A conservative ECU setup by Chevrolet appears to be the cause for the power loss some 2015 Corvette Z06 owners say they are experiencing after heavy use on the highway or the track.
Some people thought the power loss might be caused by a heat soak problem, which is caused by the buildup of heat in the engine compartment after several full throttle runs. This heat cuts the efficiency of the supercharger because hot air has reduced oxygen molecule density, meaning less fuel will be burned.
General Motors responded to a request by Auto Evolution with this explanation for the power loss:
“We are confident that the vast majority of customers are going to be more than satisfied with the performance the Z06 offers in stock form. For those that want more power, they can visit an aftermarket tuner – who are not held to the same standards [emissions and warranty] as an OEM. However, this presents significant risk to the customer. An aftermarket tune voids the vehicle warranty as Chevrolet cannot possibly test or confirm the durability of their calibration; and aftermarket calibrations could cause drivability issues that are not present in the factory setting.”
So it appears that Chevrolet is just trying to make sure the Z06 has reliable power for as long as the warranty is in effect.
Vengeance Racing took delivery of a Z06 last week and says it doesn’t believe the problem is a heat soak issue. In fact, in a post on Corvette Forum, the tuner says it experienced the same power loss with the OE calibration.
“The timing tables are EXTREMELY conservative and the ECU will pull timing for almost any situation,” Vengeance wrote in the post. “I am waiting for owners to complain about ‘tip in’ as the ECU pulls a massive amount of timing when slightly touching the gas pedal.”
While that explanation sounds good on paper, if I had just handed out $100 grand for a powerful Z06, I think I’d want to be able to drive it as much on the track as I wanted – without having to worry about any such power loss.