Well, I recently swapped an 2016 L83 into an 05 RX-8 with a T56 trans. It's a stock engine with Camaro intake/exhaust manifolds for fitment. The car has been tuned and idles, runs, and pulls pretty good at WOT for a stock truck engine but the everyday driveability (or lack thereof) is what's killing me.
For whatever reason, I'm having a lot of rev hang in between shifts. I either have to drive like an 80 year old and let off the pedal completely until the engine starts to decel before pushing in the clutch in order for the revs to actually drop once the clutch is pressed in. Also if I shift hard and quickly enough it also isn't noticeable. Not being able to drive this any way in between without pretty noticeable rev hanging is super annoying. Depending on gear and RPM the car is more or less hesitant to decel and sometimes it takes 3-4 seconds before it'll start to decel. The tuner still hasn't been able to figure out this issue.
I originally had a 2016 silverado ECU that came with my swap, rev hang in neutral was atrocious. I heard that reflashing to corvette manual OS would fix the problem so I did, but it only improved slightly and I thought the ECM's OS might have been corrupted or not completely overwritten. Then I decided to get a fresh ECU with a 2014 Corvette manual tune and it's still there. Long story short, I now have 3 HPtuners licenses at this point for this car and I still haven't figured out the rev hang issue.
When logging, when I lift off the pedal the pedal value bottoms out, but commanded throttle doesn't follow, it lingers in the 15% range before dropping.
It almost seems like something with driver demand torque, but i started with the values for a stock corvette which wouldn't have rev hang issues so I would assume those settings should be fine. Has anyone else run into this issue or a similar issue with a manual Gen 5 swapped car? At this point i'm starting to think my car is haunted.