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Discussion Starter · #1 ·
Ok, I have been contemplating getting a R3 but I am a bit concerned about the HP ratings being seen in production R25s and from @jbluetooth dyno runs.

http://www.rushlane.com/yamaha-r25-delivery-12126580.html

http://indianautosblog.com/2014/06/yamaha-r25-dyno-test-134765

http://www.yamahar3racing.com/category/dyno-testing-and-tuning/

Each of these is a bit concerning to me being that I want to race it and would be going up against the KTM RC 390. The KTM has consistently posted dyno runs in the 40 hp range.

I know each dyno is different but 20% difference between what Yamaha is claiming and what is being seen is nuts!

Opinions?
 

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Ok, I have been contemplating getting a R3 but I am a bit concerned about the HP ratings being seen in production R25s and from @jbluetooth dyno runs.

http://www.rushlane.com/yamaha-r25-delivery-12126580.html

http://indianautosblog.com/2014/06/yamaha-r25-dyno-test-134765

http://www.yamahar3racing.com/category/dyno-testing-and-tuning/

Each of these is a bit concerning to me being that I want to race it and would be going up against the KTM RC 390. The KTM has consistently posted dyno runs in the 40 hp range.

I know each dyno is different but 20% difference between what Yamaha is claiming and what is being seen is nuts!

Opinions?
The majority of dyno runs show the stock R3 at around 37 rear wheel horsepower.

No one is sure why jbluetooth's dyno run was so low compared to all the others. Something with their set-up or software, maybe.
 

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Discussion Starter · #4 ·
The difference has been coming in with the R3s sold to consumers. The ones sent to the magazines were consistently at, or near, what Yamaha was stating. If you check the two R25 dyno in the links the runs they did couldn't come anywhere near what Yamaha was claiming.

Anyone else have dyno runs done?

KTM has a very small tank, really not that good for street.
I would only be using it for racing so that doesn't matter to me. I try only to have about 1 to 2 gallons in my tank during a race. Any extra is just added weight I don't need. Unless, of course, doing an endurance race.
 

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Discussion Starter · #6 ·

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VERY important note:

All of Yamaha's claims are for HP at the crank. They're measured with an engine on a stand in a test chamber, not in the bike.

Dyno runs show HP at the rear wheel, or more accurately, at the interface of the tire on the dyno roller.

There are significant losses in HP between the crank and the rear wheel all caused by friction (transmission losses, chain/sprocket interface losses, rear axle losses, tire slippage losses, even air resistance losses from the tire, wheel and spokes turning). Some may be minor but they all add up.....In the case of the R3 it's a loss of about 5 HP from the crank to the rear wheel (c.42 down to c.37). that's a 12% loss.
 

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That was a pre production model though destined for R&D, not some random bike purchased off the showroom floor.
And what exactly do you think would be different between it and a 'random' bike from the production floor?? Just because it says it was for development doesnt mean it was pre-production, could have been the first Canadian model off the production floor and was shipped over with the show models which traveled the country in January. No one knows for sure except the guys at Yamaha.

You could take the same bike/car/truck and put it on 5 different dynos and I guarantee there will be a variance in every result.

MAYBE there was a difference in fuel mapping, the point is, the R3 is more than capable of producing the figures shown in that graph given the right Dyno/Air Temp/Humidity/Hot run/cold run/Exhaust temp/Elevation etc..

I personally doubt this graph is any different than what my R3 bought off the 'showroom floor' would put down on the exact same dyno with the the exact same conditions.

If you're really that worried just buy an RC390
 

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I would only be using it for racing so that doesn't matter to me. I try only to have about 1 to 2 gallons in my tank during a race. Any extra is just added weight I don't need. Unless, of course, doing an endurance race.
If you are looking at racing the 300 class (D Superstock, etc.), you really should talk to some of the guys who have been racing the RC390 before buying. I love the 390 and almost bought one, but it has had some significant durability issues, among other things that figured into me opting for the R3.....
 

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Here's a video of how they dyno test each engine in the factory. This is for KTM, but they all do it in a similar way.

For HP claims on a press release or Specs shown on their site they do more extensive testing of an engine, but on the same or similar set up.

https://www.youtube.com/watch?v=c37esaT1a04

And here's another of the test run of each bike after assembly: Not a dyno run but just to make sure it all works.

https://www.youtube.com/watch?v=0CAfUWslP5I

Starts at 3:10 into the video
 

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If you are looking at racing the 300 class (D Superstock, etc.), you really should talk to some of the guys who have been racing the RC390 before buying. I love the 390 and almost bought one, but it has had some significant durability issues, among other things that figured into me opting for the R3.....
Not to mention their problem with some of their wheels breaking. It was probably the result of hitting potholes in India but it sure doesn't inspire confidence!

Tire Automotive tire Orange Automotive wheel system Wheel

Alloy wheel Tire Wheel Automotive tire Rim

Tire Automotive tire Wheel Alloy wheel Vehicle

Vehicle Tire Automotive tire Bicycle wheel Bicycle tire

NOTE: That last one was not from a high speed crash, but was a low speed crash after the rider had just left an intersection from a stop.

http://www.xbhp.com/talkies/motorcy...-duke-390-owners-reviews-experiences-233.html
 

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Discussion Starter · #12 · (Edited)
I understand dyno variations. That doesn't explain a 20% variation! Yes, I would expect a 4-5%, even 10%, variation. What about the "variations" they are seeing in the R25s, even with repeated runs? They are getting a 15% variation.

Where would the difference in fuel mapping come from on a stock bike with no modifications to account for the difference.

No I am not trying to accuse Yamaha of lying. I am just concerned about what is being seen out there right now.
 

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I understand dyno variations. That doesn't explain a 20% variation! Yes, I would expect a 4-5%, even 10%, variation. What about the "variations" they are seeing in the R25s, even with repeated runs? They are getting a 15% variation.

Where would the difference in fuel mapping come from on a stock bike with no modifications to account for the difference.

No I am not trying to accuse Yamaha of lying. I am just concerned about what is being seen out there right now.
I'd say any large variations on one dyno over several runs are the result of problems with the dyno, not the bike.
 

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Discussion Starter · #14 ·
I know I shouldn't be so concerned about HP. Yamaha reliability is one of the reasons I was leaning towards the R3. Plus it is a twin, better dealer network, cheaper engine parts, cheaper aftermarket parts, etc...

As for the KTM wheels, that is some scary stuff! Also, the KTM engine reliability issues is concerning. But we are also talking about race bikes that are put under huge loads. We don't know how the Yamaha will react under those same conditions yet since there are not a lot out there on the track.
 

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Discussion Starter · #15 ·
I should add, the 15% variation for the R25 I am referring to is the difference between what Yamaha is stating and what the testers were getting from their dyno. It sounds like they were getting consistent dyno results, just never up to, or close to, what Yamaha is advertising.
 

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I know I shouldn't be so concerned about HP. Yamaha reliability is one of the reasons I was leaning towards the R3. Plus it is a twin, better dealer network, cheaper engine parts, cheaper aftermarket parts, etc...

As for the KTM wheels, that is some scary stuff! Also, the KTM engine reliability issues is concerning. But we are also talking about race bikes that are put under huge loads. We don't know how the Yamaha will react under those same conditions yet since there are not a lot out there on the track.
Single cylinder bikes have never really been the best choice for racing. The torque is usually great but the stresses on the engine are greater, in general, than for twins, triples, fours.

KTM 390s do also have issues with build quality, vibration, engine stalling, over-heating, etc. That will most likely get ironed out down the road, but for now? I'm leery of them. I test rode an RC390 and it's a VERY uncomfortable bike for street riding.

A nice little Yamaha R4, 400cc 4-cylinder would be sweet! Just imagine the song from that engine with a good aftermarket exhaust on it!
 

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I should add, the 15% variation for the R25 I am referring to is the difference between what Yamaha is stating and what the testers were getting from their dyno. It sounds like they were getting consistent dyno results, just never up to, or close to, what Yamaha is advertising.
Manufacturers do not specify HP at the real wheel, which is what is measured at dynos. Have you considered this?
 

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Last weekend I rode with a few buddies and we had the trifecta going on. Me on my R3, a buddy on a Ninja 300, and another buddy on a 390 Duke. It's evident the KTM has some better stock parts on it (we've all been comparing these three bikes up against each other) but when it came down to ridability, the KTM was lacking (IMO). I know the three of us are different weights, heights, etc....but when we hit some straights and gassed it, we left that KTM behind every time (surprisingly!). I of course can't take into account our corning speeds because that's more on the riders experience level. The smaller gas tank, and a slightly bigger engine, that thing is a gas hog in comparison. He was getting something like 120miles to the tank. I have to admit though, the KTM does sit up higher in every aspect...even the ground clearance. I'd imagine you can lean that puppy down a little further than the R3 or Ninja (though I would never ask another guy to test ride his bike).






Most people have said it on many other posts in this forum, the KTM is a better bike for the track simply because it has less needed for its prep. But $$ for $$, HP for HP. MPH for MPH, etc..... I do believe the R3 is the better choice. Again, only my opinion....slightly bias as I own one :)
 

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Manufacturers do not specify HP at the real wheel, which is what is measured at dynos. Have you considered this?
Exactly.

My re-post from up above....

VERY important note:

All of Yamaha's claims are for HP at the crank. They're measured with an engine on a stand in a test chamber, not in the bike.

Dyno runs show HP at the rear wheel, or more accurately, at the interface of the tire on the dyno roller.

There are significant losses in HP between the crank and the rear wheel all caused by friction (transmission losses, chain/sprocket interface losses, rear axle losses, tire slippage losses, even air resistance losses from the tire, wheel and spokes turning). Some may be minor but they all add up.....In the case of the R3 it's a loss of about 5 HP from the crank to the rear wheel (c.42 down to c.37). that's a 12% loss.
 

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As for the KTM wheels, that is some scary stuff! Also, the KTM engine reliability issues is concerning. But we are also talking about race bikes that are put under huge loads. We don't know how the Yamaha will react under those same conditions yet since there are not a lot out there on the track.
Single cylinder bikes have never really been the best choice for racing. The torque is usually great but the stresses on the engine are greater, in general, than for twins, triples, fours.
!
The thumpers apparently don't like being wound up for very long. I worked one of the KTM cup race weekends - three engine-related failures in the first practice session - not sure what the final count was for the weekend. And these are the de-tuned versions - word is last year's eurocup, 25 or so would grid, 15 or so would finish (very few DNF's due to crashes). Race bikes, yes - typical failure rate for a race bike, no. If I manage to grenade the R3 this year, then I'm covered by warranty - after that, I'll be ticked if I don't get at least two seasons...
 
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