Ok, I know that the hp rating for the 2007 sp800 is 54hp @ the motor. And the 2008 sp800 is increased to about 58hp @ the motor. Now the 700 motor in the ranger xp700 is rated @ 40 hp. Is the sp700 rated at 40hp too? If so, that is a huge jump from the 686cc motor for the sp700 to the 760cc motor for the sp800.

Also, the sp500 is rated @ 36hp @ the motor, but the ranger500 is rated @ 30hp @ the motor. Is polaris detunning the 500sp motor and the sp700 motor for their rangers or what???? Not sure whats going on there.

That means that there is an increase of about 31% hp from the sp700 to the sp800 over only 74cc's. Isn't that too much or what do you guys know about this?

 

The engine's rating in the ranger makes perfect sense. Most likely they retuned the engine to make more torque down low to get the larger vehicle moving. The ranger doesn't need a lot of hp since they want it to max out at around 40mph. Most of the rangers will be used purely for work, therefore the torque will be needed more.

Remember HP is totally based off of the torque and RPM of the engine. Higher RPM higher HP.

 

Good point subyman.

 

Cam Profile and timing setting
mostly play the role in these engine hp differences.

 

the ranger 500 is not the H.O. version of the motor.

 

timing and cam and valve size plays a big part of the increased hp in the 800 while keeping the same cc's.

 

the only difference between the 800's is the cam is bigger, they took the cam from the rzr and put it in the 800, and they put some different setups as far as the fuel injection goes, can't do anything about the timing on the twins, pushrod motor, therefore can't mess with the timing and the head is all the same.

 

well the valves have differnt part numbers so there differnt. i was told they were bigger, but dont know for sure. i was also told they advanced the timing a bit (like they do w/ the offset key ways) but there again this is what i ws told by a delaer so who knows.

 

Just looked it up, valves are the same number for o7 and 08.

 

i stand corrected. i just relooked up and i saw a differnt pn# thought the intake had changed becasue it had this.
VALVE-INTAKE, 35MM
5136197 (replaces 5132696
thanks for correcting me kerbbirds.