You'll need to consider doing a full T2 upgrade from the T1 log motor as well to hit the golden 300HP mark. And the A555 is a must have at that power level for sure. Been there done that. You will also need a custom cal w/either engine.
The 2.2 or 2.5 will serve you equally well, a 2.5 has better low end torque for a heavier car like the G body Daytona, but a 2.2 is a better rev'r so if RPM is your drug of choice go with the 2.2. Your car came w/a 2.2 from the factory, it's a prooven combo when combined with the proper final drive tranny.
This article deals with converting pre-1988 Chrysler turbo 1 cars to turbo 2 status. This article also specifically deals with converting a 1985 turbo 1 L-body (ie Shelby Charger, GLHT) but will apply to other bodies and years and known differences will be noted. Also I assume no resposiblity as to the validity of this information, and assume no responsibility for any damage or harm that may come to you by using this information. And as always when working on an automobile certain safety procedures must be followed. This article is written as my experince with converting my 1985 Shebly Charger with the knowledge mostly gained from those generous souls on the SDML (Shelby Dodge Mailing List - Shelby Dodge Mailing List (SDML)
The most popular reason for doing this conversion is the addition of an intercooler. An intercooler could be added to a 1988 and later turbo 1 quite easily becuase of the revision of the intake design lends itself much better to intercooler tubing. If you notice the outlet of your early turbo 1, the turbo and the inlet of the intake they are pointing directly at each other with no room to run tubing in between. It is possible to cut off the inlet to the intake and re-weld it pointing forward in order to add the intercooler tubing but the later style intake used in the turbo 2 conversion flows much better and more evenly between ports. The reason people like to add intercoolers to their turbo cars is that it allows higher levels of boost pressure to be safely run in the engine and thus more power put out because the more air molecules in the combustion chamber (ie higher pressure and more dense from cooling) the more expansion occurs. The intercoooler allows this because the boost pressure safely run is limited by detonation within the engine or high combustion temperatures, both of which will ultimately ruin pistons as well as other internal components. The intercooler prevents this by cooling the compressed air coming out of the turbo before it goes into the head of the engine.
While it may seem that one could just add the new intake and run tubing to the intercooler, you will find several small porblems that add up to warrant doing the complete conversion.
1. The new intake is from a blow-through type system where the throttle body is after the turbo instead of before like you may have now (suck-through system).
2. The new intake with its longer runners, hits the early turbo one exhaust manifold (solved later in article).
3. Since the old intake did not flow evenly amoung cylinders some injectors are fired richer than others by the computer to compensate.
4. The electronics changed in 1986 to use a new distributor ( this only applies to 1984 or 1985 turbo cars).
5. The wiring is slightly different between the new intake setup and the older one.
1. Along with new intake you need the new style throttle body
2. Get the later style exhaust manifold, or use your own and grind down the section where the intake and exhaust hit. Note this is the only difference between the early TI and the later TI/TII manifolds is the later is notched appropriately).
3. Use a TII computer
4. If you have a 1985 distributor, get the new shorter, wider, 1986 distibutor and internal elctronics (hall-effect pick up).
5. Get the new end connectors for the TPS (throttle position sensor) and AIS (automatic idle speed) motor
Intake: 1988 or later turbo intake off any model Chrysler car
This can be a one piece or two piece intake (off Shelby TII or Daytona TII cars). The two piece intake is much rarer so I would advise using the one piece, while tuned for slightly more low end, is much more abundant.
Injectors: stock TII injectors or mopar performance 804 injectors
While you could use your stock injectors keep in mind that the computer you will be using is calibratred for the TII injectors that flow more and thus you would have to keep an eye on your air to fuel ratio (oxygen sensor guage) to make sure that you don't run lean at higher boost. 804's may run richer than the sotck injectors allowing more boost but that is up in the air some respected individuals have said that Chrysler changed the flow of the injector and is now the same as stock TII injectors.
Fuel Rail: You need the fuel rail and pressure regulator that goes with the intake you got
Distributor: If you have a 1985 car get a 1986 turbo distributor
The turbo elctronics changed in 1986 so if you are intercooling a 1985 turbo I get a 1986 turbo distributor and the internal pick up. L-body turbo 2 cars, 1986 and 1987, both use 1986 electronics. If you have something like a Daytona I belive that the electronics may have been changed in the distributor again in 1987 so I would suggest a 1987 distributor.
Throttle Body: 1988 and on turbo blow through intake or 3.0 - 3.3 V6 multi-point injection throttle body
You can use any blow through throttle body. They are of 46mm diameter. You will also need the AIS and if possible the TPS that goes with the throttle body. The earlier TPS is the same electronically but if you wish to use the later wiring connector the new TPS is needed. The new AIS is a four wire system instead of two and the wiring will be addressed later. You can also use the throttle body off a multipoint injection Chrysler 3.0 or 3.3 V6 which is of 52mm diamater. The TB can be found more easily on early 3.0's (1989?) and all 3.3's I think. This is the TB used in the Super 60 system. It will yeild more power at high rpm and high boost levels but may reduce your fuel efficiency because of lower port velocity. The intake throat must be opened up a bit to accomodate the larger TB butterfly. This will be addressed more later.
Exhaust: 1988 and on Turbo I/II exhuast manifold, or grind your existing one.
If possible pick up the later style exhaust manifold, this will make your job easier. If you can't find the later style or don't want to spend the money on it, it is possible to modify your existing manifold. The only real difference between the two is that the later has a notch in it to clear the new style intake. You can simply use a bench grinder to notch your exisitng one. More discussion will follow on this later.
Computer: Turbo II computer
Dependent on what body car you are converting your computer options may change. For L-bodies you can use the 86-87 GLHS computer with the least effort. It only requires that you add two wires to the red wiring harness connected to the computer. I will address this specifically later but it is for the new two wires on the four wires AIS. These computers may be hard to come by so I would suggest picking up a GLHS Stage II computer from Mopar, they only run $130 from the place I got it. The other choice is to run the CSX Stage II or stock type computer ( I believe the Daytona may use this computer too). This requires the addidtion of the two wires as above and moving two wires to different cavities on the connector. The advantage of this computer is that it has more on RAM and I believe that it makes faster calculations as well. For other body styles, I believe that the Daytona or CSX Turbo II computer should be used or use the CSX Stage II computer.
Intercooler: Stock Turbo II/III/IV intercooler, aftermarket incooler, or Ford, Isuzu, Dodge Conquest, ect....
If you want to go for that stock look, pick up a stock turbo II/III/IV intercooler and radiator. These may be installed into a turbo I with only minor modifactions to mount the radiator. Or just pick up any stock mopar turbo II/III/IV intercooler, a Spearco or other aftermarket intercooler, or other make like a Conquest or Volvo intercooler and mount it up front in the fascia where it will get the most air flow across it like I am doing. Warning some intercoolers may be better than others. Mopar intercoolers are a good choice but the Conquest intercooler is better if you put bigger hose barbs on the end tanks. If you do mount it up front you will have to make your own tubing. But this is not difficult given 2.25 inch exhaust pipe and radiator hose to make it custom to where ever you decide to mount it. Remember the more air that goes through it, the cooler the air inside gets, and the more power you'll produce.
Wiring Connector: 1988 and on Turbo I/II throttle body connection and O2 wiring connector or get GM wiring connectors at NAPA, Car Quest, or other parts outlets
By far the easiest way to add the wiring connectors for the Turbo II blow though throttle and three wire O2 sensor is to pick up these off a salvage yard car. The Turbo II has a three wire O2 sensor. The new two wires just go to ground and ignition 12 volts. While it is not essential to have the three wire oxygen sensor, it would be beneficial to use it since it has an internal heater and will reach operating temperature quicker giving more consistant readings, better emissions, and better cold fuel efficiency. If you cannot find a salvage car to pull these connectors off, you can buy the assembled harnesses from Turbo Electrics.
Turbo: Turbo II turbo or modify existing turbo
The inlet and outlet of early turbo 1 turbo's points straight up, this does not lend well to intercooling since you will have to make sharp turns to point the tubing towards the front of the car. However the compressor housing may be turned forward, so there is no need to get another turbo. Note on turbochargers: The Garret turbo are larger and will flow more air at high boost while the smaller Mitsubishi turbo has less turbo lag and will spoll quicker. Choose turbo's by your planned top boost pressure.
Airfilter: Turbo II or late Turbo I airbox or Cone style universal filter
If you are going for a stock look, pick up a Turbo II or late Turbo I airbox and tubing. If you want maximum performance then I would go with a open element high flow filter perferably ducted with cool air. This is what I will be doing.
Blow-Off Valve: You can get away without picking up a BOV, but if you want the most life out of your turbo then I would suggest getting one. Stock Chrysler BOV's will hold without leaking until about 15 psi and only cost $15 from the dealer. Early Eclipse and Talon BOV's (90-95) will hold until about 20 psi I believe. They use a metal diaphram so they won't swell and burst under high boost.