When you increase the duration or lift of a valve opening you lose idle quality and emissions quality in exchange for performance. the exhaust cam and intake cam are almost the same, while the exhaust cam has softer edges producing longer "duration" and therefore bumping performance a little. its not that aggressive, so i dont really need stiffer valve springs, but i do lose mpg with a slight gain in bottom end torque and throttle response. if i/you went with a web cam or ron woods race cam, stiffer springs would be needed. but honestly, for the sacrifice that ive seen in gas consumption vs power increase, i dont think it was really needed. im sure with a proper tune, exhaust, and filter, that would be MORE than enough for competitve riding, afterall, i dont think any of the BRP race teams even do cam work or head work.
now im no mechanic or expert, so if theres anything thats wrong please correct me im still learning as well!
