Hos
#1 Simpson should be able to sew you some arm restraints for a nominal charge. We liked them because like Mittens they tend to get misplaced right before it is time to go out.
#2 I am a Muffologist by trade. We introduced left side exit exhaust in Mini Sprints back in 1992. The reason I had a head strong driver that wanted it to look like a Midget. We have tried about every exhaust configuration possible on the Mini's up to and including 4 single out with expansion chambers (we did get a kick in the butt at the end of the straight at the old Lawrenceburg) but couldn't use it). We have actually filled the primaries with liquid to cc them out so that would be perfectly equal. After doing all this research what we determined is Exhaust is pretty DUMB (get it close enough for government work) and go with it. I have a friend with a Dyno, he is that same driver I was talking about. He has claimed some success on the Dyno with HP numbers and primary lengths, BUT tracks do not perform like Dyno's. My next exhaust was going to be 2 out each side since everybody has seemed to fall in love with our left side Idea. I would probably bring them out 360 degrees out>>> that should help scavenging and make a weird sound. Be advised that if you are any good at set up and driving pretty soon everybody will be doing it.
PS. Ask any body that has listened to our old Kaw ZX10 what it sounded like>>>>and for that matter how it ran.