Detroit, MI — Stellantis’s SRT performance division is working on a new technology designed to improve turbocharger response. Called eBoost Air, the system uses an electric compressor to significantly reduce turbocharger lag, particularly at low engine speeds.
Still at the prototype stage, the technology has been paired with an experimental version of the High Output 3.0L Hurricane inline-6 engine. However, Stellantis has not specified whether the eBoost Air system is destined for a specific production model.
Auto123 is at the Conner Center in Detroit, Michigan this week to attend the technical presentation of this new technology. SRT used the occasion to deliver a first look at the eBoost Air system, and they did it using a Jeep Grand Cherokee prototype.
Since the introduction of the Hurricane inline-6 engine, there’s been speculation about whether it could fit under the hood of the Grand Cherokee. If nothing else, this prototype, conceived and designed by SRT, shows that the powertrain is indeed compatible with the Grand Cherokee while maximizing output.
For the time being, the automaker has not disclosed its intentions regarding the commercialization of this potential Grand Cherokee variant.
An electric boost for turbochargers
The operating principle of a turbocharger is relatively straightforward. Exhaust gases drive a turbine that compresses intake air for the engine. By increasing the amount of oxygen available for combustion, the engine can produce more power.
A large turbocharger can move a greater volume of air and thus help increase peak engine output. On the flip side, it generally requires more exhaust gas to reach its optimal operating speed.
At low engine speeds, that energy isn't always available in sufficient quantities. This results in a brief delay between pressing the accelerator and the delivery of full requested power—a phenomenon commonly known as "turbo lag."
With the eBoost Air system, SRT adds an electric compressor upstream of the conventional turbochargers. When the driver suddenly requests torque and the turbos aren't spinning fast enough yet, the electric compressor temporarily boosts pressure in the intake tract. This pressure helps the turbochargers reach their operating speed more quickly. Once exhaust gas volume is sufficient to maintain boost pressure, an electronic bypass valve returns intake airflow to its standard route.
According to Stellantis, the transition between modes is intended to be seamless for the driver.
"By electromechanically pre-spooling the turbochargers before exhaust gas energy is available, we can significantly improve boost response and driving enjoyment," explained Tom Sacoman, head of SRT operations.
With the 3.0L Hurricane engine
To test the technology, SRT is using a High Output 3.0L Hurricane inline-6 engine. This twin-turbo engine is already found under the hood of several vehicles in the North American Stellantis lineup.
However, the automaker has not provided power figures or acceleration metrics for the prototype equipped with the eBoost Air system. Rather, the project's objective is to demonstrate that larger turbochargers, which favour top-end power, can be used without sacrificing low-end response.
SRT claims the resulting behaviour feels closer to that of a supercharged V8 engine, notably due to more immediate and linear power delivery.
Unlike a traditional mechanical supercharger, which draws a portion of its power directly from the engine, the eBoost Air system serves only to temporarily bridge the pressure gap before the turbochargers take over completely.
"When technology enhances performance without compromise, enthusiasts respond," said Tim Kuniskis, head of American brands and marketing for Stellantis in North America.
A rapidly developed prototype
Stellantis is also showcasing the eBoost Air system as a demonstration of SRT’s new development methods. The division claims to have progressed from concept to functional prototype in just a few weeks thanks to cross-engineering team collaboration.
Having officially returned to the forefront a little over a year ago, the Street and Racing Technology division is once again serving as Stellantis's performance laboratory.
For now, the eBoost Air system remains a concept. Still, the project demonstrates that the automaker continues to explore the partial electrification of its internal combustion powertrains, not only to improve fuel consumption, but also as a tool to enhance throttle response and performance.