Dyno results hot off the presses!

[GNEPIG]

.. i have posted the vrod dyno sheet in Other Bike Discussion

[mainlylinux]

dyno runs

I love reading about your dyno runs. Is your advancer the kind that is permantely set or can you turn it left or right to set more or less static advance?

Mine was the kind with tamper proof screws, so I removed them and put in normal ones. I then proceeded to advance my timing a bit right at idle. I noticed that I could do a slight power wheelie in first after that - so it must be worth at least a little torque in the low rpm ranges. I'll get mine into the dyno this summer at some point.

Dan

[GNEPIG]

Is your advancer the kind that is permantely set or can you turn it left or right to set more or less static advance?

.. yes, and i have adjusted the timing today to about 5 degrees more than the F mark this afternoon, i will have another dyno test next week.. it would be refreshing to see some other peoples dyno sheets posted for a change. i like this thread but with just my sh!t on here all the time, it is starting to get old

[Shuriken]

I would be posting just as many results if I had access to a dyno.....

[GNEPIG]

.. here i go changing too many things again, apparently i like the challenge
.. i'm not 100% sure, but i think i like this change. i have only put 20 miles on the bike since i put this muffler on, it feels like it has a valve inside or something


.. the numbers look pretty good with this muff on except for that big dip right at 5 grand, i think this is where the valve is working.
. this dip feels different on the street than it looks on paper, i only feel a hesitation between idle and go in first and second gears(between 1 and 3000 rpms), every where else feels real good. i will try to do adjustments and make another dyno pass this week.
.. oh yeah, i love the way this muff sounds, its as quiet as a church mouse(with a mean @ss growl).. you dont have to make it louder to go faster

[Ken Talbot]

So am I reading that bottom line right - looks like the engine is severely leaning out right around 5k, then coming on strong again after that? If that's the case, it must need more fuel for the fuel/air mixture. Is that about where the supply is still being controlled by the position of the needle in the nozzle? At the same time, I wonder if that whole range below 5k is a bit on the lean side....

[GNEPIG]

.. no sir it would be rich below 12.75.. but you are right about the needle position, i will be lowering the needles next
.

[Ken Talbot]

Ah, yes, I see now. It is an air/fuel ratio, not a fuel/air ratio. Very interesting....

[GNEPIG]

.. this run is how it looks with the needles lowered one notch from the middle, not much different than the run before but with less power and torque but a better fuel line. looks like i'm lean on the big end now.. the line in red was the last pass i had made after putting duct tape over 4 of the 10 holes in the bottom of the air box
.. after studying Procampers, TC's and the Ugly black bikes dyno results i'm starting to think that this dip at 4500 rpm is common for bikes with the 4 into 1 exhaust.. the 4 into 1 exhaust makes bigger torque at the high rpms but the 4 into 2 seems to work better in a broader range
.. 4 INTO 1

.. 4 into 1 before lowering needles

.. 4 INTO 2

[LoserShoes]

Just a thought, but what about a resonance in the airbox? The 4-1 might flow more at the midrange, enough to setup the resonance that the 4-2 don't. Any dyno sheets with indivual filters?

Steve

[GNEPIG]

.. TC's bike has individual air filters as does the Ugly black bike, 4500 appears to be a rich spot on the Red bike and a really rich spot on Procamper's bike
..good thought about the air box, LoserShoes

[GNEPIG]

.. Procamper's results, 4 into 1 with air box

.. TC's results, 4 into 1 with individual filters

.. my Ugly bike, 4 into 1 with indi filters

.. very nice numbers for all of these old bikes

[LoserShoes]

Well, it's gotta be that the pipes are probably a bit short. I'd have to dig around in my old Hot Rod articles and see if I have the tech articles on headers with all the formulas. The collector size and shape can make a difference too. Seems I remember someone saying the 4-1 design needed to be tweaked to work right.

Any time the same thing shows up at the same rpm, it relates to lenght or volumne.

Could be that there is just not enough room to do a 4-1 right.

Steve

[LoserShoes]

You might want to take a look at THIS

Steve

[GNEPIG]

You might want to take a look at THIS

.. what this guy has stated about his findings might be the problems we are having with the 4 into 1 headers on our bikes
thanx losershoes

.. the lines are getting straighter, that ditch at 5000 rpms doesnt seem as hard to cross at this state of tune
at this moment the jetting is set at 145 mains, 45 pilots, the needles are set at one notch above the middle, 6- 1/2 inch holes in the air box and i have changed the #2 and 3 emulsion tubes to match the ones on the outside carbs.
.. i am fighting the urge to disect this muffler to see what is inside, i dont want to ruin it. i like the way this muff sounds and my gas mileage is way up!. i was doing a buck 20 on a long stretch of new 301 the other day and spotted the cops sitting on the on the other side of the road about a 1/4 mile away. i started slowing down nice and easy like, they didnt even look up at me, they didnt hear me coming!. its like my bike is in stealth mode, had i been on the ugly bike i would have been busted for sure
.. BTW the way the lines look on the picture is how the bike feels when you ride it