Cadillac CT4’s Engine Created a “Torque Monster”

(This is from GM’s Pressroom by Stefan Cross at GM Product communications 6/25/2020)

2.7L Dual Volute turbocharged engine is a unique option for a high-performance sub-compact luxury sedan.

Offering segment-leading torque was not an accident. For the 2020 Cadillac CT4 engineering team, it was a priority. There are numerous factors that contribute to the CT4’s outstanding performance, including its rear-wheel-drive-based architecture, transmission and near-perfect weight distribution. However, the main contributor to the car that the Cadillac engineering team refers to as a “torque monster” is its unique engine.

A dual volute 2.7T engine is standard in the CT4-V (325 horsepower and 380 lb.-ft. of torque) and available in the CT4 Premium Luxury (310 horsepower and 350 lb.-ft. of torque) 1. The engine was originally developed as a clean-sheet design for GM with first use in the 2019 Chevrolet Silverado and GMC Sierra. But from the beginning, this engine was also planned for Cadillac’s new sub-compact sedan as well. And for CT4, what is under the hood is much more than a truck engine.

The 2.7T engine benefits from low mass, without compromising output. For example, the Cadillac 2.7T engine provides higher horsepower (+5 horsepower) and torque (+65 lb.-ft.) than the famed Cadillac Northstar V-8 engine of the past, but weighs 140 pounds less. The dynamic benefits of the 2.7T engine’s output, performance and low mass create a significant advantage in the vehicle’s ride and handling.

Furthermore, the engine reaches peak torque at only 1500 rpm in the Premium Luxury – 1800 rpm in the CT4-V – and stays there until 4000 rpm with a very gradual drop-off later in the rpm band. This allows the CT4 and CT4-V to respond and accelerate faster across the rpm range and hold gear at lower engine speeds. Other, high-revving, low-torque engines require down-shifting gears, which takes extra time and can create turbo lag during acceleration.

A volute is a spiral chamber that circulates exhaust air through the turbocharger to drive the turbine. The dual volute engine features two chambers stacked on top of each other – sending air to both sides of the turbine,  spinning it quicker and more efficiently. Each chamber is integrated into the exhaust manifold, attached directly to the engine’s cylinder head, which recovers heat for faster engine and transmission warm up, along with quicker turbo response.

“The benefits of the CT4’s dual volute turbo engine are very noticeable on a track or on your daily drive. The engine harmonizes very well with the independent suspension, available limited slip differential and driving controls to provide exceptional levels of enthusiasm,” said Dave Schmidt, Cadillac CT4 lead development engineer. “The car delivers the torque of a V-8, while providing the efficiency and vehicle balance of a smaller and lighter engine.”

The 2.7L Turbo also features a three-step sliding camshaft design that allows for Low lift optimized for fuel efficiency, High lift optimized for performance and Active Fuel Management for maximum fuel economy. Both the dual volute turbocharger and three-step sliding camshaft are segment firsts.

This looks to be a wonderful option, I cannot wait to try one.


Looking Back a bit

For many years you know I was a traveling salesman for the Protectoseal Company out of Bensenville, Ill. There we sold fire and safety equipment for handling flammable liquids and solvents to industry. This was a great company to work for, as they tried to do everything “First Class”.

In those days there were plenty of manufacturers to call on, and my territory covered two Provence’s of Canada, All of New England, Upstate NY and a corner of Pennsylvania. Needless to say I was on the road all the time. That lead do my having to leave the company for family reasons.

Due to the nature of our product, I got to see how things were done. I called on tire manufacturers, Drug manufacturers, electronics manufacturers of all kinds large and small, Tire manufacturers, paint manufacturers, Oil refineries and GM manufacturing plants, a few Ford and Chrysler plants. Along with their suppliers. Since I had a Top Secret clearance when I was in the Navy, they trusted me and took me through and asked me what they needed.

I learned why tires need balancing when new. Mostly due to methods and lack of care, I learned that tires for Cadillac were x-rayed at the plant, and if they were not perfect were rejected, and sold to the consumer market.

I learned that the paint for Cadillac had the highest pigment, and was frozen then milled to the consistency of face powder before making the paint. For that reason it cost three times the paint for other cars.

I learned that making Premium unleaded gasoline cuts a third of the volume of Oil company productions, as they “crack” out the impurities.

I went to a 3M school in Minnesota to learn about masks of all sorts and descriptions. How they work and why. I called on Filter companies and saw the reasoning behind oil and air filters.

I learned the secret to the 100mpg carburetor for cars. Yes it is possible, it is not a myth.

I called on Stamping plants that made Fenders for cars, and learned why they rust.

All that knowledge stuffed into my brain, lead me here to sell Cadillac Automobile. There is a difference.

I will try to share some of that knowledge as we move forward.