Turbo II Engine

Chrysler's Turbo II engine debuted in the 1987 Daytona Shelby Z. It was also used in the LeBaron GTC convertible. This engine was not available with an automatic, since Chrysler did not have an automatic capable of reliably handling the power. It is possible to install this engine on any of the K-platform cars, and it is also possible to upgrade any Turbo 1 engine to Turbo II specifications.

• 2.2 liter (135 cid)
• Single overhead cam
• Turbocharged
• Multi-point (port) fuel injection
• 174hp @4800 rpm, 200 lb-ft torque @3200 rpm

The Turbo II specific components over and above Turbo 1 are:

• Forged Crankshaft
• Forged Rods
• Floating wrist pins
• Boost increased to 12 psi
• Higher flow injectors
• Intercooler

The main increase of engine power is due to the increased boost, following this complex and detailed formula:

More boost = More power

The bigger injectors are to cover the extra boost, and the forged internals were to make it more warrantable. In actual fact, the forged crank is overkill, crank breakage is extremely rare in non-forged cranks even when running very high horsepower.

In order to convert a T1 engine to T2 specs, you will need to concentrate on safely increasing the boost. This involves several relatively minor modifications.

1) Garrett turbo is much preferred over the Mitsubishi. The smaller Mitsu turbo spools faster, but does not have the ability to provide sustained pressure at the airflow required.

2) Bigger injectors. The T1 injectors are 28pph, the T2's are 33pph. You MUST provide more fuel to handle higher boost. You can either use an adjustable fuel pressure regulator (AFPR) to handle this change, or use a T2 computer. You can also get +20% and +40% injectors for even more fueling and boosting ability, and use a RRG-AFPR (rising rate of gain adjustable fuel pressure regulator). This increases the amount of fuel at higher boost, which keeps things cooler.

3) Boost control. Using the T2 computer will handle this, or use a Grainger valve to take control away from the computer. Personally, I prefer using the MP T2 calibration with the Grainger, since it delays overboost cutout by several seconds.

4) Older T1's used a suck-through throttle body. The throttle plate controlled the amount of air the turbo could suck in. This has disadvantages, though. First, it's not as easy to intercool. Second, if a piece of debris cuts the intake hose, you get full throttle. Convert older T1's to the newer style Blow-through throttle body.

5) Intercool. You MUST cool the charge somewhere between the turbo and the throttle body in order to run higher boost.

Airflow on the blow-through T2 looks like this:

Most T2 owners will modify some aspect of this airflow. The most common mod is to replace the filter box with a more direct filter, or cut open the filter box, or even just stop running the air through the power module (computer, after 1987). More direct access to cold fresh air is a good thing.

Also, increasing the intercooler size and efficiency will return good gains.

Disclaimer: ALWAYS keep any parts you remove from your car. You may be required to replace them to be "street legal", or worse, you may require them at some NHRA sanctioned events. Never "rip" parts off of your car and simply discard them! You will be surprised at how expensive some of these things are if you go to replace them! This page is intended for information only, I do not recommend that you perform any modification that will increase emissions, wake your neighbors, or otherwise cause your vehicle to not conform to local laws.

The first step in increasing power on ANY engine is to open up the exhaust. A turbocharged engine is no exception. You may have heard the rumor that your turbo engine "needs backpressure", but this is a vicious lie spread by turbo-hating V-8 owners. In actual fact, the greater the difference in pressure between the intake and output of the turbo, the more energy can be transferred to the turbine. In other words, the ideal turbo setup has NO exhaust pipe past the turbocharger.

Of course, local sound ordinances state otherwise, and you really must have some kind of muffler; also, you will live longer if the car's noxious waste gases are ejected behind you. For these reasons, you need to have the largest diameter, most gradually bent, and least restrictive pipe running to the back of the car. Contrary to popular belief, there IS enough room to get a 3" exhaust pipe over the rear wheel well in a Daytona (but not in an Omni!). Remember, a larger diameter pipe can safely be closer to the body, since larger pipes run cooler. If you can find it, get "mandrel bent" tubing... it's less restrictive. A 3" normally bent pipe should flow the same as a 2.5" mandrel bent pipe. Consider removing the catalytic converter, especially if it's original (it may just be dead weight by now, anyway). Replace the cat with a hollow cat or a resonator. Any competent muffler shop in your area will be familiar with the local legal requirements for positioning and muffling, keep it legal.

Consider this: what happens to all the pressure that is generated by the turbocharger when you lift your foot off the gas to shift? The pressure builds up in the intercooler and hoses, which causes the turbocharger to encounter resistance, and actually slow down. Once you're done shifting, and slam the gas pedal again, the turbocharger has to get back up to speed.

To eliminate this, you need a BOV, or blow-off valve. There are many makes and models, from plastic to metal, even some that can hold 100 psi of boost. Consider your budget and requirements, of course, but a BOV is a definite advantage in any turbo car.  Essentially, whenever your intake manifold is in vacuum (when your foot is off the gas), this valve opens and allows pressure to escape, thus keeping the turbo up to speed.

Here is an exploded view of the intake and exhaust manifolds for the 87:

On this site (check the menu to the left) you will find some useful information in both the Maintenance and Modifications links.