Dyno results thread

[mik_str]

Yeti are the Moti stacks not equal length then like the Dr Honda's. I thought the Dr Honda are an attempted copy of the the Mori's

(:-})

Crl, they are not attempted copies, they are EXACT copies (via digital 3D computer scan and CNC machining) of stacks developed by Bill Finnegan of HPower in Australia. He developed them on a flow bench FWIW. FYI, teh cahp who did the scan (a member of the Supehawk forum) was blown aweay when he saw the complexity of the curves... these are NOT cheap copies... (I know as I spearheaded this project, the CNC files were then sent to Dr HOnda.....)

[AMCQ46]

more good info there mik. now all we need is Roger to fill in the gaps on the pro's and cons of the Mori design vs the HPower versions

[mik_str]

BTW, some nice curves there gents.... Yeti, am green with envy over here......

[Flatline]

Don't know what it means, but it looks bad

I am sure one of you kind gentlemen will tell me what it means......................

In your usual non threatening/unsarcastic/caring/nurturing/non-pisstaking way



Maybe not then!

[lloydie]

Bigger mains and bigger pilots and drop the needle 1 clip .
At a guess !

[tony.mon]

Don't know what it means, but it looks bad

I am sure one of you kind gentlemen will tell me what it means......................

In your usual non threatening/unsarcastic/caring/nurturing/non-pisstaking way



Maybe not then!

The lower bar, first of all, is the air'fuel ratio. Also called the stoichiometric ratio:
the optimum amount or ratio where, assuming that the reaction proceeds to completion:
All of the reagent is consumed,
There is no deficiency of the reagent,
There is no excess of the reagent.

Ideally, as shown with the dotted line, these engines run around 13:1 air to fuel. Where the trace drops below the line, it's richer, (more fuel per part of air, or less air per part of fuel) and vice versa.
However the Storm carbs respond well to being slightly rich low and mid range, but should be about right top end. (over 7000).

The upper graph shows two traces, one horsepower, one torque. The one that looks like the Alps is the horsepower one, the much smoother one is torque.
Let's look at torque first, it's not bad, nice and smooth most of the way but with a little dip around 4000.
This corresponds with where the fuel trace below runs rich, and so you need to set the carbs to lean out at around those revs. Needle position would be a good place to start, if you have clips fitted (i.e. a dynojet or Factory pro kit has been fitted) then move the clip one notch down in both carbs.
If not, a tiny washer underneath each clip will do much the same job.

Finally the mountain-range horsepower curve, I'm hoping that the tech has printed out a "through the gears" run, and the dips correspond to gear changes. Otherwise I'm suspecting a slipping clutch, or slippage on the roller where the bike hasn't been tied down properly (not likely, really).
But he hasn't kept it open to teh rev limiter, at 9200 on Storms, and there may be another 1 or even 2 HP to come, the trace isn't peaking yet when the readout stops.

If that was a real hp trace, it would be dreadful to ride on the road like that, and the fuelling isn't out enough to give that sort of readout. It also doesn't correspond with the torque, which remains smooth.

Hope this helps...

[Flatline]

Certainly does m'lud!

From your comments, it's a good place to start with not a lot needed to "fettle" it

Would that be a correct assumption to take?

[tony.mon]

Yep. Try the needle clips as I suggested then take it back for another run. It's worth a mention, the air filter could also affect mixture, what are you running?
If it's better but not perfect, try 1/2 turn adjustment on the fuel screws, but you don't want to mess up the top end.

Let's see what Carl suggests, he's more the man for this sort of thing as although I've set up carbs a few times I tend to leave it to the dyno operator, as they get to the same place quicker than I do, with less strips and rebuilds of the carbs.

Oh, and ask the dyno op what trace the peaky one was?

[VTRDark]

I'm on you your tail

Drop the needles a clip so pointy end comes out the needle jet (hole) more to richen it up a tad. Or if on standard needles use a 1mm washer. Tweak you fuel mixture screws, carb sync and go from there. When you blip your throttle what's the rev counter do as it comes back to idle. Does hang slightly and drop to idle or drop below slightly and then back up to idle speed. I suspect it hangs and drops as your showing lean on the bottom end. If you have 48 pilots a good starting point for the fuel mixture screw is 2.5 turns out on the rear and 2.1/4 front give or take a 1/4 turn

(:-})

[AMCQ46]

The upper graph shows two traces, one horsepower, one torque. The one that looks like the Alps is the horsepower one, the much smoother one is torque.:

Tony, I think it is the other way round. They have expanded the torque scale so much that it looks all peaks and troughs, but it is the one that peaks first, and we are use to seeing it at less than half that scale. The smooth one which peaks later is the power

[tony.mon]

The upper graph shows two traces, one horsepower, one torque. The one that looks like the Alps is the horsepower one, the much smoother one is torque.:

Tony, I think it is the other way round. They have expanded the torque scale so much that it looks all peaks and troughs, but it is the one that peaks first, and we are use to seeing it at less than half that scale. The smooth one which peaks later is the power

If you look at the caption, the HP reads a peak of 104 odd, and that corresponds to the jagged trace on the LH vertical scale, which normally displays there on dynojet scales.
The smoother trace peaks at the correct point on the RH (torque) scale, and corresponds to the torque max figure given on the caption. I could be wrong, but these seems to match the caption, although it's not easy to read on a laptop.

[AMCQ46]

Never thoughtto look at the caption, so i Just zoomed in and it says peak power is 101.7 which would be smooth line if measured on the LH scale. The peak torque says 64.7 and that matched the jagged one measured on the RH scale.

For me the big give away is that torque always peaks first

[VTRDark]

HP left, Torque right, Torque straight curve, HP the alps. That how I interpret it anyway.

(:-})

[AMCQ46]

HP left, Torque right, Torque straight curve, HP the alps. That how I interpret it anyway.

(:-})

Happy to take bets that the alps is torque.... I have just given it a good study zoomed in....not that I am competitive or anything

[VTRDark]

Well if that's the case then his bike is only putting out just over 64 ponies maybe they are shire ponies and it also contradicts what it says on the top left, max power = 101.74 and Max Torque 64.77. But bizarrely nether of the figures correspond exactly to the graph if you use a rule, Mount Everest peaks just past 104 and the straight curve is 102 maybe your right 102 is closer to 101.74

(:-})