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Old 10-27-2012, 03:33 AM   #91
RGregor
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Joined: Oct 2007
Location: Bavaria
Oddometer: 437
Quote:
Originally Posted by Kai Ju View Post
Let the flaming begin..........
I agree a 100%.
Additionally I would say that, having no before-after comparison, the shape of a torque curve will give valuable information even if you can't trust the numbers.
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Old 10-27-2012, 12:58 PM   #92
supershaft
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Location: San Francisco Bay area
Oddometer: 8,012
Now we are getting somewhere! Torque curves? I have been going on about how different dyno's and operators will get different readings with the same bike? Well, I am talking about peak hp readings. Duplicating low and midrange numbers or curves is even more subjective many times over. I look at numbers AND curves with a grain of salt. The further the curve is from peak hp the more suspect I become. Depending on the situtaion, I would much rather have first hand accounts.

It's the same IMO with off idle jetting. You can get it in the ball park on the dyno but it is pure luck if that is what it really needs. That almost always takes riding it in the 'real world'.
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Old 10-28-2012, 04:48 AM   #93
RGregor
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Joined: Oct 2007
Location: Bavaria
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Quote:
Originally Posted by supershaft View Post
Now we are getting somewhere! Torque curves? I have been going on about how different dyno's and operators will get different readings with the same bike?
Yes. The readings can differ extremely, but they don't necessarily have to.
I've been to three different dynos (2 inertia and one brake dyno) and the results were pretty close.
I don't mean that you can take any diagram figures for granted, but still I believe that a lingual description can be misleading as well.

Quote:
Originally Posted by supershaft View Post
Well, I am talking about peak hp readings. Duplicating low and midrange numbers or curves is even more subjective many times over.
I chose the last dyno as the owner knows very well how to operate it. He did many runs on a row and the curves are almost identical. But yes, that may/will depend on operator and dyno.

The dyno you were to, is the brake operated manually? May be hard to reproduce results then.

Quote:
Originally Posted by supershaft View Post
I look at numbers AND curves with a grain of salt. The further the curve is from peak hp the more suspect I become.
Depending on the situtaion, I would much rather have first hand accounts.
Being careful is always a good idea.
Again my english: what do you mean by "the further the curve is from peak hp" and "first hand accounts"?

Quote:
Originally Posted by supershaft View Post
It's the same IMO with off idle jetting. You can get it in the ball park on the dyno but it is pure luck if that is what it really needs. That almost always takes riding it in the 'real world'.
The exhaust gas analyzer showed that my 'real world' jetting was good.
But it also showed, that the pumps were not working properly. After fixing them improvement on the road was very positive.
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Old 06-25-2013, 11:30 PM   #94
stirts
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Joined: Jun 2013
Location: New zealand
Oddometer: 8
Quote:
Originally Posted by Voltaire View Post
Its not as fast as Pukekohe, but that's what he said.....I was running a 3.0.
I bought a set of big valve 1977 heads after Puke....then it was mentioned that the D port R80 heads are the better ones to start with.....got a set of these too...... head work on BMW's seems to be cloaked in secrecy.....

The BMW sidecar dropped a valve seat before even doing a lap..... and the ring lands were pushed together a bit.... Maxheadroom ( Nick) found a stock r100 head, swapped over the valves and rockers....carefully took the rings out...dressed the piston in the lathe.... and....

With this set up they managed a 3rd and a 4th...newish rider and different swinger.
I suggested they put it on the Dyno, disconnect one lead at a time and see which has more power.....
Apparently it ran the same but riders leg tended to blocked the carb
Hey that's a pretty good looking sidecar, I hear the rider is quite good looking too, and fast!

The sidecar is broken (again) at the moment, please see this thread for details - http://www.advrider.com/forums/showt...7#post21728457
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