Originally Posted by Bad70supreme
This is completely false! No gains if your car is bone stock, and in the case of the 1le probably no gain. But add some mods and the exhaust will come into play! The stock exhaust is NOT perfect, it has some ruff bends but on a stock car it works. Once you mod the idea that the stock exhaust will make the same power as aftermarket or custom setup is no longer true!
On a pure bolt on car (intake, TB, lt headers, tune) it has been shown and proved that replacing the stock catback with an aftermarket catback on the Camaro gives no gains.