Dyno

ojenson · Post by **ojenson** » Wed Oct 25, 2006 11:31 pm

I just got both of my 750 paso on the dyno today. My blue paso with dual dellortos got 58hp and the torque was 95. my limited with the stock weber got 55hp and in the low 90s in torque. Does this sound right??

Post by **jcslocum** » Thu Oct 26, 2006 12:16 am

Not really. The HP seems a little low and the torque is high. Did they run a chart for you?? Can you post it here?

2 Paso's, Damn.....

Finnpaso · Post by **Finnpaso** » Thu Oct 26, 2006 12:26 pm

Those charts tell much more, than only numbers, so it would be nice to see Pasos charts here... especially that torque chart! 90Nm feels very high from 750 engine.

MTS and my ST4S (both with new better ECU and open exhausts) gives 100Nm and much more bigger engine with 4 valves(ST4S)....

persempre907 · Post by **persempre907** » Thu Oct 26, 2006 12:51 pm

jcslocum wrote:Not really. The HP seems a little low and the torque is high. Did they run a chart for you?? Can you post it here?

2 Paso's, Damn.....

Yes, the torque seems to me very hight, but the power is right.
The omologation chart was lying...
For the 907 has been declared 92 hp.... It don't have more than 75....
Ciao

ojenson · Post by **ojenson** » Thu Oct 26, 2006 9:37 pm

Isnt the factory hp measured from the crank? The dyno i went to measured the hp from the rear wheel.

Post by **jcslocum** » Fri Oct 27, 2006 12:03 am

Lets clear some things up first. When I saw the HP figure I assumed you were quoting a FOOT POUND figure for torque not Newton Meters Nm. Your in the USA so I'm figuring it was Ft. Lb. 90 is too high for a 750 to make.

HP is just a calculation from tourqe so the original chart would be very helpful

Finnpaso · Post by **Finnpaso** » Fri Oct 27, 2006 7:50 pm

"HP is just a calculation from tourqe"

I think, U are wrong now.... I dynoed my ST4S just some month ago and those HP curve(chart) and TORQUE curve(chart) are totally different !!!! I cant imagine, HOW U can "ONLY COUNT" that???? If U have very good explanation, surely then i can accept Your taughts....

Anyway to me, "torque" and "hp" are totally different things....

Anyway there can be misunderstood with metric and US units with those numbers...

DesmoDog · Post by **DesmoDog** » Fri Oct 27, 2006 8:35 pm

Horsepower (using English units) is defined as (Torque * rpm)/5252. There isn't any dyno in the world that I know of that actually measures horsepower, it's derived from the torque curve. Unless it's an inertia dyno, but even then horsepower is derived.

Torque is a force. HP is simply the rate at which that force can be applied. Switching to metric units only changes the denominator of the equation. If you google "equation for HP" you will probably come up with the derivation of the formula that will lead you through the steps to get to 5252.

Sidenote: On any US dyno curve that measures HP and ft*lb torque, the curves will cross at 5252rpm. Many dyno charts will show torque and HP on different scales so it doesn't look like they cross there, but they do, by definition. If not, someone is playing games with one of the curves.

Finnpaso · Post by **Finnpaso** » Fri Oct 27, 2006 8:49 pm

"Unless it's an inertia dyno, but even then horsepower is derived" ??? My ST4S was in INERTIA dyno. But i must look more those my dyno charts... very intresting, but surely my "english" is quite bad also... :laugh:

DesmoDog · Post by **DesmoDog** » Sat Oct 28, 2006 3:01 am

Most shops are probably using inertia dynos these days, they're cheaper than brake dynos.

Inertia dynos use a known mass (the roller) and measure how fast the bike accelerates it up to speed. From this they can figure out the power needed to spin the roller up in that amount of time. It's been too long for me to remember the exact formula - any work I've done has been with brake dynos. OEMs don't use inertia dynos for development, brake dynos are more uselful. (FWIW - the dyno we just installed at work cost over $1million if you include all the stuff needed to run it...)

But the point still remains, HP is a function of torque and RPM, no matter what type of dyno you're using. There's no magic to it and you can't change HP without changing torque.

FWIW - If I'm doing the math right, 90 newton meters is about 66 ft lbs.

Post by **jcslocum** » Sat Oct 28, 2006 2:02 pm

Antti,

Regardless, HP is only a derivitive of Torque. I'm not sure (being in th USA) how the formula works forNm to KW but if I have time I will dig into it.

This is why engines that turn at high RPM can make so much HP.

Some extra reading:

http://vettenet.org/torquehp.html

Finnpaso · Post by **Finnpaso** » Sat Oct 28, 2006 2:26 pm

I check that site fastly and seems, that I start to be in same side, as You, Guys.... That "formula" was enough to me! :laugh: But with this my bad english i try to read more about that article, but not sure, can i understand all... :funny: Anyway this is very intersting thing....

Post by **jcslocum** » Sat Oct 28, 2006 2:56 pm

Antti,

You english is much better than our Finnish!!!!! I don't think I know one Finnish word. Teach us how to say hello in finland.

Finnpaso · Post by **Finnpaso** » Sat Oct 28, 2006 8:11 pm

Terve, Moro, Hei, Heippa, Morjens, Suikimaluikima, Tsau, Tsaukkis, Terse, Heipparallaa, etc... Here was only 10 first, so, when You guys learn all these, then i teach more... but maybe next lesson is those "naughty, bad words"

U have to know, them, if You want to know Finnish menthality.

persempre907 · Post by **persempre907** » Sun Oct 29, 2006 7:31 am

Finnpaso wrote:Terve, Moro, Hei, Heippa, Morjens, Suikimaluikima, Tsau, Tsaukkis, Terse, Heipparallaa, etc... Here was only 10 first, so, when You guys learn all these, then i teach more... but maybe next lesson is those "naughty, bad words" U have to know, them, if You want to know Finnish menthality.

Hi,
I know what it means "terve"

.
Of course, do you want go forward to the "naughty, bad words", so we understand the Finnish menthality?
But, you have to put the translation

Ciao