Just install non resonated test pipe in my g37 sedan , reason why i changed was my stock cat got clogged pretty bad.. with test pipe i like more throttler sounds but it seems quite..
my friend owns BMW 428i coupe that have muffler delete its way louder than mine..

Is there any way to make little louder and get deep tone ?

i was thinking magnaflow 11386 x pipe , or flow master series muffler

i dont want to drop like 1k on exhaust system...

thank you

 

Why not delete your mufflers like your friend?

you can easily un bolt both rear mufflers and temporarily drive without them on for a week to see how you like the sound.

 

or like your title suggests, get a hfc or straight pipe

 

Need to get rid of the stock mufflers...Mufflers muffle sound. Test pipes free up the cat restriction but be prepared for a raspy tone if you aren't running resonators.