Well, for a start, I don't think the standard ECU on the S4R is remappable. You need to buy a new ECU, which is more expensive than the exhaust system. Without that bit, spending time on a dyno only tells how it performs but doesn't let you make any improvements. Yes, you can change the airfilter, but it won't make much of a difference if at all. So, unless you get the programmable ECU, I wouldn't bother with the dyno. Run it the way it is with the new exhaust until it's run in, then think about tuning it further.
You might want to check with
these guys to see if their new ECU also works on the S4R. Give Neil Spalding at Sigma a ring.
[Edited on 24-5-2004 by Felix]