Harry
I'm confused about the pulling muffler off - how does that help - I mean the backpressure created by the exhaust system is a key part of performance and general state of tune - how does pulling the mufflers aid the tuning process.
Also - I've got a 2 into 1 exhaust system (Big Radius)
On the bright side - I do have their dyno sheet so I will have some basis of comparison (even though they could fudge thru overinflating the tires or pulling the air cleaner cover (although I have the SE backplate which allows a huge amount of air to reach the filter so I don't know if pulling the outer cover would help much?)
A lot of times, they'll pull the entire filter off, leaving nothing but the backplate. It WILL give you about a 5% gain in numbers...3-5 on both sides. IMO, and that of a very experienced tuner used by me and a couple of others in the area, the SE backplate, with the stock 0800 K&N is marginal on amount of air flow allowed into the TB on a 103 or larger engine. With a 2/1, pulling the muff allows them to get the sniffer into each header. With True Duals, they can stick the sniffer far enough in there to get a good reading, particularly with an open muffler, like the Rinehart's. On a PCIIIUSB, this is called an advanced tune, in that each cylinder is tuned independently. Setting the A/F ratio, etc is not dependent on the muffler being on the bike. Doing a pull to see what the numbers are is where the presence of the muffler comes into play. I'm not a big believer in Dyno numbers, all other things being equal, but I am a big believer in getting a good tune regarding A/F and Timing to achieve decent fuel economy on cruise throttle positions, and not being overly rich at WOT. This will make the bike a better driver. To tweak every last HP or TQ out of the motor is not as important to me as how the bike feels in real world riding.
Harry, feel free to correct me if I have misstated any of this....