I used to dump the clutch while revving up and my car would launch while burning rubber but now it won't launch anymore and the car feels slower what could it be that happend?

From a stop the car accelerates slower than normal, the gears shift normal it doesn't sound nor feels like clutch slippage

Ok, Any sputtering, jerking, stalling, vibrations, or anything out of the ordinary besides slow acceleration? Have you noticed any difference when starting the engine in the morning? Starting after a drive? Any rattling, grinding, clinking, etc from the rear end? If the engine always runs smoothly, I would not point to the fuel system, since fuel issues would result in some sort of bucking or sputtering, especially at full tilt from a stop. Now this is a very cleanly made engine control system, so diagnosis should not be too difficult, but you will want to have at least a digital multimeter or the OBD-1 dongle for the car and something that can access the motronic control module (scanner or software). Before you get into testing the engine control systems, you should certainly run a compression test and leakdown test on all cylinders, ensure the sparkplugs are in good condition, and make sure there is dielectric grease on the spark plug terminals to eliminate those simple things. Another thing, Beaumont being right next to Houston, did this get any water damage during the storms?