Is there anybody here that can customize the carnival's exhaust manifold and exhaust system for better flow? the warrnaty of my carnival is about to expire this november and I'm planning to further improve its performance. As is the performance of the carnival is superior. However, I fell that the stock die cast 4-to-1 header restricts the flow of the exhaust gasses.

The challenge is to create a tuned header that smoothly guides the exhaust gasses until it reaches the turbo. A heat shield is a must to protect the electronics near the firewall.

What will be its effect at the mid and low band rpm range? Will it be harder to drive in bumper to bumper situations? To my knowledge the modification will greatly improve the high rpm range of the engine.

let me hear your thoughts on this.