I was merely pointing out the difference with a hub dyno as some people assume that all dynos measure power at the wheels. When you quote "fwkw" as you have - people think you are talking about power at the wheels.Originally Posted by mattyd
yfin - not to be a smart arse, and all due respect with the next question, are you speaking from experience when comparing dynos? granted that it is a hub dyno vs a roller dyno, however i cannot really see that there would be much of a difference in friction of tyres to steel rollers and hubs which are attached which mimmic tyre contact to road. Both dynos, when used correctly are there not to just measure power out put, are also there to provide load on gear box and engine when tuning a vehicle, load meant to be close to what would be experienced on the road... providing indications of when in the rpm the vehicle will need more fuel added to the mixture, or more spark and when to advance timing. I dont even think it is really possible to obtain the same power figure on 2 different dynos at 2 different workshops??!
That figure I quoted of 10-15% higher figure being shown on a hub dyno was something James' advised me -ie the person who tuned your car. It is not a rigid fixed percentage - it is a generalisation comparing it to something common like a Dynodynamics rolling dyno.
And of course, different dynos will produce different results - but a hub dyno produces a higher result. I am not flaming your result in the slightest - it sounds like a very nice car. Your before and after results are really what is important. Any chance you can post up a base line on that dyno so we can really see the difference? Cheers
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