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Offline REDRIDER

Why so little HP
« on: July 11, 2017, 01:31:36 PM »
I was just thinking the other day. Why do these UTV's make such little HP for the engine size. An 800cc bike engine can easily make over 100hp why are we stuck with under 70? Just curious.

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Offline Andrew1au

Re: Why so little HP
« Reply #1 on: July 11, 2017, 06:50:28 PM »
Well Im not expert, But i would assume it comes down to the parts used to make the engine.

The old saying is you get what you pay for. Lets be honest here, 95% of CFMoto buyers base a big portion of their buying decision on Price.
They are cheap. Granted they are no Ebay Special, but still a cheap UTV nevertheless. If you want to spend the money one a Polaris or slimier, you get the HP you are talking about. Im not sure about your county though, but here in Australia, a Polaris is literary more than double the price of a CFMoto.

Higher price is due to higher costs. Further engineering and development. Higher quality parts. It may well be the small things that add up.
A better ECU program, better injectors, higher quality steel capable of taking more heat. The list could go on and on.

But as I said, this is simply an assumption by myself.
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Offline NMKawierider

Re: Why so little HP
« Reply #2 on: July 11, 2017, 07:19:50 PM »
Can you imagine how may CFM parts would shred themselves into the trash can if they were subjected to 100+ HP? As is these just barely stay together. Everything from the tip of that crank to the tire along with everything that holds them would have to be upgraded...not to mention a complete engine redevelopment. Let's say they did all this. Would you pay as much for a CFM as a Polaris or Can Am? Not me...lol I think there is an X3 in my future...love that thing...hate the cost though. 
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Offline REDRIDER

Re: Why so little HP
« Reply #3 on: July 12, 2017, 07:22:41 AM »
I'm not talking about only CFM, none of the UTV's are pushing the kind of HP they could be for their size. Snowmobiles have more HP than any of these things by about double.

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Offline chuddly

Re: Why so little HP
« Reply #4 on: July 12, 2017, 10:02:30 AM »
It is because of the intended use of each motor.  Your looking at sport bike engines and that machine fully fueled is roughly half the weight of a UTV.  On top of that they have nearly 0 torque LOL.  They dont need it.  They only have to turn 1 wheel via a chain (more efficient) and carry 1 person most of the time and they will NEVER tow or haul anything.  Now think about how a lot of people use their UTV?  4wd robs power.  2 wheels turning at minimum.  A whole lot of people put bigger tires on  that weigh more.  then they toss in a cooler that weighs 150lbs when fully loaded LOL.  Then they want to tow a boat around the yard or load a trailer with firewood.  One is made for speed and high revs with a clutch .  The other is made to be a multiple use engine with 4wd.  Its hard to have 1 engine do it all.  There are guys that have swapped sport bike engines into UTV's over the years.  They are fast.  But not good on tight trails and they no longer haul things well and 99.999% of the time they are 2wd ONLY machines for the rest of their lives.
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Offline REDRIDER

Re: Why so little HP
« Reply #5 on: July 12, 2017, 10:18:45 AM »
most of what you said relates to power loss through the drivetrain system which I understand but really doesn't support why you wouldn't want more hp and torque out of these motors. But I see no reason the horsepower output should be less on the UTV. My Z1000 bike puts out 130hp and around 70ftlbs at the wheel.  Yes I can see lowering a cam profile to have a little more torque and less HP but that is the beauty of a CVT clutch, you really don't need a lot of torque if you are clutched to run in the right rpm range. there are plenty of snowmobiles that tow stuff and can run in a relatively low rpm range cruising then at WOT tach up and scream. I really don't see a reason why these are dogged out. snowmobile motors are around the same operating rpms as the UTV's

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Offline chuddly

Re: Why so little HP
« Reply #6 on: July 12, 2017, 10:24:19 AM »
Snowmobiles are mostly 2 stroke and that normally requires being rebuilt more often.  Your talking apples to oranges.  People want reliable, hard working and high HP and cheap.  That is a VERY hard if not impossible thing to have all of those in one package.  and what a sled can tow vs what a 4wd UTV can tow are VASTLY different things.  Having pulled around a boat and trailer that weighs EMPTY at about 5k lbs I know a sled would not do that.
I can imagine a world completely at peace.  A world where there are no weapons, no war, and no violence at all.  And I can imagine us taking over that world because they would never expect it.

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Offline REDRIDER

Re: Why so little HP
« Reply #7 on: July 12, 2017, 10:55:32 AM »
Snowmobiles are mostly 2 stroke and that normally requires being rebuilt more often.  Your talking apples to oranges.  People want reliable, hard working and high HP and cheap.  That is a VERY hard if not impossible thing to have all of those in one package.  and what a sled can tow vs what a 4wd UTV can tow are VASTLY different things.  Having pulled around a boat and trailer that weighs EMPTY at about 5k lbs I know a sled would not do that.
they make plenty of 4 stroke snowmobiles now that make just about as much as the 2 strokes. No they won't tow what a UTV will but mostly because they don't have the weight/traction in the snow plus there is more friction towing on snow than on wheels. My zforce says the tow capacity is 1500lbs. look at the KTM super duke 1490 vtwin, monsterous torque and they are plenty reliable. The only thing I can think of is they keep the power reduced so they don't break axles and maybe the transfer cases as easily, otherwise there is no real reason, the technology is there.

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Offline willpower719

Re: Why so little HP
« Reply #8 on: July 12, 2017, 02:10:57 PM »
My 2 cents. The more power you squeeze out of any engine the more you lower the reliability. Generally all manufactures want to keep reliability high. Good mix between the two....and that normally means lower HP numbers.
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Offline REDRIDER

Re: Why so little HP
« Reply #9 on: July 12, 2017, 02:45:24 PM »
My 2 cents. The more power you squeeze out of any engine the more you lower the reliability. Generally all manufactures want to keep reliability high. Good mix between the two....and that normally means lower HP numbers.
A lot of people seem to see it this way. I disagree, to a point. I agree that getting power of an engine via compression ratio the higher compression the less leeway you have. These are already calling for 93 octane though. Other than that power comes from efficiency that comes with fine tuning fuel ratios and making good designs in things like the combustion chamber and good flowing ports and intakes. I haven't even looked but are these Hemi spherical heads? If so you can up the compression quite a bit before worrying about detonation especially running 93 octane which they are calling for. With a CVT clutch it is much easier to pull HP numbers since you really don't have to worry about low RPM torque, whats the lowest RPM when you whack the throttle, bumps you right to what 4500rpm stock? I hit over 5k when I hit the throttle with it clutched.  I'm just a little baffled on these things. I mean the snowmobiles are designed for longevity too they put thousands of miles on them the same they do with the UTVs.

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Offline doug80638

Re: Why so little HP
« Reply #10 on: July 13, 2017, 06:56:12 AM »
I don't know where the 93 octane requirement is coming from that you mention, but my 2017 Z800 uses 87 octane regular unleaded fuel.

As for horsepower, Chuddly has it right.

You can't compare the design requirements of a bike or sled with that of an ATV. The first two are designed to push relatively lightweight machines at sustained high speeds with very few mechanicals in between the engine and the ground. Higher RPMs will produce more HP but the torque band sits higher in the RPM range as a result, which is not a problem for these types of machines.

ATVs are not designed for sustained high speed use, but for a varied workload and to work harder at lower RPMs, requiring more torque at lower RPMs.

You could design a faster/stronger ATV with equivalent HP, but the cost to update the driveline to support the increased moment forces and still have adequate torque at the low end would drive the cost of the unit up. The risk to the operator also increases as the safety limits shrink.

The comparison with the z1000 is apples and oranges. It delivers its torque at 2K rpms higher, precisely because of the higher horsepower.  That's not what you need in an ATV.

If you want more horsepower and good torque at lower RPMs, then the answer is increased engine combustion volume.



« Last Edit: July 13, 2017, 08:18:27 AM by doug80638 »
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Offline REDRIDER

Re: Why so little HP
« Reply #11 on: July 13, 2017, 08:05:41 AM »
the manual we have a pdf online says "Recommended Fuel The recommended fuel for this vehicle is #93 unleaded gasoline."
It is not clear whether they are talking about a RON which I don't think they are because those usually start at about 97 and go up octane I think in Europe which is the RON, I assume they are talking about the AKI octane rating which is an average of the RON and MON number. 
« Last Edit: July 13, 2017, 08:11:32 AM by REDRIDER »

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Offline doug80638

Re: Why so little HP
« Reply #12 on: July 13, 2017, 08:23:59 AM »

From the service manual:

"Fuel type and Octane No. RQ-93 or higher unleaded gasoline"

RQ-93 is not 93 octane in the states. It's 87 octane here.
 
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Offline G19

Re: Why so little HP
« Reply #13 on: July 13, 2017, 08:51:56 AM »
I don't think these machines could handle any more HP.
The type of trail riding that most do require TORQUE not HP. You will need lower end torque to climb hills and go thru mud. HP is generally for top end or speed.
Comparing a 2 stroke sled to an UTV is unfair. 2 strokes run at incredibly high RPM and give higher horsepower. They do require rebuilding at various intervals depending on how hard they are run.

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Offline REDRIDER

Re: Why so little HP
« Reply #14 on: July 13, 2017, 09:08:52 AM »
I don't think these machines could handle any more HP.
The type of trail riding that most do require TORQUE not HP. You will need lower end torque to climb hills and go thru mud. HP is generally for top end or speed.
Comparing a 2 stroke sled to an UTV is unfair. 2 strokes run at incredibly high RPM and give higher horsepower. They do require rebuilding at various intervals depending on how hard they are run.
The max torque is at 6,000 rpm and the max HP is 6,700 rpm, again with a CVT clutch you can tune it to engage and run at specific RPM ranges to use the HP. I am not comparing these to a 2 stroke snowmobile I am comparing the to 4 stroke snowmobiles. about 50% of the snowmobiles made now are 4 stroke.
You can certainly use horsepower to go through the mud, if your max torque hits at 3k rpm and your max HP hits at 6k rpm and your CVT is engaged at 6k RPM you are using the HP, be it in mud, climbing a hill, or racing down the road. It is the same idea as using a high stall torque converter in a race car or pulling truck. You may think the truck is using it's torque to pull a load down the track, but when it's torque converter is fully engaged at 5k RPM it's past it's torque curve already.