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Horsepower/Torque

6666 Views 2 Replies 3 Participants Last post by  hilleyja
I have seen different claims of horsepower and torque for Liners ranging from 86 to 91. So I did a search for sites with horse power and torque for Liners. Three interesting sites came up.

Motorcycle Cruiser an Internet magazine has had two articles since 2006 indicating 91 horsepower and 117 ft lbs torque at the rear wheel, for a stock bike.
http://www.motorcyclecruiser.com/roadtests/2006_yamaha_star_roadliner/index.html


Rider magazine has article indicating 87.1 horsepower and 107.2 ft lbs torque, at the rear wheel stock.
http://www.ridermagazine.com/output.cfm?id=1202131

The most interesting site from Pacific coast Star shows Dyno charts for most Star bikes. Two runs, one stock and one after some modifications. They don't say what modifications. Stock Liners being 86.86 horsepower and 112.63 ft lbs torque. After modifications, 95.73 Horsepower, and 118.86 ft lbs torque.
http://www.pacificcoaststar.com/pcs/yamaha_dynos.htm

Dave
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Hi Dave, i know a hotrod guy or two that have done engine dyno and then proceeded to do the rear wheel dyno. they found that the drive train differences were very profound. one of the guys had higher engine HP/TQ but ended up with less at the rear wheel due to frictional losses. i think the variance we see are the diffences in each bikes friction. there are many parts to consider. trans, T-case, wheel bearings and i would imagine the more your bike is broke in the freer it will spin - to a certain point. a new bike on the dyno will have more grease in the bearings, everything will be tighter because its new, hence more friction. someone with one summer of hard riding like me may actually have higher HP/TQ at the rear wheel because i'm all broke in. i put on 11,000 mi this last summer after i bought it new end of march. it seems to have more snot now that when it was brand new. it would have been nice to dyno it and then do it now to see if there is a difference. if anybody has done this plz let us know the results.
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I have seen different claims of horsepower and torque for Liners ranging from 86 to 91. So I did a search for sites with horse power and torque for Liners. Three interesting sites came up.

Motorcycle Cruiser an Internet magazine has had two articles since 2006 indicating 91 horsepower and 117 ft lbs torque at the rear wheel, for a stock bike.
http://www.motorcyclecruiser.com/roadtests/2006_yamaha_star_roadliner/index.html


Rider magazine has article indicating 87.1 horsepower and 107.2 ft lbs torque, at the rear wheel stock.
http://www.ridermagazine.com/output.cfm?id=1202131



The most interesting site from Pacific coast Star shows Dyno charts for most Star bikes. Two runs, one stock and one after some modifications. They don't say what modifications. Stock Liners being 86.86 horsepower and 112.63 ft lbs torque. After modifications, 95.73 Horsepower, and 118.86 ft lbs torque.
http://www.pacificcoaststar.com/pcs/yamaha_dynos.htm

Dave
Those numbers are fairly close and consistent with the numbers I got last summer when I had them do a custom map on my Dyna Power Commander: 86.9HP 116lb torque
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