Last month, we learned from a leaked GM internal service and parts operations document that an upcoming Corvette would see a new engine coded as the LT5. The engine is described as a 6.2-liter DOHC V-8 with direct injection, variable valve timing, and using an aluminum block. It is likely bound for the next generation Corvette ZR1 and/or the mid-engine Corvette.
However, as we’ve already seen the Z06 and its supercharged LT4 V-8, we guessed that the upcoming ZR1 would likely use some form of forced induction to top the Z06’s 650 horsepower rating. Yet, nothing in the document made any mention to turbochargers or superchargers. Forced induction now seems extremely unlikely as the upcoming ZR1 has been caught on video testing at Mazda Raceway Laguna Seca and it definitely doesn’t sound boosted.
From the brief clips, we get the ZR1 prototype accelerating with what sounds like three-quarter throttle down Laguna Seca’s legendary corkscrew. There’s no turbocharger hiss or supercharger whine, which you can hear clearly later in the video as a Camaro ZL1 1LE rolls through the same corner.
What also is interesting and leads us to believe that this might be the LT5 DOHC V-8 is the tenor of the exhaust note. While it’s hard to distinguish without full throttle and looking inside the Corvette’s engine bay, it doesn’t exactly sound like Chevrolet’s standard OHV small-block V-8.
What we also see in the short video clips is that Chevrolet appears to be testing the upcoming super sports car with both a small and large rear spoiler, possibly hinting at an optional performance package.
Current rumors peg the upcoming 2018 Chevrolet Corvette ZR1 rated with 750 hp. However, as it appears that Chevrolet isn’t using forced induction, and previous generations of the ZR1 were the highest powered Corvettes, we’re left wondering if the company will keep with tradition or essentially swap the Z06 and ZR1 monikers? It doesn’t seem likely we’d see a 750 hp naturally aspirated engine, but hey, anything can happen — maybe Chevrolet will surprise us.