EPA has released HP numbers

[Daag44]

No need to recalculate, you are correct, should be "Max Test Torque, Nm" not kW. To many dang conversions going through my few brain cells at that time.

You were right the first time, at least for the Polaris figures. Did you figure how to calculate the Hp for Doo?


I think the more important question is how the heck did Polaris pump that much Hp out of an 840??? The answer becomes easier to see when you start looking at the Hp per CC



From your earlier reply:


IMO the spreadsheet should read "max test power" instead of "max test torque"

 

[Ski-doo#1]

The EPA might be wrong on skidoos numbers. I think the KW ratings listed for Polaris are right, the numbers shown closely match last yrs independent dyno numbers so I have no reason to think what they posted is wrong... Also everyone has been saying 167hp for the 850 long before this was posted.

I thought maybe you would be right.

And then I did the same check but with the 800 E-TEC. Datasheet shows 133 kW (in your terms google converts that to 178 HP) so now you're saying two of their data points are wrong? Is Ski-doo under-marketing these sleds cause I never felt 178 HP stock from that motor.

Now, my way, instead of saying 133 kW, I say the EPA actually meant to say 133 Nm (Newton-Meters). Convert this to ft-lbs because that is the system of units that dynotech measures their torque.

133 Nm = 98.1 ft-lbf of torque according to EPA
Cross Reference check on dynotech research: 101.8 ft-lbf

98.1 ft-lbf is awfully close to 101.8 ft-lbf

Just have to come to accept that it is ironic that what you are calculating comes out to believable power numbers. It is only a coincidence.

 

[Ski-doo#1]

You were right the first time, at least for the Polaris figures. Did you figure how to calculate the Hp for Doo?


I think the more important question is how the heck did Polaris pump that much Hp out of an 840??? The answer becomes easier to see when you start looking at the Hp per CC



From your earlier reply:


IMO the spreadsheet should read "max test power" instead of "max test torque"

Daaaag, my friend, he was correct in his math but the EPA is not reporting power (kW) that he uses in his equation they are reporting torque (Nm)

 

[RMK-King]

Like I said before the skidoo results might have something going on with them... But I still believe the recent Polaris KW numbers are correct. If the EPA is wrong and its a coincidence that all 4 matched up almost perfect I better go buy a Powerball ticket lol.

 

[RMK-King]

I emailed the EPA and asked them to verify for me that the shown KW column on that PDF sheet is correct. I will let you know if they respond.

 

[Daag44]

Daaaag, my friend, he was correct in his math but the EPA is not reporting power (kW) that he uses in his equation they are reporting torque (Nm)

You are assuming the EPA is showing Torque in Nm for all of them when it's only for BRP. They are showing Power in kW for all the others. Don't ask me why because I have no clue.

Below is a link to a snapshop of a speadsheet I modified showing the 2019s.

https://www.dootalk.com/forums/topic/1541481-doo-850-torque-is-up-there/#entry22360665

 

[Daag44]

Also wrong, it should read "Max Test Torque (Nm)" The EPA is wrong. Cause the values in that column are torque values not Power and not kW values. They are Nm (Newton-Meter) Values.


You do that exact same calculation that you did above with the value for the Doo 850 on that spreadsheet and report back to everyone what your HP value is for the Doo 850. And then I will ask you: You still think it should say max test power?

"You still think it should say max test power?"

Ironically it was this one line that got me thinking we were making the wrong assumption that the column title was correct for all makes. So I kind of owe it up to you and richracer1 for working it out

I started with the notion that if the Hp didn't make sense then the calculations were wrong. It also helps to know that today's EFI 600 at seal level are roughly 0.2 Hp per CC (and increasing to 0.208), and the 800/840/850 are 0.194 Hp per CC. Of course this depends on fuel, break-in, oil, and whatever else we can think of.

 

[Daag44]

You can have power without torque but you can not have torque without power?

The dyno shows both torque and power. So it's just a matter of which of two is input into the spreadsheet.

 

[Daag44]

I emailed the EPA and asked them to verify for me that the shown KW column on that PDF sheet is correct. I will let you know if they respond.

If would ironic to send them a corrected version of the spreadsheet

Thanks for this thread. I couldn't make any sense of it until going through it a number of times thinking the answer was in here.

 

[nacapster]

Well working backwards I came up with the following from the EPA #s:



2018 Doo 850: 108.42 ft lbs & 163.08 HP @ 7,900 RPM
2019 Poo 840: 106.37 ft lbs & 167.09 HP @ 8,250 RPM



* This assumes the # for the Poo (124.6) is power in KW and the # for the Doo (147) is torque in NM.

 

[Ski-doo#1]

Well working backwards I came up with the following from the EPA #s:



2018 Doo 850: 108.42 ft lbs & 163.08 HP @ 7,900 RPM
2019 Poo 840: 106.37 ft lbs & 167.09 HP @ 8,250 RPM



* This assumes the # for the Poo (124.6) is power in KW and the # for the Doo (147) is torque in NM.

Yes, this is what I got as well. However, still the question arises, why does EPA say torque and label the units as power? Was it a mistake? I am excited to see if they respond to RMK King's email.

Glad we are all on the same page that something doesn't add up. Either the 840 is way down on power or the EPA is mixing units together. Hopefully find out soon.

 

[summ8rmk]

And the little Kitty with a measly 154hp..............


[emoji507][emoji192]

 

[Ratchit]

Looks to me like the doo’s were measured in the “newton meter”and not “kilowatts”by the epa charts. Totally different formula for (Nm) vs (Kw). That would explain the numbers in the epa charts better. The (Nm calculations)puts the doo 850 in the 160’s hp and kilowatts puts the poo 840 in the 160’s per calculated formulas . The 116.9 (Kw) x1.341= 156 hp on the poo 800 for 2019 and the 2017 poo 800 was 113.62 (Kw)x 1.341= 152 hp. Both those are close to Dynotech’s results.
I’m guessing the poo 840 will be165- 168 hp and 105-109 tq at dynotech .I’m taking two to the Dyno and will find out .

 

[akpowderhound]

I can’t wait to see how the new 840 lines up with the 850 on the mountain.
I’m sure it won’t have that low end the skidoo has, but I know my 800 Axys held its own against them this last couple years.

 

[Timbre]

Due to the Polaris 850's ability to get power to the snow more efficiently than the doo doo 850, I gotta give the nod to the Polaris. The 800 axys was dead even with the supposedly higher powered doo 850, so with the added power on the Axys 850 this year, Polaris will be hands down the better sled this season.

 

[goridedoo]

Due to the Polaris 850's ability to get power to the snow more efficiently than the doo doo 850, I gotta give the nod to the Polaris. The 800 axys was dead even with the supposedly higher powered doo 850, so with the added power on the Axys 850 this year, Polaris will be hands down the better sled this season.

Supposedly? Assuming you have not ridden an 850 Doo? Hands down more low and midrange than the Poo 800.

Also seems a bit early to call it the better sled hands down when only a few have ridden prototypes/early builds.

 

[NoNonsense]

All the numbers you see in that spreadsheet are submitted by the manufacturer. The EPA doesn't actually test anything unless the manufacturer is audited, and if so, they hire a 3rd party. The 3rd party will likely come up with different power numbers than the manufacturer. They require the manufacturer to come up with a duty cycle using this general rule of thumb, which isn't necessarily based on J1349 (SAE automotive standard). They just have a few suggestions to get a consistent number, so the 5 mode test can be determined and the emissions data is accurate on a PPM basis.
https://www.law.cornell.edu/cfr/text/40/1065.510

For this reason, these numbers are not an apples to apples comparison.

There is a template here that the manufacturer is required to fill out.
https://www.epa.gov/vehicle-and-engine-certification/certification-snowmobiles

The torque and power part of this conversation gave me a headache - power is the rate of usable work or the rate of energy transferred per unit time. There is a direct relationship between torque and power at a given speed. Always. Yes, you can have high torque and lower power, but all depends on your torque at the given speed. You can also have low torque and high power if you're revving the engine to the moon, but they are always related.

 

[Timbre]

Supposedly? Assuming you have not ridden an 850 Doo? Hands down more low and midrange than the Poo 800.

Also seems a bit early to call it the better sled hands down when only a few have ridden prototypes/early builds.

Yes, supposedly. This is based on my experience riding the 850 doo. If it had more power, it does not get it to the snow as efficiently as the axys.

 

[goridedoo]

Yes, supposedly. This is based on my experience riding the 850 doo. If it had more power, it does not get it to the snow as efficiently as the axys.

I disagree... strongly but thats ok... back to fancy engineer math stuff.

 

[Daag44]

All the numbers you see in that spreadsheet are submitted by the manufacturer. The EPA doesn't actually test anything unless the manufacturer is audited, and if so, they hire a 3rd party. The 3rd party will likely come up with different power numbers than the manufacturer. They require the manufacturer to come up with a duty cycle using this general rule of thumb, which isn't necessarily based on J1349 (SAE automotive standard). They just have a few suggestions to get a consistent number, so the 5 mode test can be determined and the emissions data is accurate on a PPM basis.
https://www.law.cornell.edu/cfr/text/40/1065.510

For this reason, these numbers are not an apples to apples comparison.

There is a template here that the manufacturer is required to fill out.
https://www.epa.gov/vehicle-and-engine-certification/certification-snowmobiles

The torque and power part of this conversation gave me a headache - power is the rate of usable work or the rate of energy transferred per unit time. There is a direct relationship between torque and power at a given speed. Always. Yes, you can have high torque and lower power, but all depends on your torque at the given speed. You can also have low torque and high power if you're revving the engine to the moon, but they are always related.

Good to know on the certification requirements and process.

I was making an assumption on how the EPA was inputting the wrong information in the spreadsheet from their own tests, but hopefully you assertion that the results were in fact taken from the manufacturer is accurate and from personal knowledge of the matter. In any case I guess it doesn't really matter as I'm guessing we aren't working for the manufacturers nor the EPA. Of course I have known some who did and posted on a public forum, so we never know.

As for the headache, I don't see a reason for it in this thread. The math was good and the understanding was excellent. We are not 14 years old debating why some prefer to focus on Torque while others focus on Power. The only problem was the column title and the conversion from SI to STD units. So if there was any head ache to be had, those are the things that should be blamed, not us regular sled owners trying to make sense of a mistake that we didn't even make.

Instead maybe give credit where credit is do. As I have said on DooTalk, these guys on SnoWest helped me sort out the confusion.