DOO XP Verse Nitro RTX

[shadow637]

It's as close to a weightless reverse system as you can get, and will only work on a 2 stroke. It is not physically possible to run a 4 stroke engine in reverse. 2 strokes can do it all day long...

I don't think that statement is completely correct- while running in reverse the oil pump is also spinning backwards. That means no oil injection, they will run for a while like that but not all day... Still an awesome system though.

I'm just sick of my Rev letting me down when there is snow on the ground, winter is too short to lose time fixing your sled. We have tons of new snow now in MN and my 600HO is sitting on my workbench waiting for parts. I don't care how light the Rev XP is, next year it's a Nytro for me... I like blue way better than yellow anyway...

 

[sledneck27]

Sledneck, what is F1's latest tech to run 20,000 rpm? I thought they had solenoids or something other than mechanicals to run the valve train.

Sorry, I dont know jack about F1 cars.

F1 is around the 20,000 RPM value. They use a pneumantic system for valve control. The running a four stroke in reverse thing was briefly discussed around here once before. I don't remeber the specifics, but a certain Yamaha peep made a comment that it didn't work very well. Lead me to think they tried it but couldn't get it to work well enough to take it to production.

From what I could find on the web, Valeo is extremely close to production versions of the camless engine. We'll see.

 

[silversurfer]

I'm just sick of my Rev letting me down when there is snow on the ground, winter is too short to lose time fixing your sled. We have tons of new snow now in MN and my 600HO is sitting on my workbench waiting for parts. I don't care how light the Rev XP is, next year it's a Nytro for me... I like blue way better than yellow anyway...

Exactly. Dunno why people get so caught up in that, a 510? lb 4-stroke is still very light and an amazing accomplishment.

 

[revster]

I'm just sick of my Rev letting me down when there is snow on the ground, winter is too short to lose time fixing your sled. We have tons of new snow now in MN and my 600HO is sitting on my workbench waiting for parts. I don't care how light the Rev XP is, next year it's a Nytro for me... I like blue way better than yellow anyway...

Exactly. Dunno why people get so caught up in that, a 510? lb 4-stroke is still very light and an amazing accomplishment.

....and that is why Yamaha will steal Rev owners.

But not everybody has had problems, I have 8000 miles on 2 Revs and only $22.00 total worth of repairs not including maintinance.

 

[AKrider]

In my mind the best new generation Rev would be the XP chassis with the old, circa 1999 500ss motor. I'd like a light weight sled with reverse that has good power. Still I love my 4-stroke Vector even though it is heavy.

I actually read on Maximumsled.com that the new Phazer weighed less than a 500SS in wet weight. That is crazy if it is true!

 

[doo rider]

In my mind the best new generation Rev would be the XP chassis with the old, circa 1999 500ss motor. I'd like a light weight sled with reverse that has good power. Still I love my 4-stroke Vector even though it is heavy.

I actually read on Maximumsled.com that the new Phazer weighed less than a 500SS in wet weight. That is crazy if it is true!

well it will be out in production this year.....bringing back the old TNT name for it...and it will be 399lbs DRY. Which if it does actually come in at that will be 100lbs less than the Nytro. Mind you 10-15HP short.

 

[sledneck27]

The 500SS's 600cc engine only makes about 104 HP, thats all it ever made, thats why Doo markets it in the 500cc class. The new Nytro makes 130+HP, making the HP differential between the two quite a bit more than 10-15. As far as the weight, sub 400lbs dry with a liquid 600 seems more like wishfull thinking to me, unless of course they stick it in a revamped RF Chassis, and even that model with the 550F motor weighs in dry at 410lbs. We'll see, but I'm not biting on these XP chassis weight claims, and I'm certainly not buying into a sub 400lb liquid 600 in the XP chassis, the numbers just dont add up. Doo is claiming 435lbs dry with the 800R in the XP chassis, theres no way theres a 35lb+ differential between the 800 and any 600, no way.

 

[craze1cars]

Recent history has the Doo 800's and 600's at nearly identical weights. Same size engine blocks I suppose...

 

[silversurfer]

I'm just sick of my Rev letting me down when there is snow on the ground, winter is too short to lose time fixing your sled. We have tons of new snow now in MN and my 600HO is sitting on my workbench waiting for parts. I don't care how light the Rev XP is, next year it's a Nytro for me... I like blue way better than yellow anyway...

Exactly. Dunno why people get so caught up in that, a 510? lb 4-stroke is still very light and an amazing accomplishment.

....and that is why Yamaha will steal Rev owners.

But not everybody has had problems, I have 8000 miles on 2 Revs and only $22.00 total worth of repairs not including maintinance.

Nope, certainly wasn't implying they all had problems, I know many Doo riders have had many trouble-free miles. But overall, Doo's reliability is not as good as Blue, and that's why they are my primary choice. If it was, my next sled might be an XP - apparently the Nytro RTX is 520 dry. A 20 lb reduction with that mill is nice, and it still would be my #1 choice were I to buy one tomorrow. But I am praying they will find a a way to shave another 20-30 lbs or so in the next couple of years before I get back in the sport on a regular basis.

 

[ReX]

I don't think that statement is completely correct- while running in reverse the oil pump is also spinning backwards. That means no oil injection, they will run for a while like that but not all day... Still an awesome system though.

Does the oil pump really not work when the engine is running in reverse? Seems like a pretty big flaw if that is true.

It's not hard at all to design a pump the pumps in the same direction no matter which way the crank is turning. Take a look at any piston type air compressor for example.

 

[RTXs]

I think the riding position on the new nytro is going to be like the OLD rev, with your knees bent more than 90 degrees, not comfortable for long rides. Anyone else see this??

 

[RedRX1]

To really be fair on these weight comparisons, they should all be wet with the amount of fuel and oil needed to run a standard realistic distance on typical trail conditions. This would be a good test for Sled Tech. Weigh them dry and all full, run them all over the same 100 mi conditions, speed, ect. Weigh them at the end of the run. This way you can figure out the weight of liquids necessary for this standard distance and add that to the dry weight. This would be a truly marketing free valid comparison.

 

[RedRX1]

If they all did this, we would all have decent sized gas tanks!!! You don't have to fill them if the weight bothers you, but it would be nice to have reserve on the long hauls.

 

[revster]

I'm just sick of my Rev letting me down when there is snow on the ground, winter is too short to lose time fixing your sled. We have tons of new snow now in MN and my 600HO is sitting on my workbench waiting for parts. I don't care how light the Rev XP is, next year it's a Nytro for me... I like blue way better than yellow anyway...

Exactly. Dunno why people get so caught up in that, a 510? lb 4-stroke is still very light and an amazing accomplishment.

....and that is why Yamaha will steal Rev owners.

But not everybody has had problems, I have 8000 miles on 2 Revs and only $22.00 total worth of repairs not including maintinance.

Nope, certainly wasn't implying they all had problems, I know many Doo riders have had many trouble-free miles. But overall, Doo's reliability is not as good as Blue, and that's why they are my primary choice. If it was, my next sled might be an XP - apparently the Nytro RTX is 520 dry. A 20 lb reduction with that mill is nice, and it still would be my #1 choice were I to buy one tomorrow. But I am praying they will find a a way to shave another 20-30 lbs or so in the next couple of years before I get back in the sport on a regular basis.

Yup I agree with you 100%. Although I haven't had any trouble with my Revs, I know I won't be able to keep them as long as I would a Yamaha. If I didn't have an 07 in the garage I'd be ordering a Nytro for sure. Maybe my wife will let me get a 2010..

 

[doo rider]

The 500SS's 600cc engine only makes about 104 HP, thats all it ever made, thats why Doo markets it in the 500cc class. The new Nytro makes 130+HP, making the HP differential between the two quite a bit more than 10-15. As far as the weight, sub 400lbs dry with a liquid 600 seems more like wishfull thinking to me, unless of course they stick it in a revamped RF Chassis, and even that model with the 550F motor weighs in dry at 410lbs. We'll see, but I'm not biting on these XP chassis weight claims, and I'm certainly not buying into a sub 400lb liquid 600 in the XP chassis, the numbers just dont add up. Doo is claiming 435lbs dry with the 800R in the XP chassis, theres no way theres a 35lb+ differential between the 800 and any 600, no way.

you are correct....103 HP show in rotax info I have.....so 27+ HP difference...I was looking at the HO specs by accident. As for the 399lbs sled...its happening ....everyone will find out tomorrow.....the reports for the 435lb sled are for the non X model....the X comes in even lower. and the TNT has all lightweight body parts, all alum. shocks, etc. and the 500SS is around 10-12lbs lighter I think it is, than the 600SDI. The X model 120" MXZ 600SDI is spec'd at 418lbs. Its a toss up as far as I am concerned....DOO has the weight advantage and HP to go with it for the 800 class, but Yami has the engine reliabilility, I wish I could combine the 2.