A question we get asked at least once a day is why the power measured on our rolling road dyno is not the same as the power claimed by Triumph. This wonderful article from the glory days of motorcycle journalism spells out why that is. Get your tea and biscuits and enjoy: http://www.motorcyclenews.com/news/...sic-john-robinson---great-powertrain-robbery/
They ARE cheating bastards! The car is not even out on the road when they do the tests!!! Just a feckin "simulation", no aerodynamics or hills or traffic, it really is a load of bollox. Should be made to actually drive the cars around a course, stop, go, up and down hills. Never gonna happen.
Did anyone else start to think that the internal combustion engine is a bit crap when it comes to turning petrol into a force to push you down the road? It's no wonder we'll all be driving electric cars and riding electric bikes very soon............................................
That was an interesting read. Thanks for sharing it. I have just had my speed triple remapped and put on the dyno. First run (stock) gave 110 RWhp +20% = 132 Bhp at the crank. Post flash gave 122RWhp +20% = 146.4 Bhp at the crank. Interestingly the first run was slightly under what Triumph claim even with a generous 20% transmission loss factor. It's still not as quick as my S1000R was, but better all round. Regards to all Matt
To be honest Matt I reckon all the mfrs published finished are just tosh - there's only one way of measuring effective power and that is on a bench, at the back wheel. All the rest is just so open to debate.
Most energy sources converted into useful power are just as inefficient. Petrol 4 strokes are between 35% efficient, latest diesels are up to 45% efficient. But power station, Coal or Gas are around the same percentage efficiency, even wind turbines are only 45% efficient, but the source is free. The most efficient energy is Hydro, close to 85% efficient. Petrol engines make mostly heat, 1/3 as heat thru the exhaust and 1/3 as heat thru the cooling system and the last 1/3 as actual power. Quite poor really.
When triumph 1st started out (91) they were actual rear wheel figures but looked bad against the opposition
On the other hand quoting rear wheel horse power allows you to get a more powerful bike sitting just above a category limit into a lower class without needing to restricting it. Fortunately/Unfortunately the power to weight limitations put an immediate end to this disingenuous practice.
The manufacturers must surely use a blue printed engine to set the bhp figures when claiming what the engine makes. What we get then is pot luck as to how close to the claimed bhp the engine is due to volume production, although modern engineering tolerances, materials, designs, and assembly techniques are way better than they used to be. A good read, I’d forgotten how much detail John Robinson went into when talking about engineering. He clearly knew his stuff and I for one learned a lot from reading his articles, though some found him boring for going to the “nth” degree.
I always give limited credence to many of these figures for all the reasons outlined - not least taping all the panel joints on cars to improve mpg figures before they were tested on rolling roads in sheds..... From a personal satisfaction perspective I remember taking my Cobra to a tuning specialist to set up the carburation. Once the emissions curve looked ok the bloke was a bit crestfallen because my overbored self built 5.7 V8 was pushing out more than his nominally 400 bhp dyno could handle. Having reached the years of wisdom that sewed the first seed in my head that I should enjoy it carefully and sell soon. On public roads torque wins hands down for relaxed driving and opportunistic overtaking.