The only sound as common as a loud racecar in the paddock at any NASA event is the clattering of a diesel engine. Diesel trucks make great tow vehicles and NASA members own a lot of them.
I had the chance to get out of my 2005 GMC 1500 crew cab with a gasoline engine and into a 2005 Chevrolet 2500 crew cab diesel with less than 50,000 miles for a price that worked for me. The new-to-me truck also was bone-stock, cleaner than mine, and had more options, so the decision to buy it was easy.
Naturally, as a car guy, I can’t leave well enough alone, so I began looking at forum websites dedicated to GM diesels to find out where the trouble spots were and eliminate problems before they surfaced. My goals for any modifications to the truck are to increase longevity and improve fuel economy. I don’t need it to go faster. I have a racecar for that.
I figured exhaust would be a good place to start, so I ordered a Banks Engineering Monster exhaust system from a speed shop here in town — buy local, I always say. Banks makes a couple of different stainless-steel applications for this truck, including dual- and single-tailpipe systems with polished stainless and black chrome exhaust tips, or no tip at all. I chose the single-tailpipe system with the polished stainless tip, which cost about $500 out the door.
Banks says the system triples exhaust flow and cuts backpressure by up to 98 percent. The Banks system is 4 inches in diameter compared with the 3-inch factory exhaust, so I thought for sure it would improve fuel economy. After several trips to the racetrack with a trailer in tow — before and after the exhaust install — I can’t say I noticed an improvement in fuel economy.
Banks doesn’t advertise that the Monster system improves fuel economy, but it does say that the system lowers exhaust gas temperatures. Without an EGT gauge, I couldn’t measure exhaust temperatures, but I did notice that the coolant temperature was about 30 degrees lower when towing a trailer up the Grapevine pass in Southern California, a 4,000-foot climb and descent over the Tehachapi Mountains.
To install the system, I took the truck and the kit to Troy Martin at Full Scale Hot Rods in Ventura, Calif. In addition to building some beautiful cars, Martin owns the same kind of truck with a similar exhaust system.
The system installs in an hour or so. Don’t do it in your driveway, though. Go to a shop with a lift. Trying to pull the old system off while your truck is on jack stands or ramps wouldn’t work. You have to kind of twist and snake it out between the axle, spare tire and body and there wouldn’t be enough room with the truck on the ground or even on jack stands.
If your truck has an extended cab, it might be necessary to cut a given length off the pipe that bolts to the catalytic converter. That lets Banks offer one kit to fit a few different trucks. Because my truck is a crew cab, we didn’t need to make any cuts.
In terms of quality, the system was first rate, and everything fit well. The exhaust note changed only a little bit. It sounded a little deeper than the stock system, but it’s no louder, which is good. After racing all weekend, the last thing I want to listen to is a loud truck on the way home. All in all, I’d recommend the Banks system. Here’s how it all went together.