how to get more 800 doo power

sledshedrevy

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i havent a xp sled in the shop with the mod on it so as i could take a pic of it . just ordered the alumi tube we will build them out of today .
inner id is 3 inch from intake sock to the top of the air box on the carbs .the sock is bigger than the cone it sits on and the pulseing of the throttle helps keep it clean when built this way .we do cut the top off the air box on the carbs and put our adaptor top on that will connect up with the snorkelend that comes thru the cab just on the left side top .doesnt hold snow and air flows over it . the sock tower that sticks up from the cab is made of lexan and will take the abuse of tree riding and roll overs if that is how ya get unstuck .
the rave valve mod came about when we had a sled that visually would not open the power valves all the way . no matter what we did it would not open . new components and the computer would not show any failure , even thou we could see that the valves wouldnt open and the sled just ran ill on top end as it wouldnt open up even on clicker 6 at the shop .
frustrated i decided to make the power valves open by exhaust chamber pressure . this accompolished easily . sled test now was normal rippin power that we wanted for mtn riding.i shave the valves down 200ths so they are lighter and aids in earlier flow as well . i drill a hole in the base of the power valve . right were the inner pressure port comes into the base and blows the diaphram open . i removed the spring under the plastic cap and thru it away and screwed the cap back on . still leaveing the two smaller springs were they were .
now block off the steel inlet tube and plug the hose end comeing from the rave valve solenoids .job done , now watch how well the thing lights . no jetting change required .
yes this works well on the big bore 800's, same approach applies on the bb to make power , if you dont mind spending money on higher octane fuel you will see the best results as you increase the compression ratio for the fuel .

here's a cool part about the snorkel kit . the front air box isnt being used and now makes a wicked storage spot once u take it out and gut it , put a door on it and you have dry warm storage .
 

sledshedrevy

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the etec works very very well and has a thumbs up from me .the other thing that we are playing with is the use of the polaris primary on the motor
the main short comeing of the tra is that it looses it's ability to squeeze the belt as the arms move out , typically why we never see the last inch of the primary getting used unless on flat terrain . i call it stalling .not only do the arms stall under load they are now just about starting to climb the ramp .
add the fact that the secondery spring is got a high end load and now the poor primary is struggling to get this to open as well and you can undestand the reason the belts run hot .doo's azz backwards approach with there reverse angle helix is all a band ade to try and walk the fine line and narrow range the primary can oporate in .
polaris primary has substantial more squeeze at the point the doo primary stalls .polaris primary doesnt have the ability to start as strong as the doo but that is why polaris secondery helix starts at 58 degrees and quickly goes to 42 degrees . spring end load pressure comparisions are poo 260lbs finish and doos 305 finish .
oh and just a side note the intake on the etec is 50mm as compared toothe other models at 40 mm .they gave it the air it needed and they gave the air intake a huge improvement , thats why they make the power they do and is why we go after the intake on the 08/09/10's
 

tex78

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hey al.... what about an 07 800r ? stock motor with vee's reeds....stock pipe , mbrp can...
i ride around 3000 feet at home and around u guys..... mabe a port and pollish ? head with a bit of a bump up in the comp?

don't want to run av or c gas.... just a bit more power...

i think i lost a ring locating pin late last year so its coming apart here in the next week or 2....

thanks jeff

hey al what about me?????????
 

sledshedrevy

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tex78 the 07 800r motor can use the rave mod , i charge 100.00 to do it . i mod the stock heads as well for 150.00 , the slp single for an 06 works on your build and if you use a team secondery use the 48/42 helix with red/pink spring , primary ramps i will tear petes off to check what i have in it for him .we have run a 07r since it came out and woould put pete's sled up against the etec easily. his also has a drop and roll which is the cherrry on top for the 07 chassi indeep snow .that we usually ask 1000.00 to do the drop and roll on , but this makes an 07 a real weapon.
 

tex78

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tex78 the 07 800r motor can use the rave mod , i charge 100.00 to do it . i mod the stock heads as well for 150.00 , the slp single for an 06 works on your build and if you use a team secondery use the 48/42 helix with red/pink spring , primary ramps i will tear petes off to check what i have in it for him .we have run a 07r since it came out and woould put pete's sled up against the etec easily. his also has a drop and roll which is the cherrry on top for the 07 chassi indeep snow .that we usually ask 1000.00 to do the drop and roll on , but this makes an 07 a real weapon.

i have enough problems with the stumps ect... for the drop and roll being even lower... i have put some thought into it tho before and thanks...
mine is also stock tra7 clutching primary and stock roller secondary.... was thinking i needed to clutch it ... and keep the motor stock size....

i put in the new etech gilotines and i never had a chance to stop and get ya to do the mod to them.... so whats the comp after ur done with the stock head? was thinking the aftermarket heads cool better ???
 

sledshedrevy

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depends on what a guy wants to burn for fuel , but normally 13.5 to one for 91/92 octane .
when we do the drop and roll the steering geometery improves and the clearence is improved , basically gives you 2010 xp geometery .we build a protective cover for the chain case.spetty sturdy ., it is very noticable as to how much better it gets around in the deep stuff .
 

deaner

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Ive heard of some guys adding a shim to the rave valves to achieve the same effect. What are your thoughts on this Al?
 

sledshedrevy

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you could shim them up, but the big gain is in the system blowing them open, instead of waiting on the system to do it .shaveing them makes them lighter and i suspect easier to open.i have a mill and a lathe so it was easier for me to just shave them .
we do have a air box we built for pete's so we could accomidate a snorkel.his is pretty gutted . no head lite as we run our own and that on the rev chassi allows the air we were after , on some of the rev chassis i have had i came in and out of the dash hole onthe right hand side and used a 90 degree bend and had the snorkel stick above and leaning forward of the dash .
 

tex78

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depends on what a guy wants to burn for fuel , but normally 13.5 to one for 91/92 octane .
when we do the drop and roll the steering geometery improves and the clearence is improved , basically gives you 2010 xp geometery .we build a protective cover for the chain case.spetty sturdy ., it is very noticable as to how much better it gets around in the deep stuff .

so a stock head with 13.5 or a aftermarket head with 13.5 ? thats the comp i want....
 

deaner

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I added a 14:1 engine tech head to mine last year and it was a night and day difference. I ride at 6000+ feet and run 50/50 av/premium. With just the head I had to add 3.1 grams per arm!! No BS.
 

sledshedrevy

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thats just what i mean , squeeze it and it just gets better . 13.5 ....91oct
14.0.....a little avg gas
15.0.....straight c12
16.0......straight c16
all depends on what you are willing to pay hahahaha
c16 head with twin cranl shop twins is about as good
as it gets in processing the max air
timing key needed ..4degree below 5000ths feet and 2 degrees above 5000ths feet
advance
when you are processing more air in the same given time frame / distance from top of exhaust port to top of stroke \
you need to light the fire sooner to allow the larger charge to get burnt ,before it passes the push zone of the pistons downward thrust.
higher elevation we loose some of the charges volume and therefore dont need as much advance .
doo automatically retards the timing when the sled sences it is above 5500ft..2 degrees
 

revbyu

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So just curious if you dont machine the rave valve does it still give you the same benefits - if you do machine the rave - what part of the rave do you mill off?
 

BIG HEAD

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the etec works very very well and has a thumbs up from me .the other thing that we are playing with is the use of the polaris primary on the motor
the main short comeing of the tra is that it looses it's ability to squeeze the belt as the arms move out , typically why we never see the last inch of the primary getting used unless on flat terrain . i call it stalling .not only do the arms stall under load they are now just about starting to climb the ramp .
add the fact that the secondery spring is got a high end load and now the poor primary is struggling to get this to open as well and you can undestand the reason the belts run hot .doo's azz backwards approach with there reverse angle helix is all a band ade to try and walk the fine line and narrow range the primary can oporate in .
polaris primary has substantial more squeeze at the point the doo primary stalls .polaris primary doesnt have the ability to start as strong as the doo but that is why polaris secondery helix starts at 58 degrees and quickly goes to 42 degrees . spring end load pressure comparisions are poo 260lbs finish and doos 305 finish .
oh and just a side note the intake on the etec is 50mm as compared toothe other models at 40 mm .they gave it the air it needed and they gave the air intake a huge improvement , thats why they make the power they do and is why we go after the intake on the 08/09/10's
Al, have you ever tried the Super Torquer Steam Roller arms on a TRA 7?
 

sledshedrevy

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havent tried them , stopped playing with the arms when a wise ole guy told me what was needed. do they have added weight behind and in the middle of the arm?
 

BIG HEAD

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Look at them and give me your opinion on the design, had them on for three yrs and they will shift out past that wall. The only flaw I have found is the bushings on the bottom don't have side bushing material like the doo arms..they have stainless washers. The ramps that come with them are mounted in a different place, therefore curing the TRA issues.
 

win

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Now that was a great read, im totaly interested in the snorkle, Al can you PM me if your around
 
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