XC pipes

[fast shee]

What seems to be the best xc pipe for a 90 in stock form. I do plan on getting some porting done on the stock cylinder but would like to see what i can get out of it with a stock cylinder setup. Are any of these pipes more quiet than a stock unit. The series we run has noise level requirements. If at all possible i would like to get as much bottom end power as possible. My son drove it up the road and back for the first time and wanted to jump on his modded kfx80 instead because the power comes on smoother and revs much less. Any info please! Dont want to sell it but he does not like it the way it is now.

[chunky0071]

Putting a pipe on it will only make it rev higher and come on the pipe harder. With a little ride time he will learn the power and how to use it. Get him out in the woods in the rough and he will like the drr better every time he is on it. Porting and a pipe is going to make the bike hit much harder !