At the risk of providing my opinion, not dyno sheet, I will offer this simple observation. I started out stock. Then the Jardines, with a Power Commander set up by Jardine on the dyno at Jardine. Then back to stock while Jardine made the jigs for the header system. Then the full Jardine system without the Power Commander, which runs strong, but decel pops like a mother. Then the PC3 was re-installed. Then I removed the secondaries and put on three simple wire screens over the throttle bodies. It ran better. Then I put in the resistor, but with a double throw switch so I could try it both ways. Fooled into 4'th it had more power still. I replaced the secondary plates. It felt almost no different in power with the 4'th gear switch on. I lost all ability to idle and it appears something failed in the Power Commander, so I removed it. The bike returned to OK idle, but the decel pop returned as would be expected. Then I put in the Tune Boy with Hombre's tune which is close to mine, but too rich. The difference is phenomenal. I am removing the switch. When you look at the maps of ignition advance and throttle postition and fuel, they all have a dip, part way up. I believe this is used to reduce the sound (and power) at the speed/RPM/throttle position that the government tests the muffler system at. I notice that while the dip remains, it is almost gone on Hombres tune.