When changing to LED turnsignals, the OEM flasher may hyperflash at 2x the normal rate, and the tachometer turnsignal indicators may not flash or flash together.
If either happens, you need to replace the flasher with EP26. EP26 LED-compatible flashers by Novita/Tridon do not activate the C2 pin which Porsche uses to power the common connection of the tach turnsignal indicators.
This EP26 module is modified to ground pin C2 so the tach turnsignal indicators work properly.
EP26 LED-Compatible Flasher for 911 up to '84; 70-73 914