Project LS9TT Part One: The Components

Making big power is cool. But making big power with a twin-turbo engine? That might be the coolest.

That’s just the assignment Chevrolet Performance engineers Vince Tiaga and Dave McKenna recently received when they were asked to upgrade a standard LS9 long block. However, they had to do so in such a way that an enthusiast might be able to replicate the project in their garage. The result was the LS9TT.

“We were tasked with coming up with a package to kind of just exploit the potential of the hardware we had from the LS9,” Tiaga explains. “Really the thought process was [to do so] trying to use parts that the everyday consumer is able to get their hands on.”

The duo targeted 1,000 horsepower, not a bad outcome for a project in which the LS9 service long block was to be left relatively untouched. For reference, the supercharged LS9 crate engine once offered by Chevrolet Performance was capable of 638 horsepower and 604 lb.-ft. of torque.

Of course, with the LS9 being designed for boosted applications, turbos needed to be part of the package. Tiaga and McKenna utilized Borg-Warner EFR-7163 turbos, an off-the-shelf option that is the largest small-frame turbo available from the company. They were directed to use that frame by leadership to try to implement the smallest package possible. Borg-Warner has a long relationship with Chevrolet, and in fact provides the turbos for the Bowtie’s NTT INDYCAR SERIES engines, so it only made sense to utilize the brand, which itself was enthusiastic about the potential to gather new data for projects going forward.

Tiaga and McKenna added JEGS brand stainless steel 1 ⅞” turbo headers, a stock LS3 intake system and set up a Holley ECU to control it all. Mobil 1 15W-50 advanced full synthetic oil provided the lubrication.

Just as Borg-Warner has a relationship with Chevrolet through the INDYCAR program, so too does Holley with the brand thanks to each COPO Camaro utilizing Holley EFI. However, that wasn’t the only reason it was selected.

“Holley is very popular with the LS engine swap crowd,” McKenna says. “[This one] is not a full race-type engine controller, but it comes in at a very reasonable price point for the capability, so it’s something that I think would mimic what the average Joe would do in their home garage.”

The 1,000 horsepower target was the starting point for how Tiaga and McKenna built the engine, which first led them to turbo sizing. Once they understood their capabilities, they moved on to sourcing headers and how they would be attached to the turbos. They note that everything grew organically based on what they felt would be the best next steps, using stock hardware and easily accessible parts, be it through a local auto parts store, catalog or online distributor.

“All of the hardware was accumulated and then installed in a manner that was relevant to the story of the engine,” Tiaga says. “Everything looked and felt kind of how somebody would actually do it in the real world.”

Tiaga works in Engine Hardware Development and has managed both the Cadillac and Corvette Racing programs. McKenna meanwhile is the Lead Combustion Engineer for Performance and Racing Programs and has also been the COPO development engineer for the last three years. Each has seen the pinnacle of the racing world, but remains excited about their LS9 build for its simplicity and proof of the horsepower possible despite a limited budget.

“I think a lot of people were surprised about the capability of the hardware and I don’t want to confirm any projected numbers, but I’ll say that these results are the tip of the iceberg,” McKenna says. “I think there’s still quite a bit more left in the combination with some pretty minor changes.”

Many in the performance world will be watching closely.

Stay tuned to The BLOCK to learn about the performance numbers achieved when the engine hit the dyno at the GM Performance and Racing Center in Pontiac, Michigan.