Dyno graph reading

[darrsi]

[size=1.35em]Here's a graph of a Dyno reading for my 2000 SP 600.(2 years ago)[/size]
[size=1.35em]The lower line was from when the bike had a hesitation/stutter issue on harder acceleration/overtaking, so i had the bike in for investigation which ended up as a carb overhaul, but the problem actually turned out to be number 2 carb inlet rubber that had folded in on itself on reassembly after having the cam chain replaced at another bike shop.[/size]
[size=1.35em]Even though i took the bike back several times to the shop, 3 of them rode it and refused to acknowledge that there was a problem, which as you can imagine made my blood boil a bit, but what could i do?[/size]
[size=1.35em]So i took it to PDQ and after taking the carbs off he noticed the offending inlet rubber that had been folded in half by about 10mm and then tightened up, so it was just letting too much air in when a bit of power was needed.[/size]
[size=1.35em]Obviously the upper line on the graph is when everything was sorted.[/size]
[size=1.35em]That turned out to be a very expensive month for me [/size] :'( 


[size=1.35em]On this graph i had a Quill unbaffled race can on at the time, with a standard paper air filter, and i have an unknown make of replacement stainless downpipes, although they're probably Delkevic.[/size]
[size=1.35em]I now have an SP Engineering Moto GP end can, which is shorter, and i leave it baffled due to noise and unwanted police attention, and a K&N air filter fitted, and after having the bike Dyno'd again last week it had dropped by about 0.5bhp, which i think is expected anyway due to wear and tear, and age.(the bike, not me [/size] :b )

[scottyboy2203]

Thanks Darrsi that is really interesting for a sad git (engineer) like me! So the standard filter and unbaffled can was better? Sounds sensible to me. Can't believe how flat that torque curve is above 8K, lovely engine!

[darrsi]

The Quill was just a straight through can, it never had a baffle.

The Moto GP exhaust is just a bit too noisy to chance removing the baffle 'cos i just know i'll get pulled for it.
It's also got British Standard markings on it so is fully legal with the baffle in.

[red98]

thanks for sharing that DARRSI very interesting .........if all else fails with my stuttering fzs600 i might give them a call ,not far from me as iam in high wycombe.......are you local ?

[darrsi]

Harrow

[red98]

Harrow

do you get up to the ace much 

[Paul]

Some stainless steel headers don't offer enough back pressure, Motad for instance; and you need to sleeve them down at the collector point.

The Motad collector pipe measures 1364sqm whereas the original collector has an open area of 962sqm (based on a 2mm wall thickness) at its pinch point.

You can see where the original back pressure adjustment (pinch point) was made point on the standard header pipes collector point.

[darrsi]

You're not gonna believe this, but i worked in the road behind the Ace Cafe for 4 years, before relocating to Greenford next to the A40 for the next 14 years, and i've still never been there!!! :rolleyes

[red98]

[size=1.35em]You're not gonna believe this, but i worked in the road behind the Ace Cafe for 4 years, before relocating to Greenford next to the A40 for the next 14 years, and i've still never been there!!! [/size] :rolleyes

great meeting place    iam up there on sunday with a few friends (if all goes well) hornet day :\  i know what your thinking :rolleyes :rolleyes :rolleyes :rolleyes    mates got one,probs have to wait for him to catch up a few times and also several stops for fuel  :rollin :rollin :rollin :rollin [size=78%] [/size]

[wraith600]

hi gys this is the last dyno one i had done / also live 5 min from the ace and never go there as normaly just meet dick heads who aint interested in some one riding a 98  even if it it heavy  modded like mine 

[Jamieg285]

Thanks for the graphs guys.  Very interesting, and not at all what I was expecting.


They really have produced a great engine there.

[darrsi]

@wraith600, what have you had done to keep your BHP so high on a 14yr old bike?  :rolleyes

[wraith600]

hardley use it + 30 years of modding  bikes

[thom_1991]

Don't you have a Micron race system. Anything else? Needles/jets fiddled with?

@ darrsi did you not get an AFr trace?

[darrsi]

If i knew what that was i'd let you know?  :rolleyes

[thom_1991]

Lol sorry the air fuel ratio trace. Showing you whether its rich or lean at whatever point in the rev range.

[darrsi]

No then, just the torque and bhp as in what's showing on the graph  :lol
I'm still interested as to how 'wraith600' graph has 152mph written on it, on a bike that's advertised to do 140mph max from brand new, and only peaking at 10,300rpm?  :rolleyes

[thom_1991]

Theoretical speed as its only spinning up the dyno drum in top gear. Also he has a rare as rocking horse Micron race system (wish i could find one) and some other bits if i remember rightly. You got me stumped on the rev limit though. Wraith?

[wraith600]

revs out at 11500 carbs have been dynojeted with a k&n filter and a cut down performance racing parts  can with the mentioned micron pipework and the addition of a g pack 0/40 oil and a heavy duty clutch springs with kevlar plates and thats about it at the moment    doing a HID head light mod with 2 complete light units now but having motavatonal issues basicley  cant be assed when i get it done  :lol  more exhaust mods and some airbox / intake mods and maybe a gasflow

[darrsi]

That lot could be responsible then........nicely done  :lol