2007 GMC Yukon

With new technology and new trucks come new problems to work around when trying to add more power. For example, take the new '07 Tahoes from GMC; some of these SUVs come with active fuel management to cut down on how much fuel these hefty trucks drink. The AFM system deactivates four of the eight cylinders while cruising, effectively cutting the fuel load in half. While this is great for saving money on gas, it does bad things to the exhaust note. What was a nice V-8 growl turns into something that sounds more like a clapped-out fishing boat. We are not going to sit here and tell you a four-cylinder can't sound good because they can, but this truck is only a four-cylinder during cruising. So, you get this muffled burble, instead of anything that sounds high-performance, which GM hides by keeping the exhaust very quiet.

So, what happens when you add a high-performance exhaust system to squeeze out more ponies? Well, if you buy substandard parts, you end up just amplifying that nasty burble. Luckily for all of you power-hungry truckers, JBA Exhaust Company builds a full exhaust system that not only adds 14.5 hp, but it also keeps that burble under control. Mark Matthews from JBA says, "This AFM feature was something we tuned our products for to avoid an unpleasant exhaust drone when in four-cylinder mode. Once installed, the new headers and exhaust system were tested extensively on the dyno and in real-world road conditions to ensure the operation of the AFM was not affected."

The Cat4ward headers and stainless steel exhaust system are available for '99-'07 Chevy and GMC 4.8-, 5.3-, and 6.0L V-8-equipped trucks and SUVs. The headers feature all of the good things you want to hear from a set of pipes, thick CNC laser-cut flanges, mandrel bends, and stainless steel. To top that off, you also get a limited lifetime warranty. The muffler and tailpipe assembly share some of the same features, such as mandrel bends and stainless construction, but also come with a straight-through-designed muffler and a 3-1/2-inch chrome-plated stainless tip with rolled lip. You might be asking why JBA chromed a stainless tip: Stainless has a tendency to turn yellow, and the chrome prevents that from happening.

To complement this system, JBA also offers a set of the company's PowerCables, which feature less resistance than the factory wires for more spark energy, and 8mm jackets for higher temperature resistance. Because these wires are made by the same company that makes the headers, they have all the proper ends to fit the new pipes. The parts are designed to be installed at home with minimal tools needed, so don't be afraid to tackle the job yourself. But, if you are not confident in your abilities, a professional shop shouldn't charge you too much to put them in.

What's In The Box?

Headers: These headers have a one-piece design with 3/8-inch CNC laser-cut flanges and mandrel-bent stainless steel primaries to provide burn-through protection without sacrificing the easy installation. The patented JBA Firecone collector improves scavenging for maximum performance gains. The ceramic-coating is optional in silver polished or titanium finish for added thermal protection.		Gaskets: JBA supplies the best gaskets available with each header kit. For the late-model Chevy Vortec engines, they are multilayered and made of a special Dead Soft aluminum, which conforms to header flanges for the strongest seal possible. Dead Soft aluminum seals far better than copper gaskets. Because JBA's gaskets are constructed from solid metal, they will not blow or burn-out.
Wire Kit: JBA PowerCables are engineered with ultra-low-resistance wire-wound mag conductors, 8mm silicone jackets, and heat-resistant boots, so they can withstand severe-duty conditions as high as 700 degrees F. These wires have less than half the resistance of the factory wires, freeing spark energy, and increase performance without electronic interference. Each wire kit comes pre-labeled with the appropriate cylinder identified on each cable for easy installation.	Muffler & Tip: If you take a look inside of JBA's high-flow stainless muffler, you can see the straight-through design that allows it to flow more spent gases, while still keeping the sound tame.	The only part of the exhaust that most people will see is the end of the tailpipe, and JBA knows that, so it caps off the exhaust system with a 3-1/2-inch polished stainless tip that has been chromed to keep it from turning yellow.