some 09 stuff from yami site KINDA

[apltx08]

Are you guys saying you would seriously prefer an 1000CC 4 cyl with 170 hp and 90 lbs of torque vs an 1350 Triple with 170HP and 120 lbs of torque at probably the same weight?

Torque is what moves sleds in the snow. You have to try an nytro on the trail it makes over 90 lbs at typical trail RPM, it's an awesome trail engine, an 1350 triple would be even better! The Nytro engine doesn't sound too shabby either.

No, I 'd buy a 4 holer over a 3 holer anytime!!! that 4 holer FEELING is just CRAZY!

The other thing YAM better consider is INSURANCE company's will not like these BIG "cc" numbers, I had 2 insurance brokers refusing to insure sleds with "cc" over 800 and 1000...you better have deep pockets to insure anything over 1000cc...

 

[Laban]

Are you guys saying you would seriously prefer an 1000CC 4 cyl with 170 hp and 90 lbs of torque vs an 1350 Triple with 170HP and 120 lbs of torque at probably the same weight?

Yes.

Torque is what moves sleds in the snow.

No. Torque + rpm is what moves sleds in the snow. Let's see now, what's that called.. ah, horsepower..

Low-end power (what most people call torque, even though it's wrong) is highly overrated in snowmobiles because of the CVT type of transmission. IMO, Yamaha should build smaller (=lighter) engines and sacrifice the low-end power for a stronger high-end. You don't need any power at 2000 rpm if the clutch engages at 4000 rpm. You'd prefer a broader high-end though but that's a completely different thing.

 

[QCRider]

No. Torque + rpm is what moves sleds in the snow. Let's see now, what's that called.. ah, horsepower..

Low-end power (what most people call torque, even though it's wrong) is highly overrated in snowmobiles because of the CVT type of transmission. IMO, Yamaha should build smaller (=lighter) engines and sacrifice the low-end power for a stronger high-end. You don't need any power at 2000 rpm if the clutch engages at 4000 rpm. You'd prefer a broader high-end though but that's a completely different thing.

Have you ever raced a 120 hp Vector and a 145 hp RX-1? I have run 2 different RX-1s and two different Vectors several times with the same result. The Vector is surprisingly close to the RX-1 up to 90 mph. Beyond this the RX-1 S-L-O-W-L-Y walks away. This with a 25hp difference at basically the same weight.

Morrisond's statement was two motors at 170hp, one with more torque. So why are you bringing up horsepower at all? HP being equal, I would always take the motor with more torque.

 

[Laban]

Morrisond's statement was two motors at 170hp, one with more torque. So why are you bringing up horsepower at all? HP being equal, I would always take the motor with more torque.

I'm bringing up horsepower because that's what really matters.

And i'd rather take the motor with a broader powerband (where it matters) then the one with the highest maximum torque. And with a snowmobile, power below 4000 rpm isn't that relevant.

So, as i said, what i want Yamaha to do is to forget about the lowend, there's CVT instead of a gearbox on a snowmobile so why not use that fact to your advantage. A small , high-revving engine with lots of power on the high-end, nothing below 3000-4000 rpm . Let's say Phazer triple, 750 cc, 140+ hp. Would probably save close to 20 lbs from the current Nytro engine.

Unfortunetly, the really really stupid WSPA rules means that gear reduction isn't allowed. That's not really what you would want if you like fourstrokes.

The Vector is surprisingly close to the RX-1 up to 90 mph. Beyond this the RX-1 S-L-O-W-L-Y walks away. This with a 25hp difference at basically the same weight.

Have you ever wondered why the Phazer seems to have a surprisingly good low-end but nothing on the top ? Is the Phazer engine a high-torque engine ?

 

[morrisond]

Laban, Have you tried an Nytro on an Trail?

It doesn't make max torque at 4,000 rpm or 2,000 rpm it makes it right around 6,000-7,000, i.e. trail rpm, you blip the throttle it just launches the sled off any bump. I have an Apex and an Attak as well and for trail riding I'll take the Nytro Motor any day. It takes the Attak an pregnant second to spool up, the Nytro is right there. I'll also take the Power pulse of an three over 4 cylinder engine any day, it's more tractable.

Are you saying Torque doesn't matter? Where torque really matters is in the Snow, say Climbing an Hill or in 8 inches of powder on an lake, you need the torque to be able to shift the clutches out more and go faster, it's one of the reasons an normally aspirated Apex can't break 100 MPH in powder on an lake, but an high torque motor can. Get an Apex on glare Ice, where there is less resistance and it flys.

 

[morrisond]

Morrisond's statement was two motors at 170hp, one with more torque. So why are you bringing up horsepower at all? HP being equal, I would always take the motor with more torque.

I'm bringing up horsepower because that's what really matters.

And i'd rather take the motor with a broader powerband (where it matters) then the one with the highest maximum torque. And with a snowmobile, power below 4000 rpm isn't that relevant.

So, as i said, what i want Yamaha to do is to forget about the lowend, there's CVT instead of a gearbox on a snowmobile so why not use that fact to your advantage. A small , high-revving engine with lots of power on the high-end, nothing below 3000-4000 rpm . Let's say Phazer triple, 750 cc, 140+ hp. Would probably save close to 20 lbs from the current Nytro engine.

Unfortunetly, the really really stupid WSPA rules means that gear reduction isn't allowed. That's not really what you would want if you like fourstrokes.

I think the problem with the Gear Reduced 750 is that you still wouldn't get enough Torque. As the 750 would be basically 3/4 of an Apex motor, you would be looking at max torque of about 70lbs. no where near what the Nytro Makes, it's worth the sacrifice in weight for the 94 lbs of torque.

You can Rev an 4 stroke higher to get more Horsepower, but unless you increase Displacement or Compression(which is difficult to do on pump gas) you ain't going to make more torque.

Even if the new Apex Motor does make 170Hp but is still an 1000CC 4 cylinder it's torque will still be around 90lbs. It will be faster on glare ice where the resistance is minimal but in snow it could be no faster.

Well the Turbo Kit Builders would be happy with this, as the Turbo's add significant Torque.

We have an 4 Stroke Venture and in the Snow it's not significantly slower than the Apex/Attak. It's an lot heavier, but it makes about the same amount of torque.

 

[Laban]

It doesn't make max torque at 4,000 rpm or 2,000 rpm it makes it right
Are you saying Torque doesn't matter?

Yes, i'm saying that Torque does not matter. What matter is horsepower. If you need it at 6000 rpm then you look at hp@6000rpm.

Might be a little bit aggressive here with nothing below 4000 rpm but it could definitely be a lot more aggressive then the current engines are.

The Nytro might be snappier then the Apex but you need to take clutching, gearing and such into consideration there also.

Well the Turbo Kit Builders would be happy with this, as the Turbo's add significant Torque.

You really meant hp here right ? (though it does of course add torque also since hp i= torque * RPM / 5252 if i'm not mistaken)

I think the problem with the Gear Reduced 750 is that you still wouldn't get enough Torque. As the 750 would be basically 3/4 of an Apex motor, you would be looking at max torque of about 70lbs. no where near what the Nytro Makes, it's worth the sacrifice in weight for the 94 lbs of torque.

So basically, you're saying that 140 hp at 9500 rpm is better then 140hp at 12000 rpm (lower torque) ?

If that's the case , why ?

You can Rev an 4 stroke higher to get more Horsepower, but unless you increase Displacement or Compression(which is difficult to do on pump gas) you ain't going to make more torque.

Who cares since it's hp you're after.

 

[QCRider]

Let's look at it another way. There are two ways to increase Horsepower:

1.) More Torque
2.) More RPM

How do you make more torque? Bigger displacement. Relatively inexpensive and simple.

How do you make more RPM? Complex and expensive engines. Special components, lightweight valve trains, crankshafts. More RPM means more gear reduction. More RPM means more stress on every component in the engine.

This is like comparing a Corvette ZR-1 to a Ferrari Enzo. Both make a lot of Horsepower in very different ways. Why do you suppose that the Corvette can be had for a fraction of the price of the Ferrari yet still run with it in nearly any environment? Because the Enzo is an exotic. Made of exotic components. While I would love a Ferrari snowmobile, I don't think it would sell particularly well. I'd rather have the Corvette.

 

[morrisond]

Under big loads(i.e. Snow) it takes an awful lot of torque to accelerate and move an snowmobile track.

If there isn't an lot of load, torque isn't as big an issue, and then HP matters. In snow torque matters, on glare Ice where your Biggest issue is Aero, HP wins.

Just ask yourself how fast an Diesel truck towing an 10,000 lb load would accelerate or go up an hill with 100lbs of torque versus 600lbs of torque but similar Horepower.

Do you seriously believe they would accelerate at the same rate, or be able to maintain the same speed? Goind up an Hill towing an load is an good analogy to going through the snow.

On an flat road the Diesel Truck with the same HP but less torque could maintain the same speed at the same RPM assuming there was no grade.

 

[Laban]

How do you make more RPM? Complex and expensive engines. Special components, lightweight valve trains, crankshafts. More RPM means more gear reduction. More RPM means more stress on every component in the engine.

It's true that more RPM means more stress on every component. On the other hand, an Apex engine can take around 500 hp (Turbo) without changing any baseparts in the engine. Standard crank and so forth. And it'll probably last 4-5 times longer then the chassi (std). Some people might argue that this is a good thing, some people might be of the opinion that it's a snowmobile, make it a little bit lighter instead. I can live with it if it only lasts twice as long as the chassi and can only handle 300 hp Turbo'd

Why do you suppose that the Corvette can be had for a fraction of the price of the Ferrari yet still run with it in nearly any environment?

Because the Corvette is a POS compared to the Ferrari ?

 

[Laban]

Just ask yourself how fast an Diesel truck towing an 10,000 lb load would accelerate or go up an hill with 100lbs of torque versus 600lbs of torque but similar Horepower.

Do you seriously believe they would accelerate at the same rate, or be able to maintain the same speed? Goind up an Hill towing an load is an good analogy to going through the snow.

It's funny that you ask this. Let's do a little excercise here:

1: F1 engine, 900 hp at 19 000 rpm
2: Truck engine, 500 hp at 3000 rpm

Transmission: CVT with an infinite amount of gears and that can handle an infinite amount of power. Nice eh ?

Which of these engines will be faster up a hill towing a standard load (for a truck) ? We'll assume that the F1 engine won't blowup here also

 

[QCRider]

It's true that more RPM means more stress on every component. On the other hand, an Apex engine can take around 500 hp (Turbo) without changing any baseparts in the engine. Standard crank and so forth. And it'll probably last 4-5 times longer then the chassi (std). Some people might argue that this is a good thing, some people might be of the opinion that it's a snowmobile, make it a little bit lighter instead. I can live with it if it only lasts twice as long as the chassi and can only handle 300 hp Turbo'd

So if this were easy, and this motor is capable of it then why has nobody taken the route of changing the reduction gears and spinning the motor up like a bike? Take it right up to 15,000 RPMs... Why would Yamaha have lowered the limit to where they did? Reliability.

Because the Corvette is a POS compared to the Ferrari ?

I dare say that the Ferrari has only it's name and looks on the Corvette. You could never drive it every day and get away with it. It would spend more time in the shop than on the road. The Vette could be an every day car and still race with the Ferrari any time.

 

[Laban]

I dare say that the Ferrari has only it's name and looks on the Corvette.

You'd probably find a lot of people disagreeing with this

You could never drive it every day and get away with it. It would spend more time in the shop than on the road. The Vette could be an every day car and still race with the Ferrari any time.

I somehow doubt that the Vette would stand a chance against the Ferarri on a racing track. And it's of course not only how fast a car drives from A to B that's relevant, it's how it does it.

 

[morrisond]

Infinite Range CVT? This is where your assumption may be wrong. An snowmobile transmission is infinite between it's starting ratio and ending ratio. But it's does have an starting ratio and ending ratio. With more torque you can have an higher lower ratio(meaning less torque multiplication) to achieve the same rate of acceleration giving you more gear on top.

At 80 mph, the CVT just can't shift down enough to multiply the torque enough to compensate for an lack of, in an High RPM engine low torque, it doesn't have the range.

Your comparison of an 19,000 rpm 900 Hp F1 engine vs an 3,000 RPM 500 HP truck engine is not valid as they are not the same HP, the point many of us have been trying to make.

In F1 the old turbo motors of the 80's had much greater acceleration as they had more torque, but similar HP to today.

An modern analagy would be Lemans Racing. The Audi Diesel makes about 650hp and 800 lbs of Torque, absoultely crushing the F1 based racers that have similar HP but much lesser torque. Audi can run larger gears, giving up not that much in accel(limited by traction anyways - just like sleds) but still accelerating faster than the F1 based cars, but crushing them on top by I think 20MPH from an press release I read the other day.

 

[Laban]

So if this were easy, and this motor is capable of it then why has nobody taken the route of changing the reduction gears and spinning the motor up like a bike? Take it right up to 15,000 RPMs... Why would Yamaha have lowered the limit to where they did? Reliability.

There's two reasons imo, the first is that Yamaha has no competition in the high-end fourstroke market for snowmobiles. And thus, they can get away with using technology from 2001 (R1) in 2008 snowmobiles. The second is that making the engines more specialized for snowmobile purposes will cost a bit more (initially) since they can't reuse as much as they do now from their bikes.

I'm thinking that some additional fourstroke competition from AC or Ski-Doo could change this though. I'd also definitely like to see what they would do if it the wspsa rules also allowed 750cc triples with gear reduction.