Power to Weight Ratio: Four Stoke vs. Two Stroke

[retiredpop]

Can I ask a Stupid question Why cant we just ride what we want to ride and not worry about trying to explain that our sled is better than his sled????? I ride what I want to ride and I don't care what anybody else on this whole forum thinks about it and bashing me or my sled saying yours is better is Never going to change my mind!!! Sorry I'm not in the 8th grade anymore!! Just my 2 cents

Where's the entertainment value in that?

 

[christopher]

Can I ask a Stupid question Why cant we just ride what we want to ride and not worry about trying to explain that our sled is better than his sled????? I ride what I want to ride and I don't care what anybody else on this whole forum thinks about it and bashing me or my sled saying yours is better is Never going to change my mind!!! Sorry I'm not in the 8th grade anymore!! Just my 2 cents

It IS possible to have an honest discussion WITHOUT bashing.
If you have taken the time to read this long thread you will see there have been PLENTY of pro comments on both sides of the discussion.
The goal here is to dispel some of the old myths and look at the reality of a changing evolving situation.

 

[BigFish BC]

Can I ask a Stupid question Why cant we just ride what we want to ride and not worry about trying to explain that our sled is better than his sled????? I ride what I want to ride and I don't care what anybody else on this whole forum thinks about it and bashing me or my sled saying yours is better is Never going to change my mind!!! Sorry I'm not in the 8th grade anymore!! Just my 2 cents

because you cant fix stupid &as you can see there is a whole bunch of it in this thread.some people have to bash others to make themselfs feel better about what they think is right & wrong.there is no right or wrong just what works & fits for you.

 

[capulin overdrive]

Has to be turbo, but if I add my fat self into the power to weight equation.


Turbo 4stroke beats 2stroke, even turbo 2 stroke!


Stock 180 turbo 4 stroke beats 150 NA 2stroke.


270 4stroke beats 240 2stroke.

 

[Jaynelson]

They have come a long way with emissions control on vehicles. Not only is it emissions a vehicle is producing but it is also how quickly they come to life after a cold start.

I ran a new Mustang on an emissions machine just to see what it would do. Within 30 seconds of a cold start the machine was reading straight zeros across the board.

Yup, many newer auto engines produce fewer pollutants per unit of volume than the air in a large city contains. Modern gasoline auto engines really are that good for emissions. Any type of recreational equipment/vehicle isn't even on the same planet as far as tech goes.

 

[CatRpillar]

Has to be turbo, but if I add my fat self into the power to weight equation.


Turbo 4stroke beats 2stroke, even turbo 2 stroke!


Stock 180 turbo 4 stroke beats 150 NA 2stroke.


270 4stroke beats 240 2stroke.

You mean we have to include rider weight too? Is that with a half tank of gas and including brake fluid or no oil but including having my grip heaters on?

If I put my sled in reverse it feels lighter too.

 

[sidehil]

This will be my first sled with a reverse now that's an upgrade!

 

[mountainhorse]

Christopher... nice post... I'm interested in the sources and the dates for these charts you have posted.
Especially the last 3 charts.

Is this for current MY sleds or an average? (Like all the sleds visiting Yellowstone in a given year?)

Some of it seems outdated... but I could be wrong.

While the Skidoo with it's direct injection is pretty good for a 2s, the emissions created by the Polaris is much higher. The Cat is even worse. The Cat is only getting away with its emissions because of how much better the four strokes are in the lineup whose credits offset the 800.

The next MAJOR tightening of emissions is going to hit in 2017.
The pressure on the 2 Smokes is getting harder and harder.
Eventually the 2 Smokes ARE going to be a thing of the past.
The only question is WHEN....

 

[mountainhorse]

While the Skidoo with it's direct injection is pretty good for a 2s,
the emissions created by the Polaris is much higher.
The Cat is even worse. The Cat is only getting away with its emissions because of how much better
the four strokes are in the lineup whose credits offset the 800.

Do you have actual numbers for these from current MY Sleds from these mfgs.

I know that the 4S will be the lowest... that is a given... but curious to see the actual numbers for current MY sleds.



.

 

[geo]

If we talk EPA targets and futures.

Are the turbo kits installed by most Yam owners environmentally friendly? Meet EPA requirements? Could Yamaha meet EPA targets if the testing was done including % of units sold with dealer installed turbos? Is this even legal (being as I heard Yamaha endorses it and provides full warranty, could be wrong though) officially?

In reverse, could the other brands offer a reflash after sled is sold to give more power and longer living 2 stroke motor parameters and still be legal with EPA targets? Is it all based on a honour system or is there some other checks and balances?

As to the original thread topic, I wish everyone but me had to have a Yamaha Viper or it's Cat equal.

 

[mountainhorse]

Geo brings up a good point.

Is there any official emissions information on the turbo kit equipped Vipers?

Is there a certification for this?

As a stock Viper, how does it compare to other brands top offerings in the same track length?



.

 

[CatRpillar]

According to Yamaha releases the turbos are EPA compliant.

 

[mountainhorse]

Any links on that intel?


.

 

[CatRpillar]

Google - EPA Yamaha Viper - and you will find numerous. They all look like they took it from the same root document. I haven't found that specific source yet.

Doesn't surprise me though as except for NOx four strokes are way better than two strokes and adding a turbo shouldn't make a 4s worse than a 2s DI motor by a long shot. Lots of compliant turbos in cars these days.

 

[av8er]

Sure the oemm's might be required to meet these minimums

but how many people there crappy stock oem exhaust on a sled in the 1st place , I know I never have and never will.

 

[CatRpillar]

The announcement about the turbos being EPA compliant was from a Yamaha press release of Sept 15

 

[m1kflyingtiger]

But that is just the MPI 180 kit with not upgrades and dealer installed with dealer installed tuning. Any increased boost, lightweight muffler or manifold, different fuel controller, ect... And you no longer have a EPA tested compliant sled.

 

[christopher]

If we talk EPA targets and futures.

Are the turbo kits installed by most Yam owners environmentally friendly? Meet EPA requirements? Could Yamaha meet EPA targets if the testing was done including % of units sold with dealer installed turbos? Is this even legal (being as I heard Yamaha endorses it and provides full warranty, could be wrong though) officially?.

YES!
That was the point of all the testing they did last season.

 

[TRUEBLUEMAX]

I think the EPA takes it's time getting after aftermarket suppliers. I know with trucks and cars the removal of emissions devices is where the trouble really starts. For example all of the tuners selling diesel dpf delete kits really got the hammer brought down on themselves. Many went out of business because of it.

Seeing as how there really aren't emissions devices on sleds YET I don't see them coming after aftermarket suppliers. Were the manufacturers to do something I bet that would be a different story.


Sent from my iPhone using Tapatalk

 

[CatRpillar]

But that is just the MPI 180 kit with not upgrades and dealer installed with dealer installed tuning. Any increased boost, lightweight muffler or manifold, different fuel controller, ect... And you no longer have a EPA tested compliant sled.

Yes, but that's standard for just about any acceptance testing for any internal combustion engine since the 1970's. Remember when they started sealing off jet adjustments in carburetors.......