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.

Hi mate,
I think we have had this discussion ad nausea for years, secret pipes this and black science pipes that ,,,DH was in the jelly bean cue early {see foot note } ,Why? ,for one, he has tested his own work and has had to do it with a customers choice of plumbing, then found it wanting, as he had fair idea of how the package should have worked before he even started tuning,,, but we can't knock back work based on something or other on the customers bike, I think we would be getting a little precious about ourselves if that were the case but we do tell customers what is an optimal package for the best outcome ,this is not always listened too and in another context this is rightly so as it’s the customers final say on how his bike looks and sounds as long as he accepts some of his choices could compromise the best outcome.
With engine combinations of decent parts we have a fair idea of what the two peak numbers and curve are going to be within a few hp/ft-lb but we do it factoring in optimal induction and exhaust installations , keep in mind everything that is changed from these favorable items is a minus and will always be a minus its just how much of a minus it will be ,I have yet to see an uneven length curvy /straight /short/long bazooka make more power that staggered duals nor have I seen an air cleaner that looked like a tomb stone behave much better than death to torque/horsepower across the range outcomes. Surprisingly good parts are neither ear smashing loud nor that ugly.
BUT! As I mentioned earlier.
At the end of the day it’s the customer’s wishes about how he wants his bike to look and sound that has to be respected, it’s his choice.
The hard bit for us is explaining where the customers unexpected horsepower loss went too credibly,,,,, down the drain pipe so to speak.
Fuck jelly beans mate, bad for the teeth, you should know better than to offer inducements that are deleterious to health but I will let you buy me a Coopers Ale.

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