My friend just got one, It's basically a fast rice car. But the thing that shocked me was that his idle fluctuated from 1 rpm (barely any noise) to 2 rpm (pretty damn loud). He told me that he got bigger camshafts and that the noise was normal. He said he was told this by a mechanic. I really doubt that this is normal even though I was told it was.

 

does it fluctuate from 1k to 2k then to 1k then to 2k and so on and so forth? if so then he might have some loose vacuum lines.

 

If he has agressive cams that is absolutely normal. For example if you stick Crower Stage 3 cams in a lude it will rumble like a V8. Nice power but idle sucks. Needs some effort while in traffic.