Guest JMW Posted November 11, 2004 Share Posted November 11, 2004 I've been trying to get a handle on this for a while. I spent a few hours dyno-ing 5 2 stroke spannies and after looking at the torque and BHP figures and comparing them to other bikes I've run, there doesn't seem to be a direct relationship between the two values. EG.. A bike making 80bhp delivers 65Mn's of torque yet a similar bike making 85bhp delivers 60Mn's of torque. With no discernable difference, what would cause the torque figure to drop when outright engine power is up ? Any takers ? J Link to comment Share on other sites More sharing options...
gavin Posted November 11, 2004 Share Posted November 11, 2004 ive already explained ths one to you once before, on aleks forum, in a thread you started http://www.yamaha-rd.com/forum/viewtopic.p...t=5250&start=36 power = torque x revs/5250 so, by calculation a bike making 80bhp at 10,000rpm has 42lb-f of torque. but another bike making 80bhp at 9000rpm has 46lb-f of torque. the higher up the revs it makes the power, the less torque it has. there is also a difference between torque at peak power, and actual peak torque. its quite possible for a bike that maks loads of power on a dyno at sky high revs to have bugger all torque, and so never actually make that power on the road, because it will never be able to overcome the rolling and wind resistance. just proves you never listen Link to comment Share on other sites More sharing options...
gavin Posted November 11, 2004 Share Posted November 11, 2004 just for my amusement ive been playing with your numbers 65Mn (Mewton Neters? ) is 47.94lbf 60Nm is 44.25lbf so assuming you havent just plucked these numbers out of your head bike no1 makes peak power of 80bhp at 8,761rpm or thereabouts bike no2 makes peak power of 85bhp at 10,085rpm or thereabouts right? i say thereabouts, because theres a little rounding in the calculation. Link to comment Share on other sites More sharing options...
johnalpi Posted December 1, 2004 Share Posted December 1, 2004 LOL @ bike no1 makes peak power of 80bhp at 8,761rpm or thereabouts 8,761rpm or there abouts? +/- 1rpm, Link to comment Share on other sites More sharing options...
gavin Posted December 1, 2004 Share Posted December 1, 2004 LOL @ 8,761rpm or there abouts? +/- 1rpm, maybe...whats your point? Link to comment Share on other sites More sharing options...
johnalpi Posted December 2, 2004 Share Posted December 2, 2004 Link to comment Share on other sites More sharing options...
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