I have a 96 audi a4 manual transmission on a 2.8 non quattro as a project car I was wondering if I need a new Ecu to support the quattro system or is it all transmission that does the work if someone could help me out I'd be very thankful

 

The quattro isn't controlled by the ecu on the b5's, but you're better off buying a car that's already quattro, as the structure of the two platforms are vastly different.

 

No offense but a FWD 12v V6 is possibly the worst A4 to have as a project car. sa9023 is right, it would be cheaper to sell that and get an A4 that already is equipped with quattro. **** I believe even the gas tank is a different shape on FWD vs quattro.

edit: The only worse one is a FWD 12v auto.

 

It will cost to 4 times what the car is worth to make this happen. There are so many seemingly insignificant parts that will need to be replaced that this project will nickel and dime you to death and even then it wont be as reliable as car built with the Quattro.

 

^ the gas tank is different; its in kind of an upside down 'u' shape to accommodate the driveline. OP, you definitely have waaaaaay more work ahead of you than its worth, both time and cost, to try and do this conversion, McGovs speaks a wise word: sell the 96 and pick up a 99 or 00 1.8t with quattro. It doesn't even have to be a pretty one or with low miles if you're making a true project out of the car and plan to do body work and rebuild the motor so a poor condition facelift B5 shell will run you relatively the same cost as you could sell the 96 for, give or take.

 

Your right but who's going to buy a fwd audi

 

Your car's previous owner found a buyer. You will too.

 

Someone will buy it that's how they got in the market in the 1st place!