The link below clearly shows asymmetric engine exhausts on McLaren, with right hand side exhaust having a larger diameter than the left one.http://en.f1-live.com/f1/en/photos/popu ... po_133.jpg
I am trying to understand the reason why they would have this, unless they are mixing some other flow in on the right side exhaust. That could still change the pressure on the engine exhaust which in turn be a difference on the power output of left to right. That should not register as a vibration at 18k rpm, but some additional torque on the engine.
Does anyone have other ideas?