OK, you're wrong, the 800, 1000 & s4r are 40mm stock from front to back period. they start as 40mm and are 40mm to the mufflers, (so you can use the marving with stock mufflers or slip-ons)
Model #1 |#2 |#3 | #4 #5 |#6 |#7
S2R 1k | 40mm | NA | NA | 40mm | 40mm | 40mm | 40mm
S2R 800 | 40mm | 40mm | 40mm | 40mm | 40mm | 40mm | 40mm
S4R | 40mm | 40mm | 40mm | 40mm | 40mm | 40mm | 40mm
the marving is 40mm it replaces the stock pipe & udder, the slip-ons are 40mm at the udder and 50 at the muffler, so this would be with slip-on's
Model | #1 |#2 |#3 | #4 #5 |#6 #7
S2R 1k | 40mm | NA | NA | 40mm | 40mm | 50mm | 50mm
S2R 800 | 40mm | 40mm | 40mm | 40mm | 40mm | 50mm | 50mm
S4R 40mm | 40mm | 40mm 40mm | 40mm | 50mm | 50mm
then this would be with full arrow or termi's ( I don't have termi's but I think they use the stck fron section of the collector as well)
Model | #1 |#2 |#3 | #4 | #5 |#6 |#7
S2R 1k | 50mm | NA | NA | 50mm | 50mm | 50mm | 50mm
S2R 800 | 40mm | 50mm | 50mm | 50mm | 50mm | 50mm | 50mm
S4R | 40mm | 50mm | 50mm | 50mm | 50mm | 50mm | 50mm
after this i'm not sure what else to tell you....
I started with the marving & stock mufflers...(too quiet)
then got arrows (titanium) with baffles (still too quiet)
took out the baffles, good sound, loud!
them got CF arrow cans....louder yet...deeper sound
no pic yet...sorry
next should be Arrow collectors (50mm) front to back....
close to this....
Mike