I heard a rumour of Polaris working on DI technology for 2010 or possible 2012
If this is true it would be great for Polaris Industries, and might spell trouble for
Yamaha and it's heavy four strokes.

I should sincerely hope and assume Poo is working on it, Cat too. If they're not, they're gonna hurt real bad a couple years from now if they intend to be competitve with their 2 stroke engines. After all, Doo already has their new DI out for purchase across their entire lineup, and they have declared their SDI system to be fully discountinued and obsolete. So Polaris and Cat need to play catchup now in that department. I believe DI will be the only way for a 2 stroke to meet emmissions requirements in the not-too-distant future.

Even with DI, a 2 stroke will still be dirtier than a 4 stroke from an emmissions standpoint. So depending on how the future EPA mandates are written, I certainly don't see any impending death of the 4 stroke in the forseeable future. Whether clean DI is available in all 2 strokes or not, I believe 4 strokes will continue to expand and improve across all 4 brands, probably faster than they ever have. Even this year Cat has introduced a new 4 stroke turbo musclesled, and Doo is even abandoning their all-2-stroke-philosophy and offering the lightest 4 stroke performance sled on the market as a new model. I would suspect Polaris is working on improving or replacing that 4 stroke as well, as the FST setup is starting to get a bit old. And you KNOW that Yamaha is working hard on their future motors, which are always stellar.

The 4 stroke is far from a dying breed...

The main reasons for people to go to 4 stroke were/are fuel economy, no smell and improved reliability. If Doo's e-tec successfully adresses these concerns it might very well stem the tide of 4-s buyers...only time will tell.
The hyper sled market is one were the 4-stroke will eventually rule (Cat is there now) as no 2-s will compete with a turbo 4-s, and this is one segment where weight is not a big priority. Look for Doo to add some kind of pressure to their 1200 as they have dropped the 1000SDI, and will need to compete with Cat on the lake.

Good post. IMO, Polaris had better get on the ball with better performing, cleaner, much more efficient two strokes. It seems the CFI isn't really sophisticated enough (?). It's kinda like a half-assed fuel injection system. Better than a carb, but not what I would expect from a computer controlled fuel injection system. I was getting a best of 10 MPG with my CFI. Not really impressive. It did run ok, but I could do near the same with a carbed engine. With fuel prices going higher all the time, the next generation of 2-stroke engines need to get near 20 mpg, with good drivability and low emmissions.







I wonder how far away from a production two-stroke turbo sled we are?????????????????? Hmmmmmmmmmmmm............

It looks like it would be tough to mod a DI motor.
I won't drive a stock sled.

I am not defending Polaris and their CFI motors as I once believed and then shown where they stuck it. But to say there not sophisticated enough is not correct. CFI system is very technical and sophisticated and should have been the best to every hit a 2-stroke snowmobile. Now the problems are with quality, and cheap items giving either false or to temperamental reading resulting is inconstant and poor performance. Either poor mpg, lack of punch or just doesn't run is a direct result of "crap in is crap out"!

If all the issues with the CFI Polaris had were related to "cheap" sensors and the like, then shame on Poo.
One of the reasons I said it seemed like the CFI wasn't sophisticated enough is the situation with the 08 longtrack 800's vs the never-released 121 inchers. The mountain guys (for the most part) didn't have too many problems with the bog at steady throttle, but the same sled would be much more prone to it at lower altitudes. I figured the CFI couldn't make the right corrections for the lower altitude...??? I know it SHOULD be able to, but what the heck? Any auto EFI system would work at these different altitudes, so why can't the CFI?? Just seemed like the CFI computer did not have enough info to run correctly at all the different conditions. Guess it may not have the CORRECT info??
I am a fan of EFI, don't get me wrong. My last sportbike was a fuelie, and it ran just plain awesome. I wasn't completely disappointed in the CFI on my Fusion, just wasn't "wowed" either. It did at times have a dead spot after being run hard, shut off and then ridden again at lower engine rpm's. Thsi would go away after a couple minutes of riding, but could be duplicated easily. Also, the 10 mpg's wasn't overly impressive either.

I am awaiting to see what Polaris has for 2010 (rumored). No new sleds for me until I'm sure the whole CFI/EFI/DFI deal gets figured out.

I think that CFI was a good step forward on sleds, but realistically, it's not very sophisticated. It appears that it is basically a table driven system controlled mostly by static inputs like throttle position and rpm. Sure it does something with altitude and temp or maybe it just used barometric pressure for both, I don't know. But a more advanced system would have some form of closed loop feedback from either precise pipe temp or even better an O2 sensor. I know that there is a pipe sensor, but I've read that it's used basically as a hot / cold sensor, not really an indication of real-time air/fuel ratio, that's what an advanced system needs. I'm sure that better systems are in the works, and for now, I think that they are doing okay. But, Polaris does not seem to be in the lead in this area of R&D, I hate to admit it but with the better mileage on the old Doo 600SDI and now the ETEC DI, Doo seems to have the lead in 2 Stroke injection systems. Flame away if you want, I still prefer Polaris sleds, but I'm not afraid to give credit where it's due.

I agree, and that's exactly why I'm waiting to see where all this ends up before buying another new sled. I'm sure the fuel injections systems will become quite good, giving low emmissions, great power and mpg's..... but they're not at that point...yet.

Do a little research...
Polaris bought into a group a couple of years ago..
Look for something call Ortibal Injection,( direct injected along with air..)

DI for 2010, a little inside info there. i dont knwo if it goign to be on every motor but it will be on some.

They've had it along time, and they should have been using it. I have a MSX 140 Direct injection watercraft ( Yes martha he said direct injection!)1200 tripple D.I. It works flawless, great fuel and oil consumtion. I also have a 98 SLXH with a 1050 , I will fill the slxh three times before I even think about topping it up. I bought my 05 thinking it would have they same type of tech( not direct but semi and would be close) They had no prob putting the MSX 150 mill into the IQ, they should have put a tripple D.I in.

That goes back to BRP getting control of OMC. Polaris had their hand in Ficht Gbmh I believe at the time.
BRP is all over Orbital and the spin-off company / partnership with Siemens, Synerject. I don't think Polaris is down that road.

I am sure Polaris learned alot of stuff over the last few years with their various European partnerships.

There is no doubt there will be a GDI system for 2010, they have to.

Please top ski-doo and go with a 800 DI 136 switchback at 480lbs. I was at the 09 snowmobile show and talked with one of the polaris guy ( give away shift talker) he said big changes in polaris for 2010. He also said (not when) but polaris will have to go with some sort of DI or end up with 4 stroke motor to meet EPA standards in the near future.

I can't wait for 2010 I have been excited about the 2010 for months .

Polaris used Ficht in their watercraft and actualy had a better time with it then OMC, then BRP bought OMC/Ficht and then Polaris was done with watercraft. Polaris is currently working with Orbital DI on an ATV for the military that will be able to run on multiple types of fuel. So the relationship is there, but will it make it to sleds? Anyways, if the EPA gets to strict, not even DI will pass.

Beyound the fuel injection, crank trigger ignition systems that drive these things, I think the mechanical design of the motors is also needed to be revised. I really don't have much faith in liberty producing outstanding products. I wish Polaris and Honda would just join forces and have their own spin off company.

I hate using yammi as an example but they are out of two strokes for ever. they run some serious compression in the detuned R1 motor with needle/roller bearings and still manage 150HP on 87 octane. You can do soooo much more with head design, runner, intake port, etc on a 4 stroke than a 2 stroke even if it is DI with air assist.

My point here is by continuing to mess around with 2 strokes, we are only wasting valuable time on 4 stroke technology. Then by the time the EPA kills all two strokes, we will be too far behind the 8ball to compete.

So my point is this, becuase of the massive torque the 4 strokes make, (yammi nytro is a good example of big torque in a 130 motor) they always will get the holeshots in drag races and snoX. It takes a 2 stroke with about 15 more horse to compete. For example, I gaurentee you the 800 dragon that comes out will still not run down apexs. Maybe on this board and other bench racing, but not in real life. It would take 165 2 stroke horse to handle the yammi power band. Is the FST able to run with it??? I only ask because that is the current platform to build on right now.

Guys I am not arguing - I am only adding to this conversation with valid points. I love polaris and will always, just want my team to be the best is all.

I think you are forgetting the displacement advantage the four strokes are being handed in all forms of racing. As much as I liked my 05 fusion 900 and my current 06 900 they both handle like crap compared to the 06 fusion 600s I ride with on tight slower trails considering the main difference is the forty pounds under the hood. I dont care how much they lighten the chassis its hard to balance the extra engine weight sitting in the front, especially for 140 pound riders like me. If they can make a light reliable 2 stroke pass emissions I think it will always out perform the 4 strokes in the trails and I dont really care if the engine last over 7000 miles because the chassis is usually shot by then if ridden hard.

Have to disagree with some of what you said. First, when you talk 2-stroke, you seem to have the idea of a "traditional" sled motor stuck in your head. In those terms, yes, 2-strokes won't be around forever. However, by definition, a 2-stroke is simply a motor that fires it's cylinders every 2nd stroke, not every 4th one. With the advent of practical DI technology and all the electronic controls that go with it, I suspect we will see 2-stroke motors ending up in automobiles, both in diesel and gasoline versions. Not 2-strokes as you think of them, but 2-strokes regardless. The advantage 2-strokes have for automotive applications is the same as for recreational vehicles - light weight, high HP, small package. There is even research going on exploring the possibility of doing "displacement on demand" engines by switching between 2-stroke and 4-stroke operation. Rather than simply shutting off cylinders, build a smaller motor and fire the cylinders twice as often when needed. It won't be the recreational vehicle industry that drives this, but rather the auto industry. With the concerns over fuel economy and emissions, these ideas are going to become reality because a 2-stroke motor has real, practical advantages over 4-strokes. I really feel both 2-strokes and 4-strokes will be undergoing changes in the future. Current 4-strokes will be having some of the same EPA issues to deal with as 2-strokes will. Thinking that 4-strokes are further ahead is a "perception", not necessarily a reality.

Ya. Me too, I started my countdown for 2010 the end of last summer. I can't believe some of the things they have came up with.

Please Enlighten us with your inside info.............

I don't have a good feeling that Polaris will have DI working correctly by 2010. Based on their past history, they will rush out the product just to head off competition leaving us consumers to test. Remember these CFI motors have been around for some time. 700 motors were tested a whole two years before release to production. My 07 never ran good and the issues were the same that Polaris had back when tested a year before. I would love to see Polaris figure out these issues because the IQ chassis is the best chassis to ever hit the snow. EPA restrictions are hurting these manufactures but this is no excuse for first year teething issues that most here accept as normal. 2 strokes are just as clean as 4 strokes and if you chart out the better SDI motors, you will find less expensive to have. Sure 4 strokes will run 10,000 miles but most don't have them that long. We as consumers lost big time when WSPA ok the 3/4 rule giving the 4 strokes larger displacement advantage. CC for CC will give us consumers either a light as 2-stroke sled or one less race team.

I do believe that the new E-tech engine is as clean or cleaner than Yammis four strokes-
Also, As Weantright mentioned an engine that can run 10000 miles is only as good as the chassis that it's in, Secondary parts like clutches, bearings, tracks, shocks will wear at the same or greater rate due to the extra weight so if the DI engines can produce 20 miles per gallon with lean oil usage an can be reliable for 5000 miles without engine teardown, the benifits of the two stroke engine will still be there IMO.

I'm no engineer, but I doubt that current style 2-strokes have a chance against available 4-stroke technology emissions wise - regardless of the advances available with Direct Injection. The problem that I see is the expansion chamber exhaust design which uses reversion to recycle the exhaust, by drawing it back into the combustion chamber. This style of exhaust must be extremely difficult to control what gets out the exhaust, especially since it is tuned for a specific rpm and at any other engine speed is less efficient, consequently allowing unburned fuel and other harmfull emissions out the exhaust pipe, and that creates an emissions nightmare. While there could certainly be ways around this, it's hard to imagine that the small scale use of 2-stroke technology can keep pace with the widespread use and R&D dollars in 4-stroke technology courtesy of the automotive industry and to a lesser extend motorcyle, etc. industries.

I agree With Orville-X as we consumers do not know whats in the pipeline at the moment we forget the cleanest outboard RIGHT NOW is a 2 stroke Etec the leaner you make a 4 stroke you get other problems Thats why new regs for 4 stroke stearndrives that are comming are putting cat converters on them to pass. And why do you think all the makers of real power 4 Strokes the engine size is over 1000CCs (I know the Phazer is less but it is no better than a 2 stoke and still less power) you need air volume for a 4 stroke to GO If thats all you want to do is go over 100MPH all the time thats fine but I still think 75% of sledders still like a light fun sled not a lake rocket just my thoughts, Jx

Having the same cc and rpm 2 stroke and 4 stroke means the 2 stroke has the potential to do twice the work as a 4 stroke. Thus the huge power potential advantage to the 2 strokes.

A 600cc 2 stroke at 8000rpm and 100% volumetric effeciency (for easy math but not real world VE) displaces 4,800,000 cc of air.

A 600cc 4 stroke at 8000rpm and 100% VE (again for easy math) displaces 2,400,000 cc's of air.

For each cranshaft rotastion 2 combustion events per 1 combustion event is a huge advantage. Sure, the volumetric effeciency of a 4 stroke is better, but it would have to be twice as much as a 2 stroke to become even at the same rpm.

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Thoguth I'd throw that in. Most of us know the 2 cycle vs 4 cycle thing, but we tend to forget this part of it.

I'm not sure how so many people here have concluded that a DI motor is cleaner than a 4 stroke. Not by current EPA Normalized Emmission rate standards they're not...that's for sure.

Even in Doo's own advertising (which obviously should be slanted toward Doo), they make no such claim. They specifically state the EPA tags will read approx as follows:

Cat throttle body EFI: 7.7
Poo CFI: 5.4
Doo's new DI: 2.6
Yamaha carb'd 4 stroke: 2.5
Yamaha FI 4 stroke: 0 to 1.6 depending on model
Doo's new 4 stroke: 0

ALL the 4 strokes are tested to be cleaner than ALL 2 strokes...on snowmobiles...DI or not. At least according to the EPA...which is all that really matters. And since my boat almost ALWAYS gets stuck when the snow gets deep, I don't really care much about boat motor emmissions.

Now, when EPA changes their testing methods and requirements again? And as DI technology improves? And as 4 stroke technology improves? And as hydrogen powered snowmobile technology is developed? And as boats become more capable in the deep snow? Who knows? My crystal ball is in the shop or I'd tell ya...

Because of a better way to meter the fuel there is a leaner mixture in the pipe. This leaner mixture will be burnt at the next cycle resulting in less fuel adding into this cycle. The many sensors keep everything in line, it's a very narrow line. 2 strokes are cleaner than 4 strokes with one type of measured gas while the 4 stroke is cleaner with another. Either way as of 2012 Doo's SDI should pass EPA and have some room. 2 strokes will be around for some time and will be getting better. 4 strokes are here to stay but should lose performance and durability as time goes on, at least box stock wise.

All I was trying to say was 4 Strokes are not the end all they are only now SOME WHAT better than a 2 stroke in the smog area and that depends on the test done. Heck 4 years ago in allot of folks mind, 2 strokes were dead but they are still in the race They still have not made a closed loop 2 stroke that I know about yet, but most of the 4 strokes are. time will tell give me a 2 stroke 600CC 120 Hp light trail sled that we can move around and I think most folks will be happy. WHY does everyone want a heavy 4 stroke I can not fig it out, and do not tell me they last longer because most folks get rid of there sleds way before the motors are bad heck the track is bad before the motor is bad just my 2cents Jx

I demo rode the 600 etec mxz yesterday in Curtis, Mi. It is impressive . VERY crisp and clean on the throttle . idles very smoothly and accelerates very hard . I ride a 07 600 cfi and i was impressed. It's very quick revving engine. Snap the throttle and instantly to 8200. Lined my sled and the 600 on the hard packed snow lake . The mxz jumped a quick sled length on the start but from then on the distance never changed between us. Let off about 85 mph.My sled is bone stock, no studs, 1850 miles.

Do you need a tuned pipe for DI? If Polaris has patent rights to use Orbital, I would assume Orbital does the majority of the mapping for them. No different then Bosch with FI and Mikuni with carbs. I believe Orbital injects both fuel and air into the cylinder, with E-tech I beleve it is only fuel. Plus, if the ATV DI system can run on multiple fuels, they should be able to share this capability with the snowmobiles for different fuel blends. And, IMO pollutants should be imited by lessening the amount of fuel burned, vs just lowering the amount of those particular pollutants the EPA is looking for without concern for the amount of fuel burned.

A two stroke is a two stroke no matter how it gets it's fuel / air mixture so yes, you will still need the tuned pipe. I believe Polaris does all their own mapping and calibration for their Military ATV DI engine so they will likely be doing the same on the snowmobile engines.

Just noticed this thread and chuckled. Back in the late 70's I was part of a college team working on lab project to fit a 2 stroke Evinrude outboard with a Bosch mechanical fuel injection system. We succeded in getting it to run on par with the carbed prior to running out of time. Thirty years later and seems like so little has changed (excepting the whole emission awareness thing).

I would expect DI technology and 2 stroke diesel technology to converge. Thus the multifuel technologies. I'm minimally familiar with the Orbital technology, but I see that the path to Turbocharged two stroke. Can you say WOW? Major HP in a lightweight package. Primary issues become knock control and emission management. That could become much more manageable with electronics controlling volumes, pulse timing, pulse durations, injection pressures, etc.

As per post #12, Polaris has already sucessfully done the DI on the watercraft. The motor looks just like the E-Tec 600.
The Polaris DI was flawless without issues.

I thought the main obstacle with Orbital DI was the it's inability to run high rpm's in a snowmobile application . Do boat motors and watercraft run 8200 rpm ?

Yes, that was a limitation in the past. In watercraft applications, max RPM only reaches about 7200. Closely after that the system is incapable of working. There have been some improvements and updates now though which will allow it to run the RPM's required by a typical snowmobile engine.

I was on a mercury site todat looking at the optimax di they use, wondering why polaris doesn't make a deal with merc?

Is there any info on the DFI ATV Polaris is building fo the military???

Mercury has a deal with patent holder, I think it is Orbital.

Maybe Polaris will do something for 2010-2011. I would like to see this in the IQR called the XLT 1200 430 dry, new design plastics.

From what I've seen in the outboard world the Orbital system used by Mercury in their Optimax Outboards is far more reliable, stronger, and gets better fuel economy than the E-Tec system used by BRP in their outboards. Both systems require the use of specific oil which you only buy from the manufacturer so far. E-Tec's might be lighter, but they do not have the durability and longevity of the Mercury and Orbital system which is proven.

Polaris is in the right direction going Orbital. They had the upper hand when they partnered with OMC 10 years ago, but went away from it. OMC's were slower and didn't last as long as Yamaha's and Merc's back then, and still today.

I have to disagree there, orbital is much heavier, and more complex than e-tec or hpdi, and merc had lots of teething problems. Besides E-tec has no break in, merc ships every engine with a warning sticker stating that the warranty will be void if their break in procedure isn't followed, and the ecu will be checked to verify that.
For those that dont know, the entire point of DI is that the fuel is injected late in the cycle to keep any unburned from getting into the exhaust
E-tec has a stratified mode which allows super lean running at part throttle, it is like having an engine 1/3 the size for good economy

There are 5 E-Tec's where I live, two 75's, two 115's, and a 40hp. The 75's suck down the fuel more than Yammi F115's do that are on bigger boats and at cruising speeds, WOT you can forget about fuel economy. Merc's are coming out huge this year. All the E-tec's have had their issues and were in the shop already, except the 40 as it doesn't go far. I'll stick with a Yammi F115 for now, Mercury Optimax is my next outboard.

how does the resonance of the tuned pipe pull extra fuel into the pipe ?
it used to be the transerports.
does a dfi add more fuel at correct time to feed the pipe?

somthing that always stumped me in dfi technology

Although the rest of your post was good, I disagree with the part above. As a huge fan of snocross, I watch all of the races televised on SPEED. Two seasons ago, Robbie M. got a few holeshots, but over the course of the whole season, the other brands almost always left the Yamaha behind at the start of the race. The difference was even more pronounced this past year. Tucker Hibbert and Ross Martin's 2-stroke 600s dusted the Yamaha sleds on the holeshot time and time again during qualifying rounds ... and during the final rounds when a Yamaha was occasionally present.

For some strange reason, my 115-horsepower 2003 Pro-X 600 runs side-by-side with a friend's 2003 RX-1. Two years ago, I was beating him badly up to 95+ mph (speedo), but he's since done some mods (including a Power-Up kit). Are the Nytros and Apexes that much quicker?

I wouldn't be surprised if Doo comes out with a turbo in that buggy.