09 Apex

[QCRider]

I feel I should share some information that seems to have been missed here. The ONLY reason Yamaha chose to add the gear reduction was CLUTCHING!! Centrigual clutches lose efficency rapidly at higher RPM's. The gear ratio was chosen to keep the standard Yamaha primary in ot's sweet zone. This is reliable informationrelated to me by a dealer friend, immediately after being at Tech school for 03.

Dave

Dave, you're right about that. They knew they needed gear reduction if they used the R1 motor in a sled. It was the CHEAP and FAST way to get 4 strokes into production for snowmobiling and they were absolutely right to do it. Now they are developing motors specifically for sleds, and the next one will be the R1 replacement in my opinion.

 

[QCRider]

One more thing Tork. F1 doesn't use Boost because the rules prohibit it. That should tell you something. They would MUCH rather turbo charge the engine than spin it at 19,000 rpms, but they aren't allowed to.

 

[Tork]

Motorcycles and F1 cars don't have gear reduction???

I didn't say that they don't have gear reduction. I said that they are not exposed to the same type of stress that a snowmobile engine is.

By the way, you wouldn't want an F1 motor in your sled any more than a dragster motor. It might last a couple of hours longer, but not enough to matter. They run them for 2 races now, and that was a BIG deal to F1 when they changed to that.

Now in the first part you say that Formula 1 engines arent stressed the way a snowmobile engine is. Then in the second part you say that they last hours (two races worth) which would imply that they are stressed more than a sled engine. Which is it??
And yes I would like an F1 engine much more than a Top Fuel dragster engine if those were my choices for a sled motor. Keep that F1 motor below 15K RPM and it would last a long time.

I have not seen one valid point why gear reduction is a bad thing.

 

[**sj**]

I feel I should share some information that seems to have been missed here. The ONLY reason Yamaha chose to add the gear reduction was CLUTCHING!! Centrigual clutches lose efficency rapidly at higher RPM's. The gear ratio was chosen to keep the standard Yamaha primary in ot's sweet zone. This is reliable informationrelated to me by a dealer friend, immediately after being at Tech school for 03.

Dave

they chose this because they didnt want to invest time to clutch effectively....again...this would have been a good choice for a narrow torque band motor like all two strokes exhibit....the meat of the band on the best of two strokes lasts 1500 rpm's max ?

look at the torque of this motor...it could run and drive actually engage at around 2000 rpms (with nice torque) without a driven spring with a light enough weight and have spun easily to it's peak with a way broader range...better efficiency...instead they choke down the motor with the reduction unit (losing power) and end up throwing 72 grams of weight!

look at the profile of the weight....it describes the torque

I'd be willing to lay down coin on the above ,Yamaha just did what was cheaper....

 

[gsxr]

What about a sprague clutch for engagement .( like a atv )

Direct drive , no reduction ,
and spin the motor , at 13000 rpm ,

Think about that !!!

 

[NyTrOMaNIaC]

3rd gen R1 engine with 180ish HP will be in a Yamaha sled for 09, history proves it, you wait and see !

 

[Tork]

3rd gen R1 engine with 180ish HP will be in a Yamaha sled for 09, history proves it, you wait and see !

Yeah, but it makes that big power by spinning 2500 RPM faster than the current Apex motor. Like I said, nothing wrong with gear reduction, and it would be more even more important in this case. From a cost standpoint it makes sense, all the parts are right there in the parts buns to do it. I mean the only way Yamaha can build 4 stroke sleds for about the same price as the others build 2 strokes, is to keep the sled motors somewhat similar to what they have in their bike and watercraft engines (share some of the parts and manufacturing tooling). However Yamaha wanting a sled motor that spins at 13K RPM remains to be seen.

What blows my mind on the new R1 is the variable velocity stacks. It would be cool to have those sticking through your sled hood and watch em change length at about 10K RPM.and then listen to the motor start to trumpet up to its nearly 14,000 RPM redline

If they stay with a 4 cylinder, my guess for 09 Apex would be that they would stay with the same delta box castings, but go with the super strong beveled tunnel and the nytro spherical rod end bearing front suspension.

Here is the variable length velocity stack intake of the R1

 

[**sj**]

What about a sprague clutch for engagement .( like a atv )

Direct drive , no reduction ,
and spin the motor , at 13000 rpm ,

Think about that !!!

there ya go...exactly....it's in the torque curve fella's...there's a lot more performance in the existing 150 motor..

 

[Tork]

Apex motor with current displacement and RPM has a potential of 160 HP (all equations based on natural aspiration)
That might require the 4 valve head of the new R1 and some of it's better breathing tricks. *very cost effective, parts, technology and machine tools already in place for 160 HP
(15HP x .998 thousand CC x 10.7 thousand RPM = 160 HP)

Now they have crossed the magical 1000 cc barrier with the new Nytro.
So go 2 MM bigger bore and Apex becomes 1052 CC
Now we have a potential of 169 HP
*Very cost effective. tooling and many of the parts already in place because of the 1052 cc watercraft motor. (15x 1.052 x 10.7 = 169 HP)

Now take advantage of the better breathing in the first paragraph and you already have a motor that can make power at at least 500 RPM higher.
So now we are at 176.7 HP 15 X 1.052 x 11.2 thousand RPM = 176.7
And it would cost practically nothing (over the current Apex) because everything is already there in their parts bins to do it, and the tooling is already in place.

So the 176 HP 1052 09 Apex is what I want and it doesnt require anything that they dont already have at their finger tips.
Add the Nytro A arms and spindles, the rivited beveled nytro tunnel and I'd prolly be able to buy it discounted for under $10,000 : )

 

[danq]

I didn't see anyone mention the possibility of a 4 cyl nytro style motor in the apex? If you get 138 hp out of the new 3 cyl, you could get 184 out of a new 4 cyl version. All that and no gear reduction...

I don't need that much HP. I rather have the fuel mileage of the current vector with the power and fuel injection of the new nytro, in the DB2 chassis..

 

[Tork]

I didn't see anyone mention the possibility of a 4 cyl nytro style motor in the apex? If you get 138 hp out of the new 3 cyl, you could get 184 out of a new 4 cyl version. All that and no gear reduction...

I don't need that much HP. I rather have the fuel mileage of the current vector with the power and fuel injection of the new nytro, in the DB2 chassis..

That is not out of the question either. The Vector motor which was the basis for the new Nytro motor is basically 3/4ths of the FJR 1300 motorcycle motor. They could easilly produce this, as the basis of a 4 cylinder Nytro motor is already there. But would they build a 1300-1400 CC sled motor? That is what it would take to get 165+ HP out of a motor that spins at 8600 RPM

(15HP x 1.3 thousand cc x 8.6 thousand RPM = 167.7 HP)

Actually adding a 4th cylinder to the 1052 Nytro motor works out to 1400 cc
(15HP x 1.4 x 8.6 = 180 HP)