ok. this is kind of stupid, but i'll go ahead and take a hit for this anyways. after hitting over 3.4k mi. for some reason, my engine sounds louder and agressive. being this is my first brand new car (wish i had my ekhatch, back).

JDMi

 

Errr...sounds like you hit post too early or something.

Anyway, several people on ephatch.com have stated that their
car "seems" faster/louder/better the longer they've had it. Most
people say this seems to happen around 10K miles or so.
Also, people seem to think that the ECU in this car isn't very
aggressive - i.e. it takes it a while to find optimal settings. It could
be that your ECU is just now "peaking" or something of that sort. I wish
there were some more ECU hackers/tuners for these cars to give us
a solid yes/no on this type of thing, but it certainly is plausible.

So, you may not be that off and deserve that bad of a flaming.

 

I think this was common of all cars with k-engines in them. The car gets a little faster after some time when new. It's most likely just the engine breaking in.

 

My engine has 30,000 miles on it and let me tell you my EP is the fastest it's been since i bought it.

Take heed though, be nice to your 3rd gear, the syncros go quick with it.

Only word of advice i have,

2nd to 3rd, if your not racing, let the rpms drop a little and don't speed shift it unless your racing or whatever you deem worth of a fast shift.

3rd gear syncros are the first to go.

 

The exhaust usually gets a little louder on cars over time. Stainless exhausts more than others.

 

My Si is barely on 2k miles and the engine feels a lot better and it sounds louder than when it was new, felt kind'a weird driving a quiet civic