I am not an expert but I will give it a shot, the Turbo link, Scan master, Direct scan etc. They are all pretty much a scanning tool which means they will tell you what your readings are like O2,BLM,TPS, etc… They all read of your factory ECM, some of them via the ALDL port and some others you need to need tap/solder wires to your factory ECM to get the reading via a laptop computer. Scan tool like T Link and Direct scan requires a lap top, scan tool like the scan master has its own display screen.
Now Bigstuff , Fast, XFI etc, they are stand alone computers that replaces your factory computer. They come with a pig tail harness adaptor that let you plug into the factory ECM harness so that you can read the factory sensors. The most of the stand alone systems will give you the capability of running a wide band O2 sensor so that you are able to tune the car for the proper Air/Fuel ratio. You are also able to change the injector pulse for more/less fuel. Add or subtract timing etc, data log your runs etc. They are far advanced now days that it can do so many things that factory ECM can’t do. Of course you need a lap top for the initial installation of the start up program, read out, and make correction to your programs. You need a permanent lap top in your car so that you can always look thing over. Once a good program is in and tuned properly you can put the Lap top away but I like to see it in car so that everything is accessible just incase.
I will say go for the Power logger form Full Throttle Speed, it’s awesome and very advanced than anything out there. I am very impressed with its capabilities.
HTH
Prasad
