Freestyle Xscream & DASA What's coming next..

[Hihi962]

I can't imagine going to a 3 cyl or huge jugs is the answer. I have seen this over the years in mountain snowmobile setups for years.
in a sled right now the biggest cc while still having it last longer then a week is 800. Yes they've tried 1000's, triples, and other big bore options but they start to leave the bore x stroke optimum area, were too heavy, and I am sure there were other issues causing so many failures.
thats like going back in time to the 70's and throwing in a hemi, just cause its big displacement.
i think the real direction would be a well balanced engine, and get the hp from fuel/oil injection. I would rather have an 1100 running a 3D rave valve with injection, then a big 1400 twin or triple..
To get a monoblock to fit 1400cc, that is gonna be one fat bottom end,just think about it, might as well make it a 60deg V engine.

my fuel injected snowmobile 800cc pushes 170hp stock, on 87pump gas.
my 885cc dasa is not even there, with TL on it.
I also think the sport would benefit from fuel injection, as this would eliminate flooding, enable quick starts after dismounts, and so on.. IMO, that's what I'd be working on, so that's what I think they'd be working on.

 

[Matt_E]

I can't imagine going to a 3 cyl or huge jugs is the answer. I have seen this over the years in mountain snowmobile setups for years.
in a sled right now the biggest cc while still having it last longer then a week is 800. Yes they've tried 1000's, triples, and other big bore options but they start to leave the bore x stroke optimum area, were too heavy, and I am sure there were other issues causing so many failures.
thats like going back in time to the 70's and throwing in a hemi, just cause its big displacement.
i think the real direction would be a well balanced engine, and get the hp from fuel/oil injection. I would rather have an 1100 running a 3D rave valve with injection, then a big 1400 twin or triple..
To get a monoblock to fit 1400cc, that is gonna be one fat bottom end,just think about it, might as well make it a 60deg V engine.

my fuel injected snowmobile 800cc pushes 170hp stock, on 87pump gas.
my 885cc dasa is not even there, with TL on it.
I also think the sport would benefit from fuel injection, as this would eliminate flooding, enable quick starts after dismounts, and so on.. IMO, that's what I'd be working on, so that's what I think they'd be working on.

The comparison with snowmobile engines is often attempted, but IMHO isn't all that applicable. A PWC engine does not employ a transmission and must deliver its usable power from 1000-6000 rpm (roughly). maybe 30% of that power actually makes it to the water.
Injection setups are vulnerable to the terrible conditions PWC engines get subjected to. Additionally, there isn't much of a market for any of this.

 

[Balduccimoto]

Exactly what matt_e said. Think of how linear the powerband is from idle to WOT. Thats anywhere from 0 mph to 50 mph it pulls without issue. It's ported and designed this way. Now compare to a yz125 that makes similiar hp numbers to a 701 - that little 125 has got a 701 smoked displacement vs hp numbers. That's because the yz125 is ported/designed to run at high rpm and can keep in the powerband by reaching for the next gear.

EDIT: What we really need (what I need) is a 1200 with a nice linear powerband and fuel efficient. I'd like to not carry 10 gallons gas to the surf through that long ride. Hybrid please?

 

[Hihi962]

I'm not saying use a snowmobile engine or dirt bike engine, but to follow the technology now being used in those sectors.

as far as the terrible conditions pwc are in, I am not sure what you mean? Have you guys ever seen what guys are doing to atv's these days, I have buddies that snorkel them and drive them around like submarines every weekend. Hot off the trail, straight into a cold stream, their fuel injection systems seem to take it.

but a hybrid, I could handle!

 

[Matt_E]

Who is going to pay to develop that for a dying market that is small enough as it is?
I doubt ATV engines regularly get submerged into fresh and saltwater to the point of corroding wiring to dust and destroying batteries.

 

[wsuwrhr]

The comparison with snowmobile engines is often attempted, but IMHO isn't all that applicable. A PWC engine does not employ a transmission and must deliver its usable power from 1000-6000 rpm (roughly). maybe 30% of that power actually makes it to the water.
Injection setups are vulnerable to the terrible conditions PWC engines get subjected to. Additionally, there isn't much of a market for any of this.

My thoughts exactly

 

[yamanube]

I'm not saying use a snowmobile engine or dirt bike engine, but to follow the technology now being used in those sectors.

as far as the terrible conditions pwc are in, I am not sure what you mean? Have you guys ever seen what guys are doing to atv's these days, I have buddies that snorkel them and drive them around like submarines every weekend. Hot off the trail, straight into a cold stream, their fuel injection systems seem to take it.

but a hybrid, I could handle!

You are posing two completely different sides to the argument, how much power does that quad make while under water? How much power does your snowmobile engine make while in a humid, nearly completely sealed fiberglass box on a sunny 95* day between 1000 and 8000rpms? The main "technology" in the dirtbike and snowmobile sectors that allows them to make that kind of power IS THE TRANSMISSION. You could port and tune a jetski motor to make similar power to a snowmobile motor on a dyno and blow everybody away with pointless numbers, then not sell enough to cover the development because it is not optimal for the application.

 

[sleddingfarmer]

I'm surprised these jet ski engines make anywhere near the horsepower they do...they get like virtually no fresh air! Its actually quite impressive.

 

[Hihi962]

...The main "technology" in the dirtbike and snowmobile sectors that allows them to make that kind of power IS THE TRANSMISSION. You could port and tune a jetski motor to make similar power to a snowmobile motor on a dyno and blow everybody away with pointless numbers, then not sell enough to cover the development because it is not optimal for the application.

why are you guys talking about transmissions? Of course it's a different application. But an engine is an engine, do you really think 2 stroke engines are that different? The only thing you can actually change is exhaust and ports to modify torque curves, rpm changes, and what not.
My old 1993 ski doo's still ran expansion chambers, still had power valves, , had oval ports, had hemispherical heads, and still used mikuni carbs.
these quad and snowmobile engines are flywheel dynoed, so that means NO Trans. If you actually look at it, a pump is a transmission, just engages water instead of belts and clutches.

if someone produced a fuel injection system, do you really think it'd cost way more then dual novi's, and a TL system?
look at it this way... Years back I bought a Yamaha scooter, it was fuel injected and the whole scooter brand new was only around 4K, it had 11 more hp then my buddies carb version, same motor.
I am not saying that is what they are doing, but is my guess. If carburation was so hot, why did every manufacturer and serious drag racer leave it back in the 90's?
I just think this sport is lagging in engine management because the following is so small. Otherwise, yes, some of us would be riding hybrid and fuel cell skis! Haha

 

[Matt_E]

And how many of those scooters do you think Yamaha sold to dilute the development cost?

 

[yamanube]

why are you guys talking about transmissions? Of course it's a different application. But an engine is an engine, do you really think 2 stroke engines are that different? The only thing you can actually change is exhaust and ports to modify torque curves, rpm changes, and what not.
My old 1993 ski doo's still ran expansion chambers, still had power valves, , had oval ports, had hemispherical heads, and still used mikuni carbs.
these quad and snowmobile engines are flywheel dynoed, so that means NO Trans. If you actually look at it, a pump is a transmission, just engages water instead of belts and clutches.

if someone produced a fuel injection system, do you really think it'd cost way more then dual novi's, and a TL system?
look at it this way... Years back I bought a Yamaha scooter, it was fuel injected and the whole scooter brand new was only around 4K, it had 11 more hp then my buddies carb version, same motor.
I am not saying that is what they are doing, but is my guess. If carburation was so hot, why did every manufacturer and serious drag racer leave it back in the 90's?
I just think this sport is lagging in engine management because the following is so small. Otherwise, yes, some of us would be riding hybrid and fuel cell skis! Haha

I think you are missing the point, the transmission isn't what MAKES the power, it is what makes the power USEABLE.
If you look at high HP snowmobile dyno graphs I would bet you find that they really start to climb around 4-6k and peak around 10k, you could tune a PWC motor similarly and probably get great numbers but nobody would want to ride it. The trans allows you to engage the drive later and keep it in that optimum power range, a ski is hooked up from idle on and a flat powerband up to 4k would make for a less than exciting ride. The prop pitch that 175hp at 10,000 rpms would need to hook up would be a dog at 3,000rpms. This is all speculation on my part of course.

 

[sniper]

I think you are missing the point, the transmission isn't what MAKES the power, it is what makes the power USEABLE.
If you look at high HP snowmobile dyno graphs I would bet you find that they really start to climb around 4-6k and peak around 10k, you could tune a PWC motor similarly and probably get great numbers but nobody would want to ride it. The trans allows you to engage the drive later and keep it in that optimum power range, a ski is hooked up from idle on and a flat powerband up to 4k would make for a less than exciting ride. The prop pitch that 175hp at 10,000 rpms would need to hook up would be a dog at 3,000rpms. This is all speculation on my part of course.

You are so right, a couple of years ago me and a buddy of mine sent a sxr engine to an enginebuilder that was very good at building snowmobile engines. He build our engine like it was a snowmobile engine and it didn't work at all. He had a dyno and the engine produced 127 hp. But it had all that hp on the higher rpm. If we jumped with the ski so the impeller got some air then it was fast like a mofo. But you could not make a turn then it didn't have any power.

 

[kx454]

XS and WDK use stroker cranks. XS machines the cases to accept 62T electronics. My question is when do we run out of carburetor?

These monsters are never held wide open for any extended periods.....I don't think that will be an issue...

 

[SuperN8]

Get ride of the direct drive and throw a CVT or Torque converter (torque multiplier) on there and keep the motors in the optimum powerband.
Or couple that with a wankle and run that biotch at 15,000rpm all day long lol

 

[kx454]

Exactly what matt_e said. Think of how linear the powerband is from idle to WOT. Thats anywhere from 0 mph to 50 mph it pulls without issue. It's ported and designed this way. Now compare to a yz125 that makes similiar hp numbers to a 701 - that little 125 has got a 701 smoked displacement vs hp numbers. That's because the yz125 is ported/designed to run at high rpm and can keep in the powerband by reaching for the next gear.

EDIT: What we really need (what I need) is a 1200 with a nice linear powerband and fuel efficient. I'd like to not carry 10 gallons gas to the surf through that long ride. Hybrid please?

125's make about 30 horse....

 

[Matt_E]

Get ride of the direct drive and throw a CVT or Torque converter (torque multiplier) on there and keep the motors in the optimum powerband.
Or couple that with a wankle and run that biotch at 15,000rpm all day long lol

CVT's are horrible at handling high (and variable) torque numbers without being huge. Besides, that arrangement would drop even more power. There are some four-stroke skis that use a reduction gear. The Yamaha FX series comes to mind, which use a modified MR1 engine that likes to spin at 10,000 rpm.
A Wankle spinning at 15,000 RPM would be useless without a similar (HEAVY) reduction gear setup.

 

[SuperN8]

CVT's are horrible at handling high (and variable) torque numbers without being huge. Besides, that arrangement would drop even more power. There are some four-stroke skis that use a reduction gear. The Yamaha FX series comes to mind, which use a modified MR1 engine that likes to spin at 10,000 rpm.
A Wankle spinning at 15,000 RPM would be useless without a similar (HEAVY) reduction gear setup.

Snowmobiles have been employing CVTs for like ever with similar sized displacement with great success. It would drop hp but may make for more torque down low while also maintaining a solid top end. Like having a 1st gear and overdrive.
I am no expert with CVTs but I have one on a mini bike and that thing might weight 3lbs total, lol, of course that only needs to handle 5hp not 150.
maybe having a demand for a small light weight transmission could inspire ingenuity and forever change the face of powersports.

 

[Matt_E]

I suspect you are right on the technical side - but I don't for one minute believe there is enough money or future in 2-stroke standups for any company to warrant spending that money up front.

 

[SuperN8]

I suspect you are right on the technical side - but I don't for one minute believe there is enough money or future in 2-stroke standups for any company to warrant spending that money up front.

You are absolutely correct on that, no company is gonna spend the dough on R&D!
Only way this would work is if someone can find something similar used for another project and they feel the need to add a Trans to their ski and they makeshift it to fit. Thank god for backyard engineering.

 

[sleddingfarmer]

The ski-doo 800 etec dyno'd at around 160, from the factory, and makes peak horsepower at about 8300 RPM. I believe the exhaust valves begin to open at something like 6500 RPM.

Just some fun facts for you. I owned a 2011 800 etec. Ran great, all the time, started super easily all the time. Would something like that work in a ski...? probably. Will anyone ever do it...probably not.

Carbs work just fine. I would rather have carbs on my ski than a retardedly expensive computer that is going to give me electrical gremlins all the time. My etec would throw random codes, and sometimes tell me to 'check battery'...I didn't have a battery. But it did always run good. But no thanks. I like it simple. Like the crank windows in my truck.