Author Topic: Wolf Classic 150 power specs....  (Read 5456 times)

pacnwfoto

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Wolf Classic 150 power specs....
« on: September 23, 2012, 09:31:24 PM »
Wolf 125 specs  
124.5 cc
Horsepower: 10.19 HP @ 8500 rpm
Torque: 6.6 ft.lbs @ 7500 rpm
http://www.bikez.com/motorcycles/sym_wolf_125_2012.php

Wolf Classic 150 specs
149.4 cc
Horsepower: 14.79 hp @ 8500 rpm
Torque: 9.04 lb/ft @ 9000 rpm
http://www.alliancepowersports.com/models/PDF/2012_Sym_Wolf150.pdf


The published power ratings for the Wolf 150 seen around the net have never seemed right to me.  First, 14.9 horsepower at 8500 rpm seems a bit of a stretch from a normally aspirated single-cylinder two-valve 149cc engine.  The Wolf 125 which is 24.9cc smaller produces a claimed 10.19 hp.  4.6 additional horsepower from the Wolf's extra 24.9 cc seems a miracle.  Marketing departments tend to fudge a bit with horsepower, so I'll accept it as exaggeration.  But, the torque claim just doesn't make sense.  I have never seen a dyno chart that showed peak torque produced at a higher rpm than peak horsepower.  You can wade through the math here http://en.wikipedia.org/wiki/Torque#Derivation , but the gist of it all is under the heading "Machine Torque" which states "Torque is part of the basic specification of an engine: the power output of an engine is expressed as its torque multiplied by its rotational speed of the axis. Internal-combustion engines produce useful torque only over a limited range of rotational speeds (typically from around 1,0006,000 rpm for a small car). The varying torque output over that range can be measured with a dynamometer, and shown as a torque curve. The peak of that torque curve occurs somewhat below the overall power peak. The torque peak cannot, by definition, appear at higher rpm than the power peak.

It all makes me curious what the Wolf's real power specs are.  I've surfed the net quite a bit and haven't found a dyno chart for either the Wolf 125, or the over-bored Wolf Classic 150.  If you've seen one, please post the URL.

« Last Edit: September 26, 2012, 02:33:53 AM by pacnwfoto »
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gitsum

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Re: Wolf power specs
« Reply #1 on: September 23, 2012, 10:36:46 PM »
I agree, the Wolf does not put out 14.79 horsepower.    I know this for sure because the HD 200 is supposed to make 15.2 horsepower, weighs 30-40 pounds more, and is much faster.  Even with a chain drive, 5-speed, and a clutch, the Wolf is no match for the HD 200 with an automatic scooter transmission.  Top speed is a good 10 mph higher than the Wolf too.

My son and I have done some drag racing with the HD 200 and the Suzuki TU250X which is rated at 16 horsepower.  The 5-speed transmission and clutch on the Suzuki give it an advantage off the line, but mid range speeds from 20 - 55 mph the HD 200 has the edge.  Top end the TU250X is probably 7 - 10 mph faster, and at speeds of 60 mph and over it is faster than the HD 200.

So I am inclined to agree that the claimed 15.2 horsepower of the HD 200 sounds about right.  By the same logic, I seriously doubt the Wolf's claimed output of 14.79 horsepower is accurate.  My guess would be more like 12 or maybe 13 horsepower at most.
« Last Edit: September 23, 2012, 10:39:21 PM by gitsum »

pacnwfoto

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Re: Wolf power specs [are wrong]
« Reply #2 on: September 24, 2012, 10:18:24 AM »
Have a look at line-4 of this 2012 EPA Motorcycle Certification Data.  It shows the Alliance/Sanyang Wolf Classic 150 [certificate CALPC.150SYM-003] having a power rating of only 9.2 kW (12.34 hp) @ 9000 rpm, not the 14.79 hp @ 8500 rpm claimed in marketing material.
 
www.epa.gov/oms/cert/documents/cert-tst/12-mc-ctrr.xls


Check the kW/HP conversion here http://www.convert-me.com/en/convert/power


I'm guessing about the generated torque lb/ft, but knowing that torque peaks at lower rpm behind horsepower, I think the Wolf specs should read:

Horsepower: 12.34 hp @ 9000 rpm
Torque: 9.04 lb/ft @ 8500 rpm
« Last Edit: September 24, 2012, 09:21:08 PM by pacnwfoto »
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Mr_Krabs

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Re: Wolf Classic 150 power specs [are wrong]
« Reply #3 on: September 24, 2012, 06:48:07 PM »
The conversion from torque to horsepower is as follows.

(Torque (lbs-ft) X RPM) / 5252 = HP

Now considering the 150 engine is basically just a bored out 125 engine, the torque curve ought to remain the same, just bumped up a little higher all around. But with similar construction and the same stroke, the peak torque and peak power ought to occur at the same RPM as the smaller engine. It certainly is true with the peak power so logically peak torque should too be at 7500 RPM. So the most likely scenario is this creates a peak torque of 9.04 lbs-ft at 7500 RPM.

At 9.04 lbs-ft of torque 7500 RPM you've got 12.9 hp on tap. So extending this with the same ratio of torque to horsepower of the 125 to 8500 RPM, gives us a maximum theoretical HP of 13.92 at 8500 RPM with our 150cc engine. If the RPM limit were raised and this is a naturally higher revving engine than the 125, then further extending this ratio to 9000 RPM would give 14.73 HP. Awfully close to the rating claimed by SYM.

This is calculated using the torque number from the 150cc engine but using the more realistic peak torque RPM from the 125. Engines are rather predictable when it comes to output when changing displacement and the 150cc engine, if the measured torque is correct, actually fits inline with the output.

If you notice the 125cc puts out more than 100 hp per liter of engine, actually rather modest when it comes to higher revving engines, and perfectly inline with air cooled technology. I know my Suzuki GS500F had about a similar HP to displacement ratio, 47 HP and 487 CC displacement, air cooled carbed just like the Wolf. So in the same boat it's perfectly reasonable to expect 14.79 hp out of the Wolf's 150cc bike considering it's actually got less power to displacement than the 125cc wolf.

Honestly I think the published numbers are right except for the torque's RPM measurement, it really should be at 7500 RPM as that fits more inline with the engine design and actually makes all the numbers make sense.

And one problem you've got comparing acceleration with the HD200 is that a CVT and higher torque engine makes for much quicker takeoffs because I know the Buddy 125 can outpace the Wolf off the line until I enter the higher power band and can take advantage of the power. It's why those high revving Honda's just feel so weak even though they have very good HP numbers. If all the HP is up top, you're not going to be able to use it and feel it on a daily basis. But I can tell you one thing. Comparing this to my old Honda Rebel with 18.76 HP the top speed of the Wolf isn't that bad. Honestly I think the Honda Rebel topped out at 75 mph and I know my Wolf can just about get to 70. So I'm apt to believe the HP claims.

Just remember these HP numbers are measured at the crank.
« Last Edit: September 24, 2012, 06:57:15 PM by Mr_Krabs »

gitsum

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Re: Wolf power specs [are wrong]
« Reply #4 on: September 24, 2012, 08:01:02 PM »
Have a look at line-4 of this 2012 EPA Motorcycle Certification Data.  It shows the Alliance/Sanyang Wolf Classic 150 [certificate CALPC.150SYM-003] having a power rating of only 9.2 kW (12.34 hp) @ 9000 rpm.

My seat of the pants dyno tells me that sounds about right.   Remember, the Wolf is only pulling around 265 lbs which is about 70 lbs less than the Suzuki TU250X, Honda Rebel, Yamaha V-Star 250 (Virago), Eliminator 125, and so on.  If you dump the stock battery and catalyst exhaust you can get that down to about 245 lbs.  I found the power output of the Wolf 150 was more than adequate for the kind of riding I used it for.   I would not take it on the interstate, but on 55 mph highways the Wolf does quite well with a 17t front sprocket ;)

It will hold 65 mph on faster roads, but I wouldn't want to run it that hard for more than a few miles.

Mr_Krabs

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Re: Wolf Classic 150 power specs [are wrong]
« Reply #5 on: September 25, 2012, 07:27:54 PM »
Oh yeah I forgot to add. EPA power measurements are at the wheel, which explains the lower 12.33 HP power rating. Manufacturer power ratings are almost always at the crank.

pacnwfoto

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Re: Wolf Classic 150 power specs [are wrong]
« Reply #6 on: September 25, 2012, 08:53:59 PM »
... EPA power measurements are at the wheel...

Can you verify?  IIRC, the EPA number is based upon the manufacturer's submitted Certificate of Origin for the vehicle tested which is crank hp.
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Mr_Krabs

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Re: Wolf Classic 150 power specs [are wrong]
« Reply #7 on: September 26, 2012, 01:09:41 AM »
I did look again it is crank for EPA HP. I was thinking CARB emissions ratings which are done on a dyno as a fully functioning bike. In fact on craigslist was recently posted the actual CARB test unit Sym Wolf. By the looks they really put it through it's paces as the exhaust header was entirely blue and yellow for the whole first foot or so of the header.

http://inlandempire.craigslist.org/mcy/3293384698.html

pacnwfoto

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Re: Wolf Classic 150 power specs [are wrong]
« Reply #8 on: September 26, 2012, 02:25:30 AM »
...on craigslist was recently posted the actual CARB test unit Sym Wolf....

$850 OBO is incentive to drive a long way to buy it, but without papers it doesn't officially exist.  :( 

That poor little pup got cooked.  The pipe is trashed, but the engine internals should be okay.  Sometime down the road there will be a wrecked Wolf with a title in a junk yard that could use that frame and front end.
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Mr_Krabs

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Re: Wolf Classic 150 power specs....
« Reply #9 on: September 26, 2012, 08:20:25 AM »
That might also explain the slight power discrepency. With the catalytic converter on board it may be restricting the exhaust and reducing power compared to the Asian versions that don't have cats.

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