Any idea why my car would sound different at a certain RPM range?

[ShiftinGT]

Hey everyone was wondering if anyone could chime in as to why my car makes a different noise between 3000-4000. After 4000 it goers back to normal as heard in the video below. [video=youtube;v8UbwBwJaxc]https://www.youtube.com/watch?v=v8UbwBwJaxc&list=UUNGVOrzfJRSwBVNZXeXAbww[/video]

 

[ShiftinGT]

Anyone?

 

[Kline12]

I'm confused as to what it is we are listening for. I hear your exhaust, and then a slight rattle? Is the rattle what you are referring to?

Edit: I re-listened to it. Are you referring to the engine noise? Or the exhaust noise? Not sure what exhaust you have, but between 3000 and 4000 RPM's my lm1's go from a deep rumble to an ear piercing scream. So depending on your set-up, that's just how your exhaust is. If you are referring to the engine noise, are there any shakes at 4000 RPM's? Does the front of the car rattle and shake? It could be anything from a batter motor mount, to something bad internally like a head banging around.

Give us a little more information on what's going on, and maybe we can help a little better.

 

[ShiftinGT]

Yeah sorry the audio quality isn't very good on the video. The exhaust noise is what i'm referring to. The car sounds like a honda civic or something between those RPM's. The exhaust is flowmaster 40's.

 

[VirtualSVT]

what kind of a cold air do you have?