Let me begin by saying I have been driving the car flawlessly for months. I recently had an RPM transmission installed with a solid coupler in the rear and DTE diff brace. I also have an RPS clutch in the car right now. No vibrations or weird noises until last night.

I took the car to the track last night on street tires and launched gently, I got minor wheel hop 1 time but nothing more. All shifts were clean..no grinds, no clutch sticking to floor nothing. I get in the car to make another pass after cool down and when I let off the clutch to go forward the car makes this moaning noise. I stop and do it again, same thing. I then took it out of gear and just pushed the clutch in....no noise now. I put it back in gear and move forward again and the noise is back.

After driving it back home I checked the clutch fluid (which was dark) and did the turkey baster method to clean it....drove the car again and moan is still there. I can sit with the car out of gear and pump the clutch and get nothing. I put the car in gear and move and it moans, however when you shift into the other gears I get no noise at all. It only does it from a dead stop, once it's moving it doesn't ever do it unless I am downshifting while rolling and I can kind of feel it and hear it....I can feel it in the clutch pedal when easing off the clutch from a stop every time. Does a master make a noise when it's going out? Could it be drivetrain related? I am totally stumped.