DYNO Result

[Killerwhale]

Most dynos have the facility to give a crank DIN output - I guess yours is crank power...............still a good result

Yep, as he showed standard at 76-ish wich is crank for a standard bike.

[Redog1]

Most dynos have the facility to give a crank DIN output - I guess yours is crank power...............still a good result

Yep, as he showed standard at 76-ish wich is crank for a standard bike.

Spoke to the mechanic today, and he said he didn't have any conversion values to calculate crank HP.

But, does it really matter. I only put it on the rolling road to check I wasn't running too lean. Its not so all's good.

The 100hp is just a bit of fun. It will seriously upset my German friend who owns 2 TRXs and takes his bike (and himself) far too seriously.

Cheers

[HansJ]

I think you need to talk to the mechanic again, he must have missed something...

A way of measuring if an engine has a decent output is specific torque, i.e. torque per cylinder volume. A rule of thumb is if the specific torque in Nm is over 0.1 per cc, it breathes well (suction engines). As an example, i looked at the Duc 848, with same cylinder volume. It produces 140 BHP @10500 and a torque of 72.3 lb/ft @9750 rpm(which equals to 98 Nm, well over the rule of thumb's 85, an extremely good figure!), and these figures are (probably?) at the crank. The figures your mechanic gave indicates your engine has a torque of 106 Nm. See why people are sceptical?

But as you said, in the end of the day, it doesn't matter. It only shows dyno figures will always differ. I do dyno runs since i want to see the effects of changes, and checking the mixture, i.e. optimise my engine.

But i agree, over the ton is something to stick in yor friend's face

[Redog1]

I understand the concept of specific torque, but, whatever you measure on the dyno is crank output minus mechanical loss, SO this will be slightly different for each different machine. Am I missing something?
HP (KW) effectively Work, is a function of turning force (torque) and time. So the machine can only measure the turning force from the tire and then use the time measured to make the calculations. The mechanical loss from the crank to the road is factor of the gearbox, chain etc.

Are we in furious agreement? Or am missing your argument?

Cheers

[Redog1]

Hans, I omitted to mention I totally agree with the skeptics.
I think 90hp is more plausible.
I was just having fun with the outrageous number.
Using a sympathetic dyno is far cheaper than hotting up the engine.

Cheers

[HansJ]

I am not furious, and i am unsure if we agree or not

You're right in that the mechanical loss differs from bike to bike. I've been showed how a final lube of the chain gave my bike another 2 Hps on the dyno. And you're right about torque. I just took the Duc as an example of a highly tuned modern engine to show that the Dyno figures you got from the mech probably are exaggerated. Your figures seemed a bit too much "off" to be explained by having much less mechanical loss, or much better breathing than the latest Duc 848.

I have the feeling i might be considered as a besserwisser and generally rude, please don't take any offense, it is not at all meant that way. I am just interested in engines and tuning and like to discuss!

[HansJ]

Hans, I omitted to mention I totally agree with the skeptics.
I think 90hp is more plausible.
I was just having fun with the outrageous number.
Using a sympathetic dyno is far cheaper than hotting up the engine.

Cheers

OK, i agree on all of that, unless your furious, we're happily agreeing then

[dandywarhol]

Interesting post and knowledgable conversations - and the reason for the Duc's high power output is because it's producing it's power at much higher revs than the Yam. Work done (torque) in a shorter time = higher power output.

[HansJ]

Interesting post and knowledgable conversations - and the reason for the Duc's high power output is because it's producing it's power at much higher revs than the Yam. Work done (torque) in a shorter time = higher power output.

Partly yes, definitely, but the latest model has a much higher specific torque as well.
Previous duc had a specific torque approximately around the 0.1/cc, very close the 85 Nm, and still produced 117 BHP, could we get the TRX to rev as high we would see similar figures.

117 bhp (87 kW) @ 10,010 rpm[2]
63.1 lb·ft (85.6 N·m) @ 8325 rpm[2]

But the latest version has a higher specific torque, which is why it produces much more HPs at a slightly higher rpm (500 more).

[dandywarhol]

I think we're singing from the same hymn sheet here - if the torque is done in a shorter time (eg higher revs) then the power will go up. The fact that Duc have got near perfect combustion to produce their torque figures also raises the power output.

Anyone got a turbocharged TRX engine - some Greek guy did it to his TDM900................

http://www.youtube.com/watch?v=iI8iPfl2a_Q

[Mincehead]

Here`s another one:

http://www.youtube.com/watch?v=ouAZzqc_ ... re=related

Nice how she spins up the rear no trouble and the whistle would soon become addictive!
Mind, that one`s a bit more `heath robinson`by the look of it and I sure hope they are going to fit a filter for the turbo or that impeller will soon be grit blasted to destruction.
Some kind of crazy MF test riding it in that street, with no seat on it either.

[M.V.]

I think we're singing from the same hymn sheet here - if the torque is done in a shorter time (eg higher revs) then the power will go up. The fact that Duc have got near perfect combustion to produce their torque figures also raises the power output.

Anyone got a turbocharged TRX engine - some Greek guy did it to his TDM900................

http://www.youtube.com/watch?v=iI8iPfl2a_Q

That's pretty cool, but there's no way that could be putting out 210hp right?

[Mincehead]

Not VERY likey but possible, turbo boost set to `destructive` might give it, for a short period of time!
Remember there`s been plenty of FAST small capacity blown bikes, here`s possibly the most famous:

http://www.trakbytes.co.uk/mouse.html

Brian Chapman was a true garden shed drag racer and 125 bhp from a blown Vincent Comet is not to be sniffed at!
Ok he was running dope (nitromethane) but it was the first 500cc motorcycle to break the 8 second standing quarter time in the world.I saw and HEARD (owwch) it race a few times as a youngster, Blackbushe was one of my old mans favourite haunts, he always said, " I like coming here lad, it drowns your mother out".
Brian used to run against multi engined Japanese stuff and beat most of them too, some machine.

[Killerwhale]

Not VERY likey but possible, turbo boost set to `destructive` might give it, for a short period of time!
Remember there`s been plenty of FAST small capacity blown bikes, here`s possibly the most famous:

http://www.trakbytes.co.uk/mouse.html

Brian Chapman was a true garden shed drag racer and 125 bhp from a blown Vincent Comet is not to be sniffed at!
Ok he was running dope (nitromethane) but it was the first 500cc motorcycle to break the 8 second standing quarter time in the world.I saw and HEARD (owwch) it race a few times as a youngster, Blackbushe was one of my old mans favourite haunts, he always said, " I like coming here lad, it drowns your mother out".
Brian used to run against multi engined Japanese stuff and beat most of them too, some machine.

If it´s the same...that Greek dude has both turbo AND nitro!

[trixy7]

I had mine done Dec 09 and it was done on dynojet machine and figures are 71.86 hp ATW only mods are K&N, D&D pipes and carbs jetted 65ks on the clock, dont know how this compares but it sounds good to me without any fibs?