I have a magnaflow muffler on my custom 3" exhaust and its quality is great. Sounds better than I hoped for when I installed it. I get compliments on how good my car sounds all the time. 3" is really big for a honda, I would guess thats the problem.

 

Just boost it. All your problems will be solved.

 

i believe its the lack of backpressure in ur system. the 3 inch piping on ur NA car is overkill, and the exhuast gases are very turbulent without a turbocharger to muffle the sound. it will sound much better/quieter with the turbo.

 

i know how to fix it...

buy my turbo