This is along the lines of the recent thread about claimed weights. As Rich pointed out in that thread, the manufacturers usually have a way to defend their numbers.
Here's a few ways KTM can get such a high number:
1) Use crankshaft HP, not rear wheel hp
2) Run it in a pressurized dyno room with extra oxygen pumped in and don't correct for standard atmospheric conditions.
3) Allow a wide range of squish band height and combustion chamber volume on the spec sheet, and make sure that the engine you dyno is at the extreme end of the range for max HP.
4) Special fuel
With the exception of professional riders and tuners, people should stop paying attention to peak HP figures, IMO.
Here's a few ways KTM can get such a high number:
1) Use crankshaft HP, not rear wheel hp
2) Run it in a pressurized dyno room with extra oxygen pumped in and don't correct for standard atmospheric conditions.
3) Allow a wide range of squish band height and combustion chamber volume on the spec sheet, and make sure that the engine you dyno is at the extreme end of the range for max HP.
4) Special fuel
With the exception of professional riders and tuners, people should stop paying attention to peak HP figures, IMO.
All the manufacturers exagerate their horsepower numbers. These numbers are arrived at by using a hand-picked, perfectly assembled engine, running on a dyno in a perfect environment, and they report crankshaft numbers, not rear-wheel numbers. Driveline losses can easily exceed 20%. If I remember right, Honda claimed 55 hp for the '01 CR 250. Does anyone here think that is a realistic figure? It's all marketing strategy.
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Not that I believe anything written in a magazine or claimed horsepower figures, but quoting this months Dirt Rider article, regarding the KTM125, page 48 -
"We hear reports that the works KTM's pump out 41 horsepower at the rear wheel on the dyno. KTM's 2000 model 250SX made 37 horsepower on the same type of dyno. The motor remains the magic in the 125SX package."
It sounds like they're saying that the works 125SX puts out more peak power than the production 2000 250SX.
There's nothing stopping anyone from embellishing the numbers or creating a little hype. :confused:
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Not that I believe anything written in a magazine or claimed horsepower figures, but quoting this months Dirt Rider article, regarding the KTM125, page 48 -
"We hear reports that the works KTM's pump out 41 horsepower at the rear wheel on the dyno. KTM's 2000 model 250SX made 37 horsepower on the same type of dyno. The motor remains the magic in the 125SX package."
It sounds like they're saying that the works 125SX puts out more peak power than the production 2000 250SX.
There's nothing stopping anyone from embellishing the numbers or creating a little hype. :confused:
Kawasaki used to (still?) measure their roadbike (& presumably dirtbikes) hp by reading rear wheel hp then removing the top end & rod driving the engine up to speed with an electric motor to calculate loses, add that onto the original run & claim that as crank hp.
The logical progression is to measure fuel consumption, assume no losses & claim the calorific value of this. 100 hp 125 no wurries!
Mid 30s for a 125 is pretty good. But what is the potential? Well RS125 Road racers were originally derived from CRs. The early ones wheezed out 30hp 10ish yrs ago. Now they are seeing mid 40s on proper gas & setup & some top level tuners are now expecting to graze 50 but these are like works level.
‘course before you salivate too much the development paths separated a while back but more importantly one of these engines in the dirt would be unrideable, even for factory riders unless you removed the dirt, the corners, the need for acceleration. . .
The logical progression is to measure fuel consumption, assume no losses & claim the calorific value of this. 100 hp 125 no wurries!
Mid 30s for a 125 is pretty good. But what is the potential? Well RS125 Road racers were originally derived from CRs. The early ones wheezed out 30hp 10ish yrs ago. Now they are seeing mid 40s on proper gas & setup & some top level tuners are now expecting to graze 50 but these are like works level.
‘course before you salivate too much the development paths separated a while back but more importantly one of these engines in the dirt would be unrideable, even for factory riders unless you removed the dirt, the corners, the need for acceleration. . .
Sorry to spoil KTMs fantasy but from 99-01 the 125sx has put out roughly 32-33hp.it depends on which bike on which day.Each year the peak Hp has been the same but the engine has got easier to ride on the later models.A well sorted 01 with mods puts out 35hp.I dont beleive any manufacturer when they claim 3hp more than last year.3hp on a 125 is a huge amount that takes years to acheive.Even if we had langstons barrel it wouldnt be setup the same a his bike.The crankcases/transfers arnt matched on a production engine.The squish clearnances will be bigger due to pump fuel.He runs a v force on his as well as a DOMA pipe etc. These claims of 41 hp are put about to send the rivals to the dyno room to ruin there engines making them more peaky.Ive seen dynos of World GP bikes and they arnt 41hp-not even close. Factory tuners look for a very straight line on the dyno-peak numbers are a waste of time.MX is about torque not HP.