The 2015 Chevrolet Corvette Z06 has only just begun to ship to customers, and already owners are reporting power loss from spirited back-to-back highway and track runs.
The tendency for these owners is to point a finger toward supercharger heat soak, but the true cause is much more benign: conservative Engine Control Module (ECM) tuning.
Heat soak is a phenomenon whereby thermal energy produced by demanding engine use heats the supercharger and, by extension, the intake charge. Not only can this reduce power because of the reduced air (oxygen) density, but it can also lead to detonation, or pre-ignition.
But as our friends at Autoevolution report, tuning group Vengeance Racing did back-to-back dyno testing on their own car and found the intake charge temperature to be impressively cool. Instead, they say, the issue lies with a (perhaps overly) safe ECM tune, which pulls timing long before it has to. This not only helps prevent any chance of detonation, but is also essential for the Corvette Z06 to meet its emissions goals.
Autoevolution reached out to General Motors, who seem to verify what Vengeance Racing has claimed, saying that while they “are confident that the vast majority of customers are going to be more than satisfied” with the stock engine mapping, those who are not can try the tuning aftermarket. But the manufacturer cautions that changing the engine tune will void the warranty, and may lead to driveability and reliability issues.
At the end of the day, it’s simply important to remember this: the 2015 Chevrolet Corvette Z06 is a ripe peach of a track day car, but it’s still EPA-tested, and warrantied for 10 years/100,000 miles. Some performance throttling should be expected.