From all the work i have done on the dyno overall stock pipes seem to be best. I have an MC18 which with stock pipes, swarbrick cans, moded air box and jetted to suit makes 62bhprw

Fitted with the Tyga race pipes, the very most i got was 65bhp. The bike although pretty smooth lost a huge amout of torque below 9,000rpm. it woudl still pull well but no where near as good as the stock pipes.

My frend Bills MC21 SP went the same way,. His motor is lightly ported and made 65bhprw with stock pipes, swarbrick cans, HRC jet kit, no air box.

He went to the exspence of nearly £700 for a set of Gibsons pipes to be made up and lost 1bhp. But he did gain 1000rpm of over rev, He then got a set of Nikons which we wont even talk about their power out put.

So between us we have we have had, 2 sets of tygas, gibsons, nikons, and stocks.

The only ones to make better power where the second set of tygas but at the exspence of a huge about of bottom and midrange for less than 3bhp. So we are both now runnng 60plus with stock pipes and cans. The tygas do look very nice tho :D

I think stock pipes are very very good. Hell that went on for a long time lol