My AR on the dyno

[admin]

Spec is: Full DEP system, 150 main jet, Mugen CDI - oh and a couple of CRM250.COM stickers

[Active Rascal]

That's a VERY good effort. Mine is what I would call very tuned, and also has had a complete rebuild, and only reached 29BHP!!

[twistednuts]

On the graph, can you show the line without stickers?

Need some new stix, are they still available?

[admin]

Nah, most took an age to go, then i put them somewhere safe - only to stay somewhere safe sorry.
i was curious to know how the mixture was, i am at cadwell in 2 weeks on track so wanted to be sure it was not too lean - looking at the graph that's about as perfect as you can get mixture wise.

[fallenmikethebike]

Sweet.
Mike

[knackeredMk1]

As always with dynos there is some discrepancy between each and I've seen a few CRM traces . The AR is quite difficult to tune from standard in comparison with the other Mks and if original is generally down on the Mk3 for top end but with slightly more low down torque. Some would say original power is about the same as a Mk2 and a little more than a Mk1.

A Japanese magazine made a Mk2 enduro racer. In changing the engine they put on a full Mugen exhaust and ECU, gave the porting a thorough working over, skimmed the head, removed the balancer shaft and oil pump and made the air box breath better and they only got a 5 bhp gain.

36 bhp is very much at the top end of what would be expected. 29 bhp is generally what an AR comes with as standard. Gaining 7 bhp is very difficult to do.

Pipe and silencer generally give ~1.5 bhp to all models and are good value given that the original silencers are impossible to clean out and the expansion chambers are difficult to clean and heavy to boot.

The Mugen ECU does very little except remove some of the 'restrictions' in low gears that the original has to increase drive rather than wheel spin at low speeds. The Mugen head does more to the power by increasing compression and giving much more low end hit and a better overall burn.

[admin]

This particular dyno i have had quite a few of my bikes run on over the years.

It gives i feel a real world figure (which while of course can be exagerated by the operator), Chris has always shows results as he sees them.

My RC30 made 99 at the wheel in 2005 on this dyno, yet when run in the midlands (Projex) in 2006 on a different dynopro dyno showed 104 at the wheel !!!, and yet when run back on the same dyno as used in 2005 later in 2011 it made 98 at the wheel. those figures are typical with a RC30 showing the miles mine does under its belt.
Again my UK spec NC30 had issues, and on the dyno it made a good peak figure, but it was crap to ride. We found all sorts of issues (mainly head castings and cam timing being out - cam gears were pressed on to the cams in the wrong place, so while timing was right, cam timing was way off) and my UK spec NC30 makes a real 57 at the wheel with a lovely flat linear curve.
My RVF #1 makes 58 which is quite low on paper but kicks some ass compared to some RVF#s of similar spec showing an indicated 65+ on different dyno's
Then of course my NSR250SP MC28, making a low 52 bhp when i was expecting more like 56+ after all the mods.

So to see just over 35 from my AR was nice, however it still pops and farts low down through town which really pisses me off, its fine when flat out, not so great other times.
the curve does look pretty good through which is nice to see.

I wish i took the OE CDI to do a back to back run now.

[knackeredMk1]

Aha I forgot - You ran with SM wheels on . That is an instant gain of about 3 bhp over knobblies. Furthermore did you run with an HD chain or 'O or X' ring . O and X ring chains cause more drag but that doesn't matter when off road as their ability to keep lubricated far outweighs the loss.

Copious apologies - 35bhp is quite achievable under these conditions

[admin]

It is o-ring
And it was strapped down onto the dyno well - with 24psi in the tyres lol.