Hey all,
My current car and mods-
2011 g37s

Injen intakes
High flow cats
Up rev tune

I just removed an Invidia catback because of the volume. Loved the Hp, but not the noise. I see that there are some axel back systems out there. My question- are axel backs as loud as cat backs, and do they provide any hp gain? Any help is greatly appreciated!

 

In reality since its axel back the HP gains are probably minimal at best....I have the Tanabe axel back and it has a nice deep rumble. But you can talk to your passenger and hear the radio just fine when your not led footing it...
I dont think in reality a cat back system adds much HP either....unless you have a tune to take advantage of it...

 

Thanks. With my uprev tune, there was no doubt that there was hp increase. Especially in the mid rpm's and up. Not only butt dyno, but watching the tach move MUCH quicker to redline than it did without the catback.

 

Regarding axle back, they are not generally as loud as cat back but some can still be lound (depends on your standard of loud). If its too loud you can mate it with a motordyne resonated Y-Pipe it will take the edge off the sound. Gives it a lower warmer tone.
I have the Sport muffler and it was slightly edgy when I installed it. Then I got the resonated y-pipe and now its low and deep. You can still hear it but its not intrusive and at cruise you can barely hear it at all with the radio off.

 

Great info. Thanks!

 

When I put my axle back on I noticed no difference at all in power, just more of the sexy VQ motor sound


That being said, when I installed a Top Speed y-pipe I did feel a bit more pull up top, probably opened up 2-3 ponies somewhere in the mid-upper range.

 

I just got my tanabe axle back out on yesterday. It makes the stock noise a tiny bit louder particularly at the 4K RPM level. It's JUST shy of perfect IMO. I hope HFCs give a bit more Noise but am very happy with it so far.