Do you have a C5 platform car? Did this help with any other car? I’m not an engineer, and I’m not an auto service tech, but all ideas / suggestions / feedback / questions welcome.
This is very helpful and informative for the members. It is old information but it still helps none the less.
To expand your thinking, think about this: If there is so much thought placed on the intake side of the engine to get air in then why isn’t that same thought placed on the exhaust side of the engine?
The exhaust actually does more to pull air and fuel into the engine than the intake does most of the time. The NA engines even use valve overlap where both the intake and exhaust valves are open at the same time to pull in more air. However the stock exhaust limits how much gasses can get out of the engine which causes a restriction to how much can get in through the intake. Just like in a line into a bar or club. If you can’t get people out then you run into the limit of how many people can get in. Then there are headers that (when properly designed) work to flow the gasses out between a certain rpm range. Much like a single stage intake manifold then exhaust headers will only be efficient in a certain RPM range. Wouldn’t it make much more sense to have multiple length runners for the both the intake and exhaust to really maximize the flow of the engine?