill about 10-15 3/8in holes in the lid where there is the most breathing room around the airbox lid. Start with a few holes and work your way up doing plug checks to see the maximum number of holes you want in there. If you do to many you can plug them back up.

 

I just picked up my HMF dual exhaust this evening..... in preperation of that ....

I installed 142 / 145 jets .... and a set of Dial-a-jets. I expect that to be an
equivalent of about 145/150 with the Dial-a-jets wide open.

I also installed a slide gate in the air box lid ( about 1 3/4 square ) with a foam
screen. ( allows me to slide the plastic gate to adjust the amount of extra air )

Like I said... I made the changes awaiting the exhaust ..... but you know what....
it likes the changes even before the muffler change. It is running smooth and
strong through out the power band ..... it feels like I gained a couple of horse
power.

Well... tomorrow we will install the dual exhaust ... and then start tunning the
carbs / air box.