Jim Smart
January 1, 1998

Step By Step

View Photo Gallery
This is Flowmaster's American Thunder after-cat dual exhaust system for '86 to '93 5.0 Mustangs, featuring two-chamber mufflers, exhaust, and tailpipes.
These are the surgical instruments of the trade--a power saw with a fine-tooth blade designed for metal, 3/8-, 1/2- and 9/16-inch sockets and ratchet, a common screwdriver, and penetrating lubricant for stubborn hardware.
Because the factory installed the stock dual exhaust system prior to dropping the body over the rear axle, the tailpipes must be cut as shown, and carefully removed.
Getting the factory exhaust hanger out of the ozone-hardened rubber isn't easy. Pry the hanger as shown and the tailpipe will drop out. Just walk the pipe over the rear axle and out it comes.
Spray the exhaust pipe to catalytic converter bolts with penetrant and go have a cold one with your current copy of 5.0 Mustang. Then, remove the bolts as shown. Unless you live in a winter salt climate, removal is easy.
Slide the coupling rearward and remove the exhaust pipe from the cat.
Unbolt the muffler hanger and drop the muffler.
The OEM '86 Mustang GT mufflers baffled us because one was larger than the other. They are very restrictive.
Next, prepare the new Flowmasters for installation. The hanger attachment holes must be tapped to accept the bolts.
Position the mufflers in place and attach the hangers as shown. Clearance for these larger mufflers is a challenge.
Attach the exhaust pipes to the cats and run down the bolts.
Next, slip the Flowmaster tailpipe up over the rear axle and attach it to the muffler.
Install and tighten the clamps, making sure mufflers and pipes clear the body by at least 1/2-inch.
The tailpipe hanger slips into the original rubber hanger like this. The Flowmaster tailpipe is not stainless steel like the original equipment, so some chrome tips may be in order.

Well, well, well... our little ol' Minimum Wage Mustang is coming along quite nicely. Although it still looks like a junkyard dog, we've turned it into a nice-driving, good-handling, safe Mustang that's now ready for some modifications aimed at more power! If you're new to 5.0, let's back up and clue you in on this project.

A friend of the 5.0 staff, who has more ambition and know-how than money, bought this ragged, but reasonably sound, '86 GT for less than $2,000 with the goal of turning it into what every Mustang owner wants: an 11-second show car that can be used as a daily driver. Of course, we all know how dreams can warp reality, especially when the checking account is limited by a minimum wage paycheck, as is the case with our pal. So, we've attempted to build a car the way most of you would--a month at a time, as finances allow.

Our mods need to be chosen carefully. Unlike other magazine project cars where all the glorious parts come piling in the door as fast as the UPS guy can unload them, Minimum Wage Mustang is gonna take some time. We started off with a $150 monthly budget to spend on the car, but the minimum wage has increased a bit and the owner has decided to sacrifice some things (who needs a girlfriend, anyway?) to push the budget up to just over $275 per month.

For this installment, we decided to address both performance and image with a free-flowing--and louder--Flowmaster exhaust system. We went with a Flowmaster after-cat American Thunder exhaust system (PN 17113 for an '86 to '93 LX; PN 17116 for an '86 to '93 GT) because, at a street price of $230, it's affordable. This system's two-chamber mufflers bark like junkyard dogs on puppy uppers. As you will see, installing the Flowmaster system can be done in your home garage. Expect to wrestle with it a little bit, but it does bolt on without too much hassle.