If you own a diesel pickup, chances are good you bought it for a reason, whether to haul your tools to the job site or to tow your boat to the lake. Today's diesels, including the Ford Power Stroke, GMC Duramax, and Dodge Cummins, offer more standard horsepower and torque than their gasoline-fed counterparts. Of course, more power still isn't enough for some diesel truck owners who want, well, even more.
Fortunately, there are like-minded manufacturers, such as Corsa Performance Exhaust, who feel the same way. Corsa has been making 100-percent stainless steel exhaust systems at its Berea, Ohio, headquarters since 1989. Can an exhaust system really increase horsepower and torque? According to Corsa, there is a straight answer, a straight-through answer, that is. Your engine is a giant air pump, so the more efficiently it moves air, the more power it makes. Corsa claims its systems increase exhaust flow by as much as 47 percent over the stock setup, due to the company's less-restrictive, straight-through design. The company says this significantly reduces backpressure and lowers exhaust gas temperature, which allows the turbocharger to build boost quicker and enhance the truck's hauling and towing power.
Inside the truck, Corsa has gone to great lengths to keep things quiet with its Reflective Sound-Cancellation (RSC) technology. To fully explain RSC technology, we would need to review space-age noise-suppression techniques. However, going into all of those equations would be a bit boring. All you need to know is that sound waves are reflected within the muffler, producing a cancellation effect, which lowers or completely eliminates that in-cabin drone. That means you can still talk to your passengers and enjoy music while cruising down the highway.
Besides the Ford Power Stroke series, Corsa also makes 50-state emissions legal diesel exhausts for the GMC Duramax, and a Dodge Cummins system is in the works. Expect to pay around $1,000 for one of these 4-inch-diameter 304-grade stainless steel systems. To put these claims to the test, we traveled to Full Throttle Kustomz in Bedford, Ohio. The shop had recently purchased a new F-350 Super Duty, featuring Ford's 6.0L Power Stroke turbodiesel engine and graciously agreed to aid our investigation.
What's In The Box?
The 304-grade stainless steel Corsa kit for the '07 F-350 consists of 4-inch-diameter mandrel-bent tubes, a straight-through muffler, a hydroformed tip, and all of the necessary brackets and such for the installation.
Power Pipes: The Install
Full Throttle Kustomz' F-350 turbodiesel dyno-tested at 197 hp and 362 lb-ft of torque at 2,800 rpm at the rear wheels with the stock exhaust system. On a truck this tall, you won't need a lift-heck, you might not even need a jack. This one was put up on a lift to help us get good photos for you. Removal of the stock system began with loosening the clamp, using a 15mm socket on the intermediate pipe located directly in front of the muffler.
Next, the pipe was cut with...
Next, the pipe was cut with a saw, right in front of the last hanger. This let us get the pipes out later without removing shocks and stuff. A soap and water solution was mixed in a bottle and sprayed on all the hangers and rubber isolators. The soapy solution let the hangers slide out of the isolators a lot easier. But, if you don't believe us, try it dry. All of the hangers were popped free with a prybar and then the factory system was snaked out. Note: Be careful, because the factory stuff is pretty heavy.
Here is a side-by-side of...
Here is a side-by-side of the two systems. The design of the Corsa system (left) is noticeably more streamlined than the stock system (right), allowing for less restriction. The 304 stainless steel doesn't look too bad, either.
Installing the Corsa exhaust...
Installing the Corsa exhaust began with positioning the intermediate pipe over the outlet pipe. The hanger was then inserted into the rubber isolator, and the clamp was snugged up but not tightened all the way.
The muffler was then slid...
The muffler was then slid over the intermediate pipe outlet, and the clamp was snugged up but again not tightened all the way. It is important to make sure the small drain hole in the rear of the muffler is orientated to face down when the muffler is installed.
The tailpipe was routed over...
The tailpipe was routed over the axlehousing and hooked up to the mufflers outlet. The hydroformed exhaust tip was then slid over the tailpipe (inset).