Hey everyone, I picked up a '15 m7 z06 with roughly 32k miles from a dealer. It has a halltech intake, kooks long tubes with hfc, a LMR lower, and a green belt. No idea on who did the work or tuning.

During the test drive, it drove fine. Hammered it a few times with no issues. No idling issues or anything that stuck out like a sore thumb. So pulled the trigger and am now a z06 owner.

I decided to take it to a local speed shop that specializes in these cars along with other American muscle cars to get a baseline dyno and to have it "inspected" by specialists to see if the work on the car was done well. Car is leak free, only thing out of place was the clutch fluid reservoir was empty (face palm on me for not looking at that before I bought it). Filled it back up, did the ranger method a few times and strapped her on the dyno.

When he began the pull, the car sounded fine. In the upper rpms, maybe around 3700rpm you audibly hear the car struggle/plateau for a second and then the rpms continue to climb to red line. I've attached the crappiest photo ever of the dyno graph , from a computer screen. Made somewhere in the high 400s before power fell off from a slipping clutch the shop tells me.

Driving the car home, I put it in 4th gear and begin rolling on to the throttle to see if I can get the clutch to slip. I do notice that the car does not "pick up" like it used, but I don't know if I feel like it's a slipping clutch. Car drives normally 1-7th gear with normal dailying foot control.

I've owned some **** boxes (and still do) and normally a slipping clutch that I've experienced is when the rpms climb without the car actually picking up speed. Usually you'll get that burnt smell afterwards as well, but the Vette doesn't exhibit those symptoms.

So I write this essay to see if anybody has some insight on my situation whether it be the clutch, or a related part. Thanks for any help