Smitty, our all-knowing advisor, told us that custom exhaust systems are something he would only do with two guns to his head. However, it’s too late to save us – we’ve already started.

The way the stock exhaust for our engine was routed would put the headers outside the envelope of the chassis, scraping against the ground when we drove. This was unacceptable, so we designed a new exhaust routing system. To design this, we used the CAD drawings of our chassis and engine to create the paths for four exhaust headers that were of equal length, and tuned to be resonant and efficient at the engine’s peak RPM.

This is easier said than done.

When we began manufacturing the exhaust design, we were reminded of the loose tolerances that we can expect from hand-manufacturing. Because our pipes were made of stainless steel, the chop saw blade in our shop was unusable, and we resorted to using hacksaws and grinding wheels. This is the most primitive and inaccurate method of manufacturing, and the only one available to us.

In fitting the straight and curved pieces that we had cut out, we realized that the hand-cut pieces fit nothing like the CAD dictated. As a result, we scrapped the shiny, perfect design, and shaped and hammered the pieces so they fit.

In fitting the 3-7 pieces of each exhaust header so that they all fit inside the envelope and ran into the collector, we realized exactly how painful the process was. The most effective method that we discovered was to hold all of the pieces in place, and mark the alignment with a marker. We then tacked the pieces together separate from the engine, and fit it onto the engine, bending and breaking tacks as needed.

By Harrison Lu, Racecar Savage