Wow, I should have logged in from home last night lol.
Would there be any downsides to going axle back?
Also would that be a cheaper option?
The downsides of going axle-back are generally:
a) Not as much power (Correct @Vancity808)
b) Slightly quieter exhaust note (subjective downside)
c) Less bragging rights and knowing you only have an axle-back

d) Sound may not be the same as a cat-back system
The upsides of going axle-back are generally:
a) Less expensive than a full cat-back system
b) Slightly quieter exhaust note (subjective upside)
c) Easier to install
From my understanding... When modding engine parts like exhaust if you don't have enough air flow in to the engine you basically not gaining but loosing HP. So if you are getting an exhaust you def need upgrade your intake to go with it to maximize..
The max HP can gain from each mod is 5-10 HPs.. Mark you have more accurate statistics?
This can be generically true with some cars but does not apply to the VQ37. We had made upwards of 18 rwhp on the 370Z with the stock intake on our cat-back exhaust. Now we have not seen those kinds of numbers on the Q50 for a few reasons we believe. Instead of reworking the motor to make more HP, Infiniti/Nissan just tweaked the intake and exhaust system (like what they did with the Nismo models) to get more power. So any power gains that we have gotten from the VQ's in the 370Z and G37 have lessened. I don't have any official dyno numbers, but I know they weren't as good as the gains on the G37.
So far, if it sounds as good or even better than the catback system, with a significantly cheaper price and no any sort of performance loss over stock then I am in!
We would not anticipate any power losses with an axle-back. However we would not expect to see much of any gains. It would be almost purely a style and sound piece.
any idea how much you guys would be selling them for stillen? because that plays a huge factor when it comes to choosing between the catback and the axle back.
I cannot comment on pricing at this time (would need to discuss with production and R&D). All I can say is it would be less expensive than the cat-back system if we went ahead with it. Do not expect it to be half the price of the cat-back or anything crazy like that though.