ok, heres my understanding of the whole "obd" business.
there is obd0 obd1 and obd2.
obd0 would be on i think any car before 1991, obd1 would be til around 95, and obd2 from then on.
obd reffers to the electrical system used in a car ie. the ecu and other ocmponents that control the cars functionality. the reason that you would have to convert a car to obd1 from obd2 to run a turbo setup is because the ecu's are far less complex and they are supported for chipping. now, the way you go about converting a car to obd1 or even obd0 (if your car was obd1) is by buying a new ecu and a new harness.
a harness is what plugs into the ecu from every single wire in the car that controls soemthing.
harnesses normally run about 70-100 dollars and come in many verieties. if you are a good electrician you can make your own fairly easy, but you need some good soldering skills.
the next part, and most important is the ECU. the ECU obviously is what controlls the cars functions. on our cars, the ecu is already preset to do things a certain way, but once you introduce the tunability of the ecu with something such as hondata, you are able to modify things. this is where you hear people mentioning taking off the speed limiter on the car. its all in the ECU.
if you are going to run a turbo or forced induction system on your car, one of the best things you can do is run a chipped ECU. for us accord owners, the ecu of choice is a P28 which i beleive is from a civic, although it could be from a teggy.
now once you have your ecu, it needs to be chipped, as you would with a games console, so you can modify setings. there are a few different types of tuning software you can use: chrome, hondata, uberdata (a copy of hondata), NepTune etc etc...
for my car, im using NepTune, a fairly new system for tuning. since i am not doing a transmition swap and i am looking to build a car for luxury and fun not for high speed, i will be keeping my stock auto tranny, until it dies when i will be getting a new one from Dr. Evil transmisions. anyway... neptune lets you tune he shift points, rpm limits, stall speeds and other vital settins on an automatic transmition, whereas most other tuning software will not.
anyway, once tuned to your needs, the ECU will have a map of the fuel/air ratios and other such settings. Of course with forced induction, the more air you push into the engine, the more fuel is needed. this is the job of a tuned ecu. although saying that, companies such as Apexi offer something called an AFC which manages the fuel injectors from a little computer in your car, mounted on your dash.
i hope that makes things a little more clear as far as what obd0,1 and 2 is. as i said, i am not an expert, and i dont claim to be, but this is what i know from the research ive done into my turbo setup.
if i can offer some advice to you for your kit... dont buy a kit if you ca help it. i am spending about 3500 on my whole setup, and that includes all parts, all the tuning, all the computers including an ECU, conversion harness, boost controller and injectors. its easy to get confused with all the different parts out there, but if need be, i can give you all the stuff that ive compiled and learned from as far as turbos go. its not as easy as it sounds becasue a turbo isnt a bolt on. once you modify what goes into the engine, you are going to be more likely to go wrong when you set up everything.
just sit down one day and search google for "installing turbo on..." and read up how to do a turbo install on ever car you can find. ive read how to do a twin turbo on a 5.0 mustang and even how to do a manual boost controller on a DSM. its all useful and it all helps you choose the right stuff.
good luck and feel free to either PM me or just pst here if you have a question(s) for me, ill gladly help you if you really want to do a turbo setup.
