I would guess that the straight pipe might would be better, but leaner, since there's no back pressure.
The best would be an expansion pipe, it bounces the unburnt gases in the exhaust back into the cylinder, kind of supercharging the engine, but from the exhaust, not the intake.
sickbikeparts.com sells these, and I think spookytooth does. Do a search on them.
The best would be an expansion pipe, it bounces the unburnt gases in the exhaust back into the cylinder, kind of supercharging the engine, but from the exhaust, not the intake.
sickbikeparts.com sells these, and I think spookytooth does. Do a search on them.