The Boss 302 is a boss in every sense of the word. It's the leader in the Mustang hierarchy and a dominant force in the performance world. We've already seen the benefits of the CNC-ported cylinder heads, altered calibration, and extended rpm range; and with boost, this thing is an animal!
But what kind of gains are available with simple bolt-ons?
To find out, we headed to AmericanMuscle.com's facility in Malvern, Pennsylvania, where the company's orange Boss was sitting on the dyno, anxiously awaiting our arrival. After making a few baseline pulls, we were ready to change some parts.
Prior to strapping the Boss to the Dynojet, the AM crew pulled a JLT Performance carbon fiber cold-air intake, Kook's Custom Headers' long-tube headers with an off-road X-style mid-pipe, and a Magnaflow axle-back exhaust system out of inventory. Follow along as we throw a cold-air and exhaust at a '12 Boss 302!
1 AM’s Boss was in stock...
1 AM’s Boss was in stock trim when we started. With only a few thousand miles on the clock, it was broken in just enough to throw some parts at it.
2 Mike Wilson of Bama Custom...
2 Mike Wilson of Bama Custom Tuning piloted the Boss during all dyno runs. The Boss laid down 380 rwhp and 329 lb-ft of torque for our baseline.
3 AM supplied a JLT Performance...
3 AM supplied a JLT Performance carbon fiber cold-air intake (PN 62023). We’ve seen this intake pick up as much as 30 rwhp in other applications, so we were excited to see how it would fare on the Boss.
4 After a few minutes, the...
4 After a few minutes, the stock intake and airbox was removed, and the JLT was resting in its place. While the intakes were being swapped, Wilson wrote a tune for the intake. After loading the tune with an SCT Xcal3 handheld tuner, we were ready to spin the rollers once again.
5 When the run was over,...
5 When the run was over, we were rewarded with 401 rwhp and 345 lb-ft of torque. That’s a peak gain of 21 rwhp and 16 lb-ft of torque.
6 The underside of the Boss...
6 The underside of the Boss was stock, but that was about to change.
7 The first order of business...
7 The first order of business was the Kook’s Custom Headers’ long-tube headers. The 13/4-inch headers should free up a bunch of exhaust flow and help make some extra power in the higher-rpm range.
8 The headers were followed...
8 The headers were followed by an off-road X-style mid-pipe, also from Kook’s Custom Headers.
9 The exhaust was finished...
9 The exhaust was finished up with a Magnaflo axle-back to give the Boss an aggressive exhaust note.
10 Photo courtesy of AmericanMuscle.com...
10 Photo courtesy of AmericanMuscle.com The new exhaust fits nicely and looks right at home under the Boss. Although the side pipes have been removed, the new exhaust should offer more than enough rumble for just about every enthusiast.
After Wilson revised the tune...
After Wilson revised the tune yet again, it was time to work the Dynojet one last time. This time we were rewarded with 440 rwhp and 278 lb-ft of torque. With a gain of 39 rwhp and 33 lb-ft of torque, our power production has come to just under the factory flywheel rating of 444 hp. Not bad for a day in the shop!