This is a good dyno graph showing a comparison between two different exhaust systems. Bike EXACTLY the same, each system was tuned by me and this shows what is very difficult to tell customers who ask the question. (usually AFTER they have bought the exhaust) Hope I can get the photo up...

Ah, it worked. Note the great increase in the lower/mid range as well as the top end power. Now who gets the jelly bean for which was the best pipe?  Bike was a 103 with 52mm Throttle body, 10.6 comp, 625 S&S cams and Hoodys heads. As a bonus the bike was quieter when finished as well....

Don't know what brand of pipe but i will put my money on a 2:1 with stepped header pipe because of the increase at low RPM

Oh they're most definitely V&H Short Shots !

the Red Jelly bean please.
Maybe has a more efficient and effective perforated baffle in lieu of the louvered type baffle.
either pipe could be any brand and type

Any more takers?? The bike is a 2010 Dyna. Daily rider. BTW NOT a 2:1. If it was a 2:1 the low rpm dip would still be there but lower down and not as pronounced.Dyoharley found that above.. :-)  And re lurker 501, the pipes I think you allude to I don't find hard to tune, but annoying. It just seems like a waste of time trying to  tune for power, with something one knows is not good for power.

Stock head pipes with slip ons or supertrap.

The proper curve is stock headers with balance pipe and S&S taper turbo mufflers and the original (blue) curve is V&H staggering big shots. The V&H pipes had already been improved by the baffles mentioned above. The main reason I put this up was to illustrate how a good combo of parts can be knobbled by one badly chosen part. This is not a new thing, poor choice of exhausts for the bikes usage accounts for many a long face after dyno work. ( and air filters to for that matter) Dyno harley makes a similar point, looks don't make them run well.

So what are the best tried and tested air cleaners and how much of a difference does a good air cleaner make compared to a bad one?

Did I miss something , which was the better brand / style of pipe to use ... the suspense is killing me , Lol .

Sorry Lushy , I missed reading your 1.35 pm post ... may I be forgiven , Lol .

If you are buying looks when you go for a pipe, then thats fine. Very often the look will cost you power. I have no problem with any of that until some one says ,"I really want all the power I can get, why doesn't my bike do 120hp like the engine builder said?" There is almost always no free lunch, and noise is not power. My main reason for this post was to enable folk to make an informed decision before spending their money. Have fun guys.

2-1 rules on my ride after 6 year trial of pipes and bungs for closed loop vtuning

HD Owner zeroed out again