Invidia N1 + Invidia catless front pipe question
 

Recently, i got installed the invidia N1 and pair it with my invidia catless front pipe. This combinations produces a nice rumble when letting off the gas, when downshift, and occasionally during accelerations.. i think it sounds great.

My questions, how is that rumble produced? Is it coming just from the catback or does the engine plays part on it?

Reason i ask is because to my understanding, the "subaru rumble" sound is produced by UEL headers, and the stock header in the BRZ is equal length.

What do you guys think?

Less cats/resonators to negate the sound I guess...

by the way, do u feel a difference in throttle response or power with a catless frontpipe? Is the torque dip minimized?

torque dip is still there... the gains are on the top ends rpms i believe..