Pushing the Limits of LSA Engine

This project began after multiple customers who owned GM or Levitator LSA engines reached out to us requesting us to increase the power of their engines.

- David Hartz

For those who may not be familiar with this engine, the LSA is a reliable and robust 6.2L supercharged LS motor developed by General Motors. Many marine companies have adopted it due to its proven reliability and its ability to generate substantial horsepower.

However, as with any engine that burns gasoline, enthusiasts often seek ways to increase performance. With that in mind, this article will take you step by step through the improvements we have done for customers, along with the testing we've conducted on factory LSA motors.

Water Thunder Performance has conducted hundreds of thrust tests over the last 15 years on various combinations using our thrust dynamometer. We have logged a tremendous amount of data, tuning and severely testing every Water Thunder engine on our thrust dyno, before delivering them to customers. We have a lot of thrust data for various horsepower levels, allowing us to compare the LSA platform both in stock form and modified forms to other known engine combinations.

Recently, one of our customers, who owned a Levitator LSA motor, required a ludicrous amount of power, so they upgraded to one of our 416 CUI stroker motors. It featured a 3.0L Whipple supercharger capable of producing over 950 horsepower on pump gas. Fortunately for us, we can utilize his trade-in for this article.

To begin the process, we removed the small factory electronic throttle body, the factory ECM and wiring harness, (on left of pic 1) and replaced them with a larger 92mm throttle body and a standalone Holley Terminator X EFI system (on right of pic 1). After making these initial modifications, we installed a 2.68 ratio Ox Box and mounted the engine on our thrust dyno.