Ford Mustang Dyno Chart

We like these results better. The headers gained us 10.26 in horsepower and an even better 14.69 lb-ft of torque. But the underlying lesson to all of our dyno work on a basically stock Mustang is this: Don't expect big horsepower and torque gains unless you're willing to enlarge the rest of the exhaust sys-tem along with whatever goes onto the side of the cylinder head. In our estimation, adding a 2-1/2-inch exhaust system with some free-flowing mufflers would make either the K-manifolds or the headers do much better. We would expect the K-code castings to be worth 10-12 hp, while the headers in front of a bigger system should be worth 25-30 hp or more. We've also tested long-tube headers on popular stroker engines in the past, and have seen even higher gains on these healthy, deep-breathing engines.

Installing Performance Exhaust For A Ford Mustang - Exhausting The Possibilities

We like these results better. The headers gained us 10.26 in horsepower and an even better 14.69 lb-ft of torque. But the underlying lesson to all of our dyno work on a basically stock Mustang is this: Don't expect big horsepower and torque gains unless you're willing to enlarge the rest of the exhaust sys-tem along with whatever goes onto the side of the cylinder head. In our estimation, adding a 2-1/2-inch exhaust system with some free-flowing mufflers would make either the K-manifolds or the headers do much better. We would expect the K-code castings to be worth 10-12 hp, while the headers in front of a bigger system should be worth 25-30 hp or more. We've also tested long-tube headers on popular stroker engines in the past, and have seen even higher gains on these healthy, deep-breathing engines. View Related Article