i am planning on getting the HRC kit for my 450R and an aftermarket pipe and i wondering if the HRC kit gave the R more bottom end too, or is it just top end power? ive already asked this before but nobody answered. also what pipe has good bottom end? im looking at the "pro circuit, yoshimura, and curtis sparks. ive already done the 13 tooth sprocket but its still too tall in first gear. i would really apreciate your advice, thanks

 

I replied yesterday, but for some reason it didn't post. In the last issue, one of the magazines (ATV Action ?) did a comparison of the before and after HRC kit installation. There is a dyno, so I would suggest you find it and take a good look at it. As I recall, there was a pretty good boost on the low end, and a lot on the high end (which you should welcome, because you gave up some high end with your 13T sprocket).

The magazines should be running some pipe shootouts pretty soon. You might want to wait and see those before picking a pipe. I'm an FMF guy myself.

 

OK, I was at work, so I picked up the magazine. (After I read them, I take them to work for the guys there to read). It is the August issue of ATV Action. (Why they almost never include the torque curve, is a mystery to me???)

Unfortunately, there isn't any major difference in horsepower until you get to ~5,500rpm. By the time you reach 8,500, there is an increase of over 10 hp. (from a max of 33.1 to 43.8), compared to stock. You already are running a 13T sprocket, so that should get you more quickly up into the higher rpm's, where you have more hp. And, you are going to top out quicker on the high end, so some added hp up there, should be welcome too.

I just put on Holeshot XCT (22" rear/23" front) tires. These are the hot setup for desert racing, but of course, you pay the price on the low end, because it raises the effective gearing. I will be ordering a 13T sprocket TOMORROW! Plus, I have an FMF Factory-4SL muffler and PowerBomb Header that I have not yet installed, so hopefully that will help.