HPS can increase rpms?

[chrishew]

Hey guys
Just stumbled across a bit of debate over this in the 119hp prank thread. HAHA. Got me thinking. I bought a 12 Pro and it has the HPS can on it. I won't get out until Thurs so no idea how it runs yet but going by there website PAR claims an increase of 150 rpm. Now originally I thought to myself oh well I guess it must make a little extra hp then maybe 1hp. How I understand it is an increase in hp will result in a increase in max rpms and to keep using the full potential of the higher hp I add extra weight to my primary clutch to reduce my max rpm back into the engines peak hp range (which for these sleds I've heard is around 8-8200 rpm). If this increase in rpm is not due to a increase in hp then is it because of superior flow characteristics that create less turbelance in the can or a reduction in back pressure. I know a 2 stroke engine needs just the right amount of exhaust back pressure and this why you can actually see a decrease in hp from some cans or pipes that are not specifically or properly designed for that engine. Same rule applies to changing clutch weights for elevation, air is denser at lower elevations therefore more fuel + more air = higher cylinder compression and more hp. You need to run heavier weights in the primary at lower elevations to compensate for the increase in hp.

Also anyone who has only modded with the HPS can if you could testify to actually seeing a rpm increase that would be great.

Thanks guys just throwing this out there to try and learn a thing or two.

 

[ditch1000]

I installed an HPS can on my 2012 last year. I remember the rpms going up some and the sled has always ran great. I didn't change any weights because when I ride the mountains, my rpms are running 8100-8200. So thats good enough for me.

 

[sledhead80]

Last year I also just did the just HPS can on my sled and yes the rmp came up 150, that put me between 8200-8000 in the mountains. I also did not change any weights in the primary as my sled always ran at the rmp I wanted it to and I had no issuse what so ever.

 

[chrishew]

Thanks for the feedback guys. So I guess PAR's claims of 150 rpm increase seems true. Anybody got theroies of why this is because I would have ususally agreed with others that have said you should not see a performance increase from a can just weight savings but doesn't seem to be the case here.

 

[dirtbiker77]

the change of rmp isnt due to the hp, you actually loose hp. i dont care what anyone says a can with less back pressure will not give you hp it will take it away. its the pipe that can gain with the can due to the fact that they recreate the back pressure in the pipe and can. you can do just one. have to do both to gain any kind of hp. thats also why you need to use a fuel commander with the combo.
a can alone looses back pressure making the engine increase the rpm cause of the change in flow.

 

[hpjunkie]

Have a HPS can on my current ride (not a Pro). The HPS can is tighter (more restrictive) than stock. The manufactures (insert brand here) make one can for all application. It has to work at sea level where you need a "looser" can than say at 6000'. At times one can/silencer will be better than the other due to losing less hp than the next. Some might call this a gain. If you have access to a flow bench, you can make most cans flow the same as the best one, whether it be with a insert or simply a stratigic dent from a ball peen hammer! l.o.l As always. mfg (bean counters) only want one can/silencer. If people only ran their mtn sleds at 6000+ & not at sea level to 2000', you might see variances. In the end, cans loose weight, if you want a little more get a "easy button"!