Is it possible to take a N/A 5-speed chip and modify or add to it to have evrything needed for a turbo chip?
Sure. The MEMCals are the same (IMO) and if you want to save the .pcm file from the stock N/A 5-speed chip and then add what is missing from the TGP chip to make it work for a Turbo car. There was 100+ differences in the 1989 SE GP 5-speed donor car chip and my 1990 TGP chip, but it can be done. Use TunerPro RT program to compare your TGP chip and the stock 5-Speed chip...there are a ton of interesting differences in there... 8)
I don't have the equipment to do any chip work so I don't know how far I'll go with it. Wonder if Mick wants to make some money?
But you'd be willing to help me through it? That's if I can get the equipment.