<div class="FTQUOTE"><begin quote>Originally posted by: RED800

is the xp broke in, how many miles on the 850, i know 4 strokers take some time to break in?</end quote></div>

i read in one magazine that over the course of a 200 mile ride the 550 xp gained 6mph top speed thats HUGE....

 

I don't know... the XP has more HP at the rear wheels than a 500 EFI has at the crank... doesn't sound to bad to me. I know my 500 is no slouch, and the EFI should have even more oomph. That still makes the 850 seem pretty nasty to me.

Maybe those Terracross tires are costing it a HP or two. That would put it near or better than the 07 Can Am.

I read somewhere that some Can Am guys were complaining that the 09 didn't seem to have the grunt that the 07 (or 08 ???) had... in spite of the numbers Can Am claims.

 

i raced a clutched,piped o8 can am 800 the XT model and beat him 3 outta 4 times!!but only by a foot or so but i still won so that being said the 850 has more hp by far,mine had No engine mods at all

 

<div class="FTQUOTE"><begin quote>Originally posted by: DCT

I read somewhere that some Can Am guys were complaining that the 09 didn't seem to have the grunt that the 07 (or 08 ???) had... in spite of the numbers Can Am claims.</end quote></div>

Wasn't that was before they found out the 09 had a limiter screw installed so the throttle wouldn't open all the way..maybe I am mistaken but I think I remember hearing that...
No such luck on the 850....not that it is slow..but I'll take free HP any day on anything lol..I looked and best I can tell the throttle plates open fully....
I'm still tweaking the Airbox mod,air filter,exhaust and Optimizer combo..I think mine is fast enough now..at least for a little while...it will hit 40mph (speedo indicated,27" tires) from a dead stop in about 180-190'...that's easing into the throttle until she gets moving a little...no way you can nail it wide open from a stop and keep the front down on pavement...
I'm not sure how that compares to other machines...feels pretty quick though..
The brakes work well too..I think I could do 0-40-0 in about 220' on pavement,lol

 

<div class="FTQUOTE"><begin quote>Originally posted by: HIGHOCTANE

Wasn't that was before they found out the 09 had a limiter screw installed so the throttle wouldn't open all the way..maybe I am mistaken but I think I remember hearing that...

</end quote></div>

Could be... I didn't follow it that closely. LOL I ruled the Outty's off my list a while back for several other reasons not related to the power.

Doesn't really matter to me what the dyno numbers are... the 850 has more than enough power for me. [img]i/expressions/face-icon-small-happy.gif[/img] Plus IMHO, it has more than enough other "pluses" that put it in a class of it's own... at least for now. LOL

 

I highly doubt an ATV drivetrain soaks up 50% of the horsepower before it gets to the ground.

 

<div class="FTQUOTE"><begin quote>Originally posted by: HIGHOCTANE

<div class="FTQUOTE"><begin quote>Originally posted by: DCT





No such luck on the 850....not that it is slow..but I'll take free HP any day on anything lol..I looked and best I can tell the throttle plates open fully....

I'm still tweaking the Airbox mod,air filter,exhaust and Optimizer combo..</end quote></div>


The throttle plates do open all the way. However there is alot of room for improvement in the area of the throttle body.
The port match up between the head and intake is pretty poor, luckily there is enough material in the intake that matching the ports is possible.
The throttle body bore is 40mm but the port it mates to on the intake is 42mm and the port size of the plenum is 38mm. Ideally the throttle body should be bored to 42mm or at a minimum tapered out to 42mm and the plenum can be ported to match.

 

<div class="FTQUOTE"><begin quote>Originally posted by: WOLF1

<div class="FTQUOTE"><begin quote>Originally posted by: HIGHOCTANE



<div class="FTQUOTE"><begin quote>Originally posted by: DCT











No such luck on the 850....not that it is slow..but I'll take free HP any day on anything lol..I looked and best I can tell the throttle plates open fully....



I'm still tweaking the Airbox mod,air filter,exhaust and Optimizer combo..</end quote></div>





The throttle plates do open all the way. However there is alot of room for improvement in the area of the throttle body.

The port match up between the head and intake is pretty poor, luckily there is enough material in the intake that matching the ports is possible.

The throttle body bore is 40mm but the port it mates to on the intake is 42mm and the port size of the plenum is 38mm. Ideally the throttle body should be bored to 42mm or at a minimum tapered out to 42mm and the plenum can be ported to match.</end quote></div>

Is the TBs tapered down at the exits to 38mm to match the plenum or does the air hit a lip?

Sent you a PM..

 

The air hits a lip at each transition. The biggest is between the intake and cylinder head.

 

dremmel anyone ?