DYNOMy laptop crashed so I don't have access to post what I really think is useful (overlaying 2 different setups to show the difference).
The software used to show the dyno is the old school version of Winpep but none the less you get the idea.
I had originally dyno'd it using a 38AS. Arlan and I decided to "play around" and taper bored the carb out to a 41.5. Jetted with a CEJ needle 3rd clip, 52 pilot and a 180 main. We saw the power shift ~250-300rpm scooping out the bottom and mid but produced 2 HP extra on the top. We all like big numbers but I assure you that was ABSOLUTELY the wrong way to go. In fact I just switched back to a 38AS. Nature of the beast my friends, the larger the carb you lose down low and gain up top. 38AS is magic - leave it alone. Arlan was doing R&D on his 350G pipe. The
one pictured is the first release candidate. Was really cool watching my bike build more and more power as Arlan worked his magic on it. It was about a weeks time every night getting emails with dyno results. One of my fondest memories for sure.
Bottom line, IMHO the HUGE benefit of having a builder like Arlan that also makes pipes is the combination is killer. Unlike most companies who talk a big game, he is certainly one of the few that can backup his claims with dyno's. Yes, some people (and a few companies) will say dyno's are a waste or can be cheated. Well, some what true - that part about falsifying info anyway. For instance doing a dyno pull while the motor is cold can get ya a couple ponies. But I will say after using Winpep myself, there are no "cheats" within the software. Let's put that rumor to rest right now.
And another thing I'd like to mention, where I live (Portland Or.) we jet our bikes for 0-500. So you compare my bike to a bike dyno'd in (let's say) Idaho - there's a HUMONGOUS difference and not for the better. The altitude difference is a power killer. Less air + less gas ='s less HP.