Long time reader / 1st time poster.
Was wondering about exhaust system and relative impact on performance. After market cat back systems claim 5-15 hp gain. "less restrictive airflow" is often times cited. Is this all marketing hype or is it legit?


The Infiniti / Nissan products give cause to wonder. The same basic 3.5 engine is mated to various exhaust systems (G35 sedan single exhaust dual tip, G35 coupe dual exhaust, 350 Z dual exhaust and Maxima dual exhaust with count them 4 tips), how much difference in these applications does less restrictive exhaust flow help in boosting the hp / engine performance?

 

On the TL, exhaust won't give you much hp, at the most 5hp, but more like 1-3 hp. Its a waste of cash if you wanted HP, its mostly for sound.