Twin-Turbo C8 Pumps Out 736 WHP With Proprietary Tune

With just 7.5 pounds of boost and with a prototype piggyback computer, this twin-turbo C8 makes big power.

So far, the C8 Corvette has proven to be a tough nut to crack thanks to its ECU, which GM purposely designed so it was tougher to hack. Regardless, as it always does, the aftermarket continues to try to break through so that we can unlock the C8’s true potential. We’ve seen a handful of twin-turbo C8 builds lately, but all of them are running low boost with the stock ECU. But now, Extreme Turbo Systems appears to have created some sort of workaround with their own twin-turbo C8.

ETS has given their twin-turbo C8 a handful of upgrades, including its pair of huffers putting out a modest 7.5 pounds of boost. They’ve also given it intercoolers, a high-flow intake, methanol injection, and a custom exhaust. But the most interesting aspect of this build is its “proprietary tuning solution.” Thankfully, ETS explained this a little further in the comments after someone asked for clarification.

“The car is tuned via a prototype piggyback computer and auxiliary fuel system. Currently, the kit in development plugs into the coils, MAS, MAP, and O2 sensors. This system keeps the stock ECU happy while allowing us to run in boost with controlled ignition. The additional fuel comes via auxiliary ethanol injection. Currently, the car overpowers the clutches and is why we dyno in 4th gear. 5th gear is too long and the clutches slip. Street manners and driveability remain stock, but now the car has much more power.”

Others have suggested the idea of using a completely new, custom-built ECU in the C8. So this is not really a surprise. But it is an interesting alternative to tuning the stock ECU that seems quite promising. It might also currently be the most powerful C8 on the planet. The rather mild setup managed to lay down 736 horsepower and 669 pound-feet of torque on the dyno.

Of course, this is only the beginning. Lots of others are working on cracking the C8’s ECU, and a few are also building twin-turbo C8 Corvettes. Hennessey was the first, of course. East Coast Supercharging is currently refining its twin-turbo system, waiting for the ECU hack. And Late Model Racecraft is currently building one for YouTuber Street Speed 717. But if one thing’s abundantly clear from Extreme Turbo Systems’ build, it’s that the C8 is capable of making serious power. Even if tuners never manage to crack the car’s ECU.

Photos: Extreme Turbo Systems

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