Got my new 5.0 mag today and opened it up to see a bolt on drag test of a 03 Mineral Grey Cobra. They baselined it and it made 360 rwhp and 358 lb-ft of torque!! Not too shabby. With a 2.5-inch Bassani cat-back, it made 371 rwhp and 362 lb-ft. With a catted X-Pipe, the Cobra made 378 rwhp and 374 lb-ft of torque. When they removed the airbox and put a K&N on, the power jumped to 400.0 rwhp and 383.1 lb-ft of torque

Wth just exhaust and an air filter, the Cobra was at 400 hp at the wheels.
On the drag strip, a set of M/T ET Drags were bolted on, and the Cobra ran a best of 11.95@116.27 mph.
Yep, a Mustang that produces 400 rwhp and 11 sec 1/4 mile passes with just exhaust and an air filter!!! Plus it has a factory warranty!!! Start saving your $$$$