1971 Monte Carlo Exhaust - The Gas We Pass

This is not just an exhaust story. OK, so it is, but we're a little excited about this one. Why? We would like to introduce to you a vehicle that we have done little to no tech stories on, a Monte Carlo. A 1971 Monte Carlo to be exact. We plan to follow a frame-off rebuild of this vehicle from Harrison's Restorations in Upland, California. First, we needed to get this stock Monte Carlo to the track, run it through the ringer and see what kind of numbers we can squeeze out of it before we tear into it. Before that happens, we needed to fabricate and install an exhaust system; presently the remnants of a dual exhaust were all that was left on this Monte.

Harrison Ortis, a connoisseur of fine GM vehicles, chose to use Dynomax Super Turbo mufflers on his Monte, along with some Dynomax mandrel bent tubing. The mandrel bent tubing is actually made to fit late-model '90s Impalas, but when used on the Monte Carlo or even a Chevelle of the same year, it has near perfect clearance over the rear axle and around the gas tank.

As for the rest of the exhaust system, it was fabricated by Harrison and made to fit snugly and neatly under the Monte Carlo. Originally, this particular car came from the factory with just a single exhaust pipe exiting out the rear of the vehicle. Sometime during its life, the vehicle had a dual exhaust system added. The quality of the prior exhaust system is very much in question (we'll show you pictures later). As this Monte Carlo sits, it is running the stock 350 small-block and stock exhaust manifolds and a good, solid performing, system is all it needs to get her to the track and back. However, when the frame off takes place the exhaust will be replaced with 3-inch diameter pipe, headers and have an X-pipe system added.

A shot of the Dynomax Super...        read full caption A shot of the Dynomax Super Turbo mufflers (part number 17732) and the late-model, full size Impala tubing (part number 54017). This tubing fits nicely under the Monte Carlo.	Here are a couple of photos...        read full caption Here are a couple of photos of what's left of the old exhaust system. Look at those horrible welds. They look like stalactites hanging from the roof of a cave;...	...we're certain that Ray...        read full caption ...we're certain that Ray Charles could have done a better job on the welds.
Before getting started, Harrison...        read full caption Before getting started, Harrison started to mock up the system, which enabled him to figure out just where he wanted the mufflers to be positioned and how he wanted them to hang.	Since the vehicle is equipped...        read full caption Since the vehicle is equipped with stock manifolds, a couple of pieces of head pipe were cut, bent and tacked into place.	From the head pipe to the...        read full caption From the head pipe to the mufflers, another measurement was made, including the 15 degree bends. Since this system will be coming off shortly, we didn't take the time to fab in an X- or H-shaped crossover. This should be considered a must for any dual exhaust system as a properly placed crossover will not only make the car sound better, but will increase both horsepower and torque, usually by at least 10 in both categories.
Allow for a couple of extra...        read full caption Allow for a couple of extra inches in the equation and cut. It's always better to measure twice and cut once.	Now that everything has been...        read full caption Now that everything has been cut and flared, it's all mocked up to ensure a perfect fit. You can also see how well this pipe bends around the axle and off to the side. The only tweaking that will have to be done is about an extra foot or so added for the exhaust tips.	Now that one side is measured,...        read full caption Now that one side is measured, cut and bent, the Dynomax mandrel bent tubes are flared to fit onto the mufflers.
And finally the other side...        read full caption And finally the other side is measured cut and bent. Harrison preferred to measure each individual piece rather than make a couple pieces off of one measurement.	Rather than reuse the old...        read full caption Rather than reuse the old hanging brackets, new brackets made from heavy gauge steel with rubber bushings are used.	Notice that you can't see...        read full caption Notice that you can't see the exhaust system hanging down on this Monte. That's all done according to design. There is nothing worse than seeing an exhaust system hanging several inches below the vehicles frame.