Car Care
Going with the Flow, Part 2
Upgrading a Jeep Wrangler with a cat-back exhaust
Created by Steve TempleAs shown in Part 1, the stock headers on the Jeep Wrangler can stand for some improvement in both flow and durability. To maximize the performance gains of aftermarket headers, a cat-back exhaust system should be installed as well. You should see as much as a 25-hp increase using both components together. It doesn't make sense to increase the flow at one end of the tubing and leave the other constricted. To work effectively, the entire exhaust system needs to flow better.
For the section of the system located downstream from the muffler, the Stinger from Gale Banks features a super-sized, 2.5-inch tailpipe with a polished stainless tip. (The latter item doesn't give you any more grunt for getting up a steep grade, but it sure helps you look better while doing it.) The real performance benefit comes from the Banks Dynaflow, a straight-through performance muffler that markedly reduces backpressure after the catalytic converter for more power and efficiency. According to Banks, in comparison tests the Dynaflow flowed 501.2 cfm at 1 psi—a 141-percent improvement over the stock exhaust's 208.6 cfm.
Tools/Tips
Installation of both the TorqueTube and Stinger should take about a half-day in all, and requires a 1/4- and 3/8-inch drive ratchets with standard and metric sockets. You'll also need open-end wrenches, screwdrivers, pliers, and a torque wrench for the bolts on the headers. To make the job easier, recommended tools include a compressed air source, penetrating oil, a 9/16-inch swivel socket, floor jack, jackstands, a fuel-line quick-disconnect tool, and an acetylene torch.
A generous amount of elbow grease may be needed as well. Bolting on an aftermarket exhaust is basically a simple plumbing job, with the only real challenge being the removal of the stock system, which may require a welder's torch to loosen the clamp and joint between the muffler and catalytic converter. When lining up the hangers, the lower end should extend slightly forward to allow the pipe to expand with heat toward the rear of the vehicle. Overall, even if you encounter a few hurdles along the way, just go with the flow, and you'll improve your flow.
Resource
Gale Banks Engineering, 546 Duggan Avenue, Azusa, CA 91702, 800-438-7693, www.bankspower.com
Step 1
Pry the hangers loose on the stock exhaust system from the rear to the front of the muffler. Use some lubricant to loosen the hangers.
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Step 2
Use some firm persuasion to pry the stock system loose. It will probably take some effort to free the pipe.
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Step 3
If necessary, heat up the joint with an acetylene torch so it expands and loosens.
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Step 5
Note the differences between the stock exhaust and the Banks muffler and tailpipe. The Banks unit is said to flow as much as 141 percent better than stock.
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Step 7
Next install the Banks exhaust into the muffler. A bit of tapping may be needed to fit things snugly.
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