PR2 Racing ECU

[Popik]

I ran the RP Race muffler first on my 500, and then on it as a 550 and found it to produce about 2 hp better than the FMF as well. It especially carries the power out further than the FMF on my bike without loosing midrange torque. I have also tried the RP Race 47mm throttle body on both the 500 and 550. It It was too big and did not work at all on the 500...with the 550 it did produce 2 more hp on the top end...but lost 4 ft/lbs in the midrange. For both the 500, and now the 550 a PR2 bored to 44mm (43.7 actual) or a 44mm throttle body from a 450sx has been the best so far.

Does RP race make a head-pipe for the 450/500?

Did you find a source for a header on the 500 ? Im looking for something from RP race to work on a 2022 501 but nobody wants to commit to anything fitting lol

 

[CB-BLR]

Did you find a source for a header on the 500 ? Im looking for something from RP race to work on a 2022 501 but nobody wants to commit to anything fitting lol

I now run a RP Race full exhaust off of a 450 SX. I did have to cut off the center flange on the mid pipe as it did not align with anything. This exhaust pulls 1000 more rpm than the stock head pipe with the RP Race muffler. Lloyds performance helped me with this when they were doing my motor.

With their ported head and the RP race 450 sx full exhaust, the 47mm throttle body also worked the best...netting 74hp. The Lloyds said that I could probably get another couple hp with this combo using the RP race 50mm throttle body. They also have a new cam profile that I will be trying next year. Their personal 550 is producing over 80 hp!

Chris