So I bought a 2008 RAZR 800s that was tricked out by Dragonfire racing with High compression pistons and a custom ground cam, Dynojet rev box, Looney Tune exhaust. It ran great at elevation 4000 feet and above, had no issues but it didn't seem to have the power that the mods should have brought to the table. Took it to Oregon dunes in July and it ran like a raped ape! I thought this is good until it overheated on a 62 degree day. Turns out it was detonating and it blew head gasket, pistons.
Lesson 1: if you have high compression pistons U need Octane Boost or race gas at sea level.
Lesson 2: Dynoject Power Commander 3 does a very poor job of adjusting air/fuel ratio for elevation changes. (I thought that was why these are fuel injected.

Oh well, I took this as an opportunity to go BIG and installed the Muzzy's 850 Big Bore. After the first ride i must say WOW. I won't be beating any 900's but the mid range torque is incredible. The install was clean and I must say Muzzy's stuff is super quality look and feel. So, the thing I like most about the changes is in the open desert riding we do I don't have to have it floored all the time. It is much easier to drive as the power band is much more linear with tons of low end grunt. Top speed only went up 1 or 2 mph due to rev limiter but in trail riding the motor just doesn't need to rev as high. Seemed to benefit mileage a little as well. Overall, the kit is an expensive upgrade but much cheaper than buying an 900xp and all the upgrades. I am happy with the outcome and would recommend the Muzzy kit to anyone who can't afford $18k for a 900.

Oh BTW I did have it Dynoed before/after the install and and HP went from 38rwhp to 52.7 !

 

hi
did you put on dyno to see the hp you have
i have rzr800 2011 and i want to put this kit on
i have yoshimura rs8 full exhaust and epi clutch kit airrad kit
thanks for the info

 

perfect, I was looking for info on this kit to have one installed on my rzr thank you.

what fuel management does the muzzy kit use?