C8 Corvette with Custom Exhaust Roars on the Dyno
The first people who ordered a 2020 Chevrolet Corvette Stingray have been receiving them over the course of the past six weeks or so. While the C8 sounds good in stock form, it is no surprise that owners are going to want to upgrade them, so aftermarket companies are already hard at work developing performance upgrades for the first mid-engine Corvette.
One of those companies is Late Model Racecraft. Their team recently created a custom cat-back exhaust system followed by a set of custom high flow catalytic convertors. After designing and installing these parts on a white 2020 Corvette Stingray, they loaded the car onto the dyno to see if the aftermarket exhaust upgrades add performance, or if they just add sound. As it turns out, these exhaust upgrades add a surprising amount of power, even without an engine tune.
The Locked LT2
Before getting into the videos showing the 2020 Corvette with aftermarket exhaust bits, we should remind you all that the LT2 engine computer system in the new Stingray has not yet been “cracked”. This means that tuning shops cannot yet make adjustments, so any power output gains are being seen with just the stock engine tune. Of course, with added air flow on the intake or exhaust side, the computer does self-adjust a bit, leading to more power without any external tuning.
Once tuning capabilities for the C8 are unlocked, we are all-but-certain to see exhaust systems, particularly those with high flow catalytic convertors, lead to bigger power gains, but for the time being, the untuned results are pretty impressive.
LMR C8 Corvette Cat-Back Exhaust
First up, the Late Model Racecraft team created a cat-back exhaust system for the white C8 Corvette. They removed the stock system, including an array of valves and the big, heavy muffler setup and replaced it with gorgeous curved custom piping, inline bullet-style mufflers and big, round exhaust tips. Of course, removing the bulky muffler and the exhaust valves make this Corvette quite a bit louder, as you can hear in the video below.
More importantly, the custom piping adds some power. In stock form, this Vette made 458.27 horsepower and 400.88 lb-ft of torque at the rear wheels during a fourth gear pull. With the LMR cat-back exhaust, a similar fourth gear pull lead to 458.11 horsepower and 422.39 lb-ft of torque at the rear wheels. While the peak horsepower number is more or less unchanged, the torque improvement of roughly 21.5 lb-ft is significant. Better yet, on a fifth gear dyno pull with the LMR exhaust, peak wheel torque jumped to 438.3 lb-ft while horsepower was up slightly, to 459.16.
In short, this aftermarket cat-back exhaust system added close to 40 lb-ft of peak torque and a few peak horsepower at the wheels, but more importantly, the system adds as much as 20 horsepower through the middle of the power band. When we talk about horsepower and torque numbers, we almost always focus on peak numbers because those are the most impressive figures, but this exhaust system doesn’t just improve peak power, it shifts the power upwards throughout the entire pull. This means that you don’t just gain power on the top end; the C8 Corvette benefits from this exhaust setup in the mid-range, where most drivers will use it the most.
High Flow Cats
Next, LMR designed a set of high flow catalytic convertors for this white 2020 Corvette. After installing them, they loaded the car onto the dyno to see how much impact these pieces add. The shop did a baseline pull with the cat-back system and the stock cats, getting numbers of 458.4 horsepower and 437.92 lb-ft of torque at the wheels. With the aftermarket cats, those numbers jumped to 467.79 horsepower and 447.93 lb-ft of torque.
While this is not the cleanest comparison, if we look at the original dyno numbers from this C8 prior to any exhaust work being done and compare those to the numbers with the cat-back system and the high flow cats, this C8 Stingray gained roughly 10 horsepower and 47 lb-ft of torque without any other changes to the vehicle.
Most C8 Corvette owners will buy an aftermarket exhaust system for the added sound, but those who do will also enjoy a healthy increase in power that can be enjoyed from a stop all of the way to top speed.
Patrick Rall is a professional writer and photographer with a passion for all things automotive. Patrick has been sharing his automotive expertise in automotive journalism from Detroit for more than a decade covering the Big Three. Having grown up in his father’s performance shop, he spent extensive time at the oval track and drag strip – both driving and wrenching on various types of vehicles. In addition to working as a writer, Patrick previously worked as an automotive technician before moving on to a business office position with a chain of dealerships, and this broad spectrum of experience in the industry allows him to offer a unique look on the automotive world. Follow Patrick on Youtube and Twitter.