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Dyno results from Saturday, comments and opinions please

Posted: Tue Apr 03, 2012 2:32 pm
by 28hodge
Image

Ok so got the bike Dyno'd on sat morning, and above are the results, speaking to the lad that dyno'd it, a minitwin racer, he reckoned to raise the needles one clip (i do have adjustable needles that have a shim of unknown thickness under them) and then increase the mains as it is lean on WOT, and as it stands at the minute it allows for no run on beyond the 12k range.

The bike made 62.8 but then he corrected it and the figure shown is a corrected figure, not exactly sure what the correction takes account for though, anybody able to explain?

The dyno guy said that he hasnt seen a NC30 make 60 on his dyno before but he also said he hadnt dyno'd many so it dosent say that much but when i said i was hoping for around 60 out of it he said that he didnt think it would make 60 so im chuffed to bits that it has.

Bike spec is as follows,

Full Micron Race system 4 into 1
122.5R
120F
The needles were on the 3rd clip outta 5 possible positions (since the dyno i have moved these to the 4th clip to richen up the 7k-9k range
Standard float heights
standard pilot jets
pilot 2.25 out
Standard airbox system running snorkel and honda airfilter
airbox base is completely unmodded
no rubber flap
All comments more than welcome

Re: Dyno results from Saturday, comments and opinions pleas

Posted: Tue Apr 03, 2012 2:35 pm
by CMSMJ1
cannot see the pictures very well ;-)

Re: Dyno results from Saturday, comments and opinions pleas

Posted: Tue Apr 03, 2012 2:43 pm
by 28hodge
yeah cant get into my photobucket as im at work, tweaked it now so should be better.

Re: Dyno results from Saturday, comments and opinions pleas

Posted: Tue Apr 03, 2012 3:11 pm
by scooble
would say it looks slightly lean, although could do with making slightly richer from about 8k.
As this is WOT, I suspect that 1 size bigger on the mains should about get you there.
Ideally, your looking for around 12.5:1 on full load with about 0.5% O2, yours looks to be around 13:1 to 14:1

Re: Dyno results from Saturday, comments and opinions pleas

Posted: Tue Apr 03, 2012 6:52 pm
by 28hodge
Do you think I should leave the needles as they are then and simply increase the mains, thinking putting the 122.5 from the rears into the front and getting some 124's for the rears?

Read a couple posts last night which basically says all jets are not equal, basically a 122 dj jet is actually bigger than a 122 keihen jet due to its better flow characteristics. Unsure what the current jets are although I'm sure the 2 122.5 jets had RO on them so I'm hoping some 124ro jets will be ok?!!?

Re: Dyno results from Saturday, comments and opinions pleas

Posted: Tue Apr 03, 2012 7:13 pm
by Kurlon
Correction Factor - Differences in ambient air temp, humidity and air pressure all vary the final output of a motor. There are a few different schemas for accounting for those variations, the most common one being the SAE formula which adjusts the reading to match what you would have gotten under standardized test conditions.

http://wahiduddin.net/calc/calc_cf.htm covers the topic really well, including a lil calc so you can play with the numbers yourself.

On main jet numbering, the big difference stems from how Mikuni and Keihin size their jets.

Keihin goes the simple route. The jet size number is a direct metric measurement of the diameter of the hole. Mikuni hex head mains state a made up 'flow unit' for their sizes. As a result, going up 5 points on a Keihin is different than going up 5 points on a Mikuni, because it takes far less than twice the diameter to flow twice as much fluid.

Dynojet to be cute uses their own schema. http://www.triumphtalk.com/showthread.p ... -Jet-Sizes has a conversion chart. I have to confirm this but Mikuni round mains may be like Keihins and specify diameter rather than flow units...

Net result, examine your jets to see what they're stamped with before swapping.

Re: Dyno results from Saturday, comments and opinions pleas

Posted: Tue Apr 03, 2012 7:21 pm
by scooble
I heard that too wrt jets, best to stick the same type really to ensure consistency.
As your graph is WOT, can't really say whats happening with the needles, but your Full Load power figures look good and as it seems to be running a little lean at the top show that its breathing pretty good