DIY exhaust projects do not have to be fancy to be fun—or to sound downright nasty in the best way. In this build, a set of cast-off Borla ATAK mufflers, leftover 3-inch Corvette exhaust tubing, and a few marketplace mandrel bends turned into a custom “Franken-exhaust” with handmade oval tips that completely transformed the car’s tone.
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From Cobbled Turndowns to Custom Borla System
The starting point was a well-used, cut-and-spliced system: FlowPro Max mufflers feeding into basic turndowns. It worked, but it didn’t sound great and definitely didn’t fit great. The goal was simple:
- Reuse Borla ATAK mufflers from a C6 Z06 kit
- Reconfigure the 3-inch tubing to fit the chassis
- Build low-profile oval exhaust tips that wouldn’t snag on the trailer or look out of place under the quarter panel
The original big, shiny round tips were a non-starter—they’d already hung up on the trailer once. That’s what kicked off the idea of building oval exits tucked tight to the body.
Making Oval Exhaust Tips from Round Pipe
The coolest part of this build is how the tips were made:
- Start with a 10-inch length of 3-inch round pipe.
- Mark centerlines and layout cut lines using a welding table, blocks, and a marker for consistent height.
- Split and partially crush the pipe to begin forming an oval shape while keeping roughly the same cross-sectional area as the original 3-inch tube.
- Make pie cuts along the sides, flex the metal outward, and test-fit until the opening is the desired size (around 2 3/8 inches tall by about 4 3/4 inches wide).
- Fill the resulting gaps with shaped sheet-metal inserts, weld everything solid, then grind and sand until smooth.
The result: a pair of nearly matching oval tips, ready for high-temp paint so they visually “disappear” under the car while the sound does all the talking.
Fitting, Welding, and Hanging the System
The mid-pipes and mufflers were mocked up one side at a time—cutting back old welds to save as much tubing as possible, then joining mild steel to stainless (yes, it can be done) with careful MIG welding. Small adjustments in length and angle brought the tips exactly where they needed to be: just behind the rear wheel, tucked close to the body, and with a finger’s width of clearance to the frame.
New hangers were added using nutserts and rubber isolators, giving the system solid support and a little flex without rattles.
The Payoff: A Rowdy but Refined Sound
Borla ATAK “race bullet”–style mufflers are designed to knock just a few decibels off open pipe while dramatically changing the tone. The finished system is only slightly quieter than straight pipe, but with far less rasp and a much cleaner, deeper note. It’s aggressive, unique, and exactly what a home-built custom exhaust should sound like.
Most importantly, this project proves you don’t need a mandrel-bent, pre-engineered kit to build something awesome. With a welder, a grinder, some patience, and a willingness to experiment, you can create a one-off exhaust that fits your car, your style, and your budget.
Thinking about building your own exhaust? Grab some scrap, start cutting, and improve with every project—the next one will be even better.
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