Early dyno reports (850R)

[justinator]

Personally I think Dave may inhaled too many fumes from the dyno room lol. 2 stroke guys have been working with this engine for a while now and just about any tune over 205 is 93 octane and over 220 is race fuel but miraculously they now have 270 on pump playing on the dyno. Does it use a full tank of ice everytime you mash the throttle?

 

[earthling]

It will be a rocket for as long as it lasts. Dave is likely focused on the guy who hangs out in the shallow end of the lake, looking for suckers. It will play well to the blip-blip crowd. I personally cannot imagine the angst of knowing 'this could be it' every time you mash the fun button, it could be that one time it doesn't hold together, maybe its just me. F-that. Dave is doing what he can to make the motor safe which is avoidance of excess heat generation/detonation but there is always a weak spot, something will give. No thanks, I would stick with 'anytime I damn well want, repeatedly, for as long as I want' hp/reliability.

 

[Doc Harley]

Obviously Dave has the meth all jacked up to provide those numbers. And yes she'll burn thou it very quickly. Probably has an oversized tank in the works.
The following statement includes the Polaris Boost.
these high output sleds are solely used for events & sitting on the lake. Most of the guys "who know what they're doing" have the deepest of pockets and multiple sleds. I think "Brent68"or GMC68?!?! Can't remember & others.
Grenading a motor for them is no different then us changing a blown belt.
I've seen a few dragy times for Boosts wicked up to 250hp. They (typically) run nearly the exact same numbers that I have on 300hp. (6.35 660ft)
With two exceptions...
1) they were on hard pack, were I was on snow
2) they are on race fuel, I am on straight 93.

Lastly, if you think these 2 strokes can survive a day on the lake going back & forth drag racing...they might, but every pass is taking its toll on its life span.

 

[Upstater57]

I cannot imagine holding this to the handle bar across the lake for a mile at sub zero temps with high barometric pressure. When you pull the pin, Mr. Grenade is no longer your friend.

 

[Upstater57]

I cannot imagine holding this to the handle bar across the lake for a mile at sub zero temps with high barometric pressure. When you pull the pin, Mr. Grenade is no longer your friend.

With that said, it will be quick in a short run when clutched and studded properly.

 

[Doc Harley]

Here's an image of the 270hp run. Seems as thou they made this dyno report with water temps at 78°. Not exactly sure if that has a substantial effect on numbers?!?!

 

[DARKMAN]

Yeah, some people have more money than brains...

 

[Doc Harley]

Yeah, some people have more money than brains...

Well...haha. the guy i mentioned is more of a pioneer. I believe his Mach Z made 400hp last time I checked.
But I get your point.

 

[NYTurbo]

A 250 plus hp 2 stroke will embarrass a lot of 998s in a 660 drag .

Longevity as others have indicated may be an issue, and meth consumption is going to be substantial at increased hp levels.

 

[sideshowBob]

Here's an image of the 270hp run. Seems as thou they made this dyno report with water temps at 78°. Not exactly sure if that has a substantial effect on numbers?!?!
View attachment 179092

If the data is accurate, it indicates AFR less then 10:1....entering no man's land
I have no doubt at all that these Hurricane tuned 850s will be rockets but they will be a different beast then our tuned 998s are as the 998s can trail ride all day on pump gas and have the ability to unleash 300hp lake blasts with little reliability worries.

 

[earthling]

If the data is accurate, it indicates AFR less then 10:1....entering no man's land
I have no doubt at all that these Hurricane tuned 850s will be rockets but they will be a different beast then our tuned 998s are as the 998s can trail ride all day on pump gas and have the ability to unleash 300hp lake blasts with little reliability worries.

I wouldn't read too much into that. The sensors get fouled quickly when measuring a 2-stroke. The data shows it is running lean at mid-range and rich at WOT, which matches with Dave's comment that he is running overly rich at WOT for safety. Basically rollin' coal at those numbers, wouldn't want to be behind it.

Dave's complete comment:

"We have finished our largest pump gas tune for the skidoo 850 turbo on the dyno. I’m happy with making 270hp without knocking on 91 octane . This is up from the 260hp on a hot summer day. The afr is still rich but it’s running excellent and safe so I’ll leave the extra wot fuel in it for safety to insure that the winter afr stays where I want it. It will make more hp as the winter air sets in."

 

[Doc Harley]

Agree...the 850's set on kill w/chisels = a bad day for the 998t
But I can list results like this one all day long.
Results are in both dragy group & Polaris Boost group.

 

[NYTurbo]

those numbers are not impressive .

 

[Doc Harley]

those numbers are not impressive .

Agree...its my point to establish that not all 250hp Boosts are the same. Some are set up for trail riding, others are set on kill (for et) both have the same tune.
Same applies to Comp 850's and 998T's

That particular Boost claimed 250hp tune later in the post.

 

[74Nitro]

I wouldn't read too much into that. The sensors get fouled quickly when measuring a 2-stroke. The data shows it is running lean at mid-range and rich at WOT, which matches with Dave's comment that he is running overly rich at WOT for safety. Basically rollin' coal at those numbers, wouldn't want to be behind it.

Dave's complete comment:

"We have finished our largest pump gas tune for the skidoo 850 turbo on the dyno. I’m happy with making 270hp without knocking on 91 octane . This is up from the 260hp on a hot summer day. The afr is still rich but it’s running excellent and safe so I’ll leave the extra wot fuel in it for safety to insure that the winter afr stays where I want it. It will make more hp as the winter air sets in."

I dunno, IMHO it probably is 10-1 to keep it alive.