1975 Chevy Laguna - The "X" Factor

In Stock Car racing, every last fraction of a horsepower matters-and that's why you see an X-pipe from Dr. Gas on every single Cup car in NASCAR. Although the exact science of why they work isn't fully understood, we do know this much: When any given exhaust pulse arrives at the "X" juncture, the pulse expands along both available paths. In doing so, a negative pressure wave travels back to the exhaust port, which aides in exhaust scavenging. Balance pipes, sometimes called "H" pipes, function similarly, however, the effect is diminished due to the balance pipe's smaller diameter and the added bends the gas flow is subject to.

After thinking long and hard about the exhaust options for our '75 Chevy Laguna (Project Talladega), we decided that a no-holds-barred NASCAR-style exhaust was what we wanted. We liked the idea of maximizing our power just like the big-name racers, and the look would be a perfect fit for our NASCAR-themed project. Moreover, with a solid-roller 408ci small-block lurking underhood, we figured the sound alone would strike fear in the sport compact crowd, and it has so far turned out to be a great deterrent with no takers yet.

When we called Dr. Gas to sell them on the idea, we were pleasantly surprised to find out they had been following Project Talladega since the start. They were waiting for our call, and had a recommendation for our Laguna already picked out. Just to be clear, there is no "bolt-on" side-exit exhaust kit from Dr. Gas. You buy components that you will have to fabricate into a unique system. When you receive your shipment of Dr. Gas components, you will have the option of building the system yourself, or bringing it to a shop. In either case, the cosmetic result you get will depend on the work you put into building it.

Straight from Dr. Gas's "NASCAR" parts bin, we received a universal 3-inch X-pipe made from oval tubing (part No. U3O, $399.95). The Dr. Gas folks matched this to a pair of 3-inch Street Rod Boom Tube mufflers (part No. BTM3, $550.90). Looking more like flat, side-exit exhaust tips than mufflers, the Boom Tubes are essentially open, with spin traps welded inside them to mitigate some of the sound. They are loud, so be forewarned that you may run afoul of the local gendarmes if they don't fancy your automotive style. As fate would have it, we drove our finished Dr. Gas exhaust on the Riverside, California, freeway during a Harley rally, and suddenly found ourselves cruising in the midst of 15,000 wild hogs. We got a big thumbs-up from all for two reasons: our satin black paint fit right in with the biker vibe, and because we were still the loudest thing on the highway. The scene could easily have been an outtake from a Mad Max movie.

Building an exhaust system like this requires special fabrication skills, and for that we turned to LP Racing of Upland, California. The "LP" in LP Racing is Lang Paciulli, who specializes in race car fabrication and TIG welding in particular. Lots of shops do welding, but it's MIG for the most part. For those shops, welding is an unpleasant necessity, but Lang's interest in TIG welding borders on compulsive. If two metal objects need joining, chances are Lang will TIG weld them-with a smile on his face. As a result, it's no surprise that he's good at it. Lang's TIG skills are known throughout southern California, and like many others, we sought him out for our Dr. Gas project.

For a TIG job like ours, Lang charges about $350, which doesn't include the parts or the labor to construct our custom double-hump transmission crossmember. Lang and Dr. Gas both say that TIG welding isn't a necessity for this operation, but it's Lang's specialty, and at that price, we decided to go with the flow. It took about six hours to build our Laguna's exhaust system with the parts provided by Dr. Gas. When the labor charges are added to the cost of the Dr. Gas components, our one-of-a-kind side-exit system cost around $1,330. If you need to extract the maximum power potential from your engine, and you like the visual and audio shock value of a side-exit race system, that price isn't out of line. (If it were a piece of high-end sculpture, you'd pay five times the price for it.) Next month, we'll be installing a brand-new, bolt-in steering box from CPP that has transformed Project Talladega's handling, so stay tuned.