Another point to consider while I think of it, when altering you bikes plumbing regarding the exhaust is that a bigger diameter freer flowing pipe can effect the 'Engine braking'

I held back from a complete Yoshi on a DRZ as I found out from somewhere that the bend in the Header pipe was there to assist in engine braking which is useful in off road situations as opposed to stomping on the brake & locking up the rear wheel. The Yoshi header pipe had less bends in it which was good for acceleration, which suits the SM, but not so the E model DRZ.