Popular Hot Rodding has had a couple of very good ones from true pro's. The problem is they end up contradicting these same pro's with general comments in their everyday articles. If we are just talking exhaust, not headers, on a stock engine you can't go to big.
This is a pretty broad statement. Specific to the MN12? After the cats? Before the cats? How far from the exhaust manifold do I have to be for size to not matter?
On a modified engine, if you lose torque due to exhaust, the cam timing events are wrong. Too many times, especially on mods such as cams, to our MN12's that is exactly what goes wrong.
Explain, please. What difference does it make if I have a stock cam or an aftermarket cam?
There are no off the shelf setups for our size of car so anyone installing these packages is already involved in compromise. The loss of bottom end torque (really not torque but horsepower) is caused by moving the power curve to higher rpms while trying to move a heavy a s s car withit.
Why is the distinction between torque and hp important?
What seems to offset that is smaller pipes but that is simply restriciting the overall curve to gain through a narrow low rpm band while killing the the whole rest of the powerband. Seat of the pants improvement low, yes, actual no.
Above, you said the exhaust is moving the powerband upward in the RPM range. Here, you say it's choking the motor. Can you be more specific about what causes each affect? Bigger pipes, smaller pipes? What's the ideal pipe size for a stock motor?
It's a real simple rule, specific to efi, if you have to make inlet or outlet smaller to get your car to perform, the cam is wrong. No ifs. I know I will get arguments with I did this and got this or so and so said, this article said, etc. Just think of it this way, would you rather breath through an open mouth or a straw? Try it. At some point common sense needs to rule.
This is the part that interests me most. Why is it specific to an efi engine?