GM has still been a little flaky when it comes to the full performance of the new mid-engine , likely because there’s still plenty of testing to be done. But a forum member was recently shown an engineer’s book full of secrets, including a quarter-mile time.

While the photos over on look like they could be legit, it’s hard to know for sure if this user’s story about a GM engineer letting them take pictures of preliminary performance figures for a car as hot as the C8 is true. We’ve reached out to Chevy to try and confirm.

If the figures are real, then it’s likely we’re looking at numbers for the base C8 Corvette considering the listed top speed is 193 mph, which was . Reportedly, optioning for the Z51 Performance Pack actually lowers the C8's top speed, due to the increased downforce of the additional aerodynamics parts.

So, if all of that is true, then this engineer’s book would suggest the base C8 Corvette has run a quarter-mile time of 11.3 seconds hitting a top speed of 121 mph. That time is comfortable nestled between the 12 seconds it took the C7 Corvette with the Z51 performance pack, and the 10.95 seconds it took the C7 Z06, according to .

The sheet also tells us the max lateral g-force of the base car was 0.9 g, and 1 g with the Z51 pack optioned. We also get a peek at the drag coefficient, which the book lists as 0.32, a 3,535 lb curb weight for the coupe, a 3,577 lb curb weight for the coupe with the Z51 pack, and a 3,637 lb curb weight for the convertible.

Stopping distance from 60 mph to zero was 115.1 feet on the base car, or 108.4 feet with the Z51 pack. There’s also some random but fun specs, like its 18.5 gallon fuel tank.

Again, all of this seems like preliminary testing—so all of this is subject to change when or if Chevy decides to officially announce any quarter-mile times or stopping distances. And all of that is even dependent on this booklet being real. If it is, it’s pretty cool of that engineer to open the book on the car for its fans.