Last week I left my 790 with Rottweiler so they could work on their 790 Power Commander tunes. Ultimately, the results were surprising to me and I figure you all would like to hear about it. First, a printout showing all the results. Click to enlarge. Description is on the sheet, but to parse it: clear improvements from tuning. The blue line is stock. Green line is Rottweiler's bike with Arrow decat and Arrow open muffler. Red line is Rottweiler's bike with the full stock exhaust, but tuned with the power commander V. Orange is my bike with the sharon exhaust. Before anyone asks - my bike made the same power with the stock exhaust with only the tune as Rottweiler's bike, so they're very closely matched motorcycles. Because of this, we believe these graphs are comparable even though we never put the Sharon exhaust on the Rottweiler bike. Some interesting things here. First: the highest peak power was achieved with the stock exhaust and a tune - the decat, even tuned, doesn't make more peak power than stock. Not shown is an untuned decat, which also did not make more power than the blue stock line shown above. The Sharon exhaust doesn't make as much power as the stock exhaust, OR the Arrow decat + muffler. Definitely wasn't thrilled to find this out, but it's still a great looking exhaust that is lightweight. At least that's my consolation. Also MUCH cheaper than other Decat + open muffler options, though the fit isn't as good. I'll keep it, but if it gets damaged in a crash, I'll likely just reinstall the cat and do a slip-on... and gain some power back. Let's look closer at stock VS tune only. Small gains below 4k, but very significant gains starting at 4500rpm. Now, stock VS Decat, open muffler, and tune: While the decat did not make more peak power, it does have a considerably fatter midrange. I would say that fatter midrange isn't enough to be worth decatting on its own, but it's a nice perk if you choose to decat. At the end of the day, if you're decatting for power, it's not worth it. Yes, slightly fatter midrange, but only slightly, and no top end gain. If you're decatting to save weight and reduce heat, without the expectation of greater output, it's probably the cheapest and easiest way to shave a few pounds off the bike. Some notes on the stock tune. Several of you have noted that the bike feels like it really comes along at 6k rpm. Here's why: View attachment 1978416 The stock tune is extremely lean up til that point. That's 14.5:1 AFR at full load/full throttle - crazy lean. It finally gets down to reasonable AFRs at 6k RPM, which is why the bike suddenly feels so much healthier. Finally, riding impressions. Spent all day on the bike on Saturday. I had previously spent a day on the bike with the Sharon and no tune. Though my dyno result post-tune with the Sharon exhaust was a bit disappointing, the bike felt completely different. MUCH smoother fueling from low RPMS. The bike pulls very cleanly even at large throttle openings from 2k rpm, none of the feeling of flaming out like stock. Power delivery is smoother and crisper, and high RPM power is noticeably better. Transitions on/off throttle were also smoother. Unfortunately that only lasted a couple of hours, because we accidentally left the O2 sensors plugged in which resulted in the OEM ECU taking over again and reverting to the stock tune. Just have to get in there and unplug them and I'll be back to smooth, tuned glory. Shout-out to Chris at Rottweiler. Awesome shop, great guys. Looking forward to buying more stuff from them.