Why did Doo choose to make their turbo work opposite to how a turbo normally works?

acesup800

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It doesn't work opposite. Airplanes have been doing this since 1963. It is called a Turbo Normalizer. It is simply a different way of adjusting the wastegate. All the other components work exactly the same. How many times are you going to ask the question?
 

Longhairfreak

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I used to think the Freak was just a drunk. Now I starting to think he may be mixing chemicals with his home brew. Have fun with the ladyboys.


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Longhairfreak

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It doesn't work opposite. Airplanes have been doing this since 1963. It is called a Turbo Normalizer. It is simply a different way of adjusting the wastegate. All the other components work exactly the same. How many times are you going to ask the question?

So I'm thinking by weeks end someone will have a fix so this sled can run constant boost instead of gradual?
 

maxwell

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So I'm thinking by weeks end someone will have a fix so this sled can run constant boost instead of gradual?

im confused as to why anyone would care what a mountain sled does for boost at 0-6000ft? generally riding is between 6000-10000 and its making boost in those ranges
 

pfi572

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im confused as to why anyone would care what a mountain sled does for boost at 0-6000ft? generally riding is between 6000-10000 and its making boost in those ranges

For years sledders talked / wanted just enough boost to keep stock power at elevation !!
Wouldn’t it be awesome if the manufacturers would do this ?
Soooo ................. ???
Keeps everyone entertained I guess ?
Good on BRP as I think it’s awesome what they did .
 

banditpowdercoat

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Why? For reliability thats why. If a engine is built to produce 165HP at sealevel, BUT, do that reliable and all day, every day without issues and without over stressing the engine. Then, when you add boost per elevation, this, like was already stated is a HP Normalizer. It is letting the engine "SEE" Sealevel air pressure, at elevation. This maintains the HP level the engine was designed for and does not stress the engine in any way different than running at sealevel N/A does.

Y;all are stuck on the, I can make X HP numbers. Well any other turbo out there is Atmosphere referenced. That means, As you climb, the the turbo produces the same PSI that you set down low.
BUT, the atmosphere pressure drops. 14.7PSI at sealevel, 10.6PSI at 8000ft. SO ya lost 4PSI at 8000PSI, Boosted or not..... But This new setup compensates and ADDS boost at the same rate the earth looses it

Another way to see it, A 210HP @ Sealevel boosted sled is....... approx 165HP at 8000Ft!! Stock HP up high, but stressin the crap outa it when your cooking your Chef-Boyar-Dee in the parking lot.
 

Pistonbroke

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im confused as to why anyone would care what a mountain sled does for boost at 0-6000ft? generally riding is between 6000-10000 and its making boost in those ranges


building on this, does everyone know what the definitions of absolute pressure and gauge pressure are? Herein lies the holy grail of spooly bois and elevation...... oooohhhhmmmmmmmmm
 

greenthumb

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The mcx kit I had on my Yamaha 10 years ago was designed to compensate for altitude and deliver constant power. It had an electronically controlled boost tee. It's not a new concept for snowmobiles.
 

cdnredneck_t3

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I'm not a Doo loyalist by no means. But I think this is an awesome advance. Very close to if not the same throttle response as NA. No tinkering with clutching until over 8000ft. Factory warranty. Even if you don't ride a Doo it will push Cat and Poo to up their game. We all win.

For simplicity Linghairfreak, it is set up to maintain 14.7 psi absolute Manifold Air Pressure. A normal spring waste gate will open at a differential Pressure because you have boost pushing on one side of the diaphragm and atmosphere plus a spring on the other. If it has a 5 psi spring it will take 19.7 psi to open at Sea level or 15.7 at elevation.
 

Dazzler

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The mcx kit I had on my Yamaha 10 years ago was designed to compensate for altitude and deliver constant power. It had an electronically controlled boost tee. It's not a new concept for snowmobiles.

My 2011 Assault was set up similar. The boost was set at 6psi sea level, I would see as high as 9-10 psi where we typically ride.
 

Longhairfreak

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My 2011 Assault was set up similar. The boost was set at 6psi sea level, I would see as high as 9-10 psi where we typically ride.


So if I have 20 lbs at sea level I can expect to see 28 lbs where you ride?
 

canuck5

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im confused as to why anyone would care what a mountain sled does for boost at 0-6000ft? generally riding is between 6000-10000 and its making boost in those ranges

I have to agree with this a true mountain sledder what’s peak performance up top. I also think the biggest restriction is octane. These high performance two strokes already require 91 for the compression ratio. Even at 4 psi down low if I was a betting man someone ripping a heat soaked sled across a farm field in wot long enough could get it to detonate. We will know if it’s only ever offered on the summits.
 

skegpro

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I have to agree with this a true mountain sledder what’s peak performance up top. I also think the biggest restriction is octane. These high performance two strokes already require 91 for the compression ratio. Even at 4 psi down low if I was a betting man someone ripping a heat soaked sled across a farm field in wot long enough could get it to detonate. We will know if it’s only ever offered on the summits.
Don't even need a turbo to do that.lol.
 

Dazzler

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So if I have 20 lbs at sea level I can expect to see 28 lbs where you ride?[/QUOTE

Sorry LHF I can't answer that for other kits, I know with boondocker kits you can. I've had their set up on 4 different sleds (soon to be a fifth) and never an issue other than there was a noticeable turbo lag on the one kit with the inner cooler and bigger turbo. I run that kit at 15 psi, it was a blast in the open but not so much in the trees.
 
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