1990 RX-7 Clutch Slipping
 

Hey guys, I recently got my car out of the shop, Eunos Custom Automotive (Mazda/Rotary Specialist), but now the problem is, the clutch is slipping, we drove the car home, but the whole way, we weren't able to give it any power, the second you begin to press the gas a little harder, the engine revs, but the car will not gain speed. We called the mechanic when we got home, he told us that when he test drove it, it was fine. Any help would be greatly appreciated, thanks guys.

Perhaps you have a clutch fluid leak somewhere? Check the clutch fluid reservoir to see if its low or leaking somewhere? But that would usually mean you wouldn't be able to put it into any gear. I'm not too sure. :( Sorry I suck. :(

You could also check if you have air in your clutch fluid lines or perhaps its a bad master clutch cylinder or bad slave clutch cylinder. You could try flushing the clutch fluid out, refill and try driving again?

I'm not too sure if fluid leaks will lead to a slipping clutch, usually when most people have a slipping clutch its because its worn out.
I remember from my Honda Prelude when my clutch was slipping it was due to the clutch pedal not being properly spaced out. The clutch was not disengaging properly. But I'm sure your issue is completely different.
Sorry :( just trying to provide as much info as possible to help you out.

EDIT:
If the mechanic recently replaced the clutch or flywheel perhaps you should bring the car back regardless of the fact that he said its fine. Maybe he didn't install it correctly or something? I dunno :(

check to see if your clutch slave is leaking.
what work did you have chris do?
anything related to the powertrain?

Make sure the clutch pedal is adjusted correctly and make sure there's no air in the system

thats the thing. it wouldn't slip if that were the case, you wouldn't be able to disengage the clutch. he's saying the clutch is slipping under load.