Chrysler (Plymouth - Dodge) 2.2 Liter and 2.5 Liter Turbo Engines
The high power, torque, and reliability of the 2.2 turbos sets them apart from many competing engines; the Turbo III could push out 224 horsepower back in 1990, which was exceptional considering that the 2.2 was not engineered with this in mind.
All Chrysler turbocharged engines had multiple-port fuel injection in the US, making them, for some time, the only Chrysler engines to hold that honor.
The company ran through four basic designs:
Two other setups, even less well-known and rarer, were used in the Cosworth-head M4S and in the TC by Maserati.
The first production Chrysler turbocharged engine was a 2.2 liter four-cylinder, launched in 1984, and generation 142 hp at 5,600 rpm and 160 lb-ft of torque at 3,200 rpm - around 30 hp and 30 lb-ft more than the best power made by any other 2.2, and competing with the bigger 3-liter Mitsubishi V6 in power - while turning in superior fuel economy.
To make the engine, Chrysler dropped the compression ratio to 8.5:1 by using deep-dished, strutless, lightweight pistons. For durability, they strengthened the valves and springs, and used better-sealing rings, a special cam, select-fit bearings, and special exhaust manifold; a diecast aluminum cylinder head cover was added, mainly for looks. One key change was switching from a single throttle body injectors to four individual fuel injectors.
Initially, Chrysler used a Garrett Research T-3 turbocharger, with an integral wastegate and maximum boost of 7.2 psi; the wastegate was controlled mechanically, using the difference between the compressor outlet pressure and the throttle body vacuum. When the outlet pressure got too high, the wastegate moved so exhaust gases went directly through the exhaust rather than into the turbine.
The compressor was aluminum, and driven by a turbine wheel in an iron housing with liquid-cooled bearings. The shaft bearing on the exhaust housing side was water-cooled, to reduce hot shutdown bearing failures. Turbocharger bearings were pressure lubricated with oil. A detonation sensor allowed people to use regular gas, with lower performance. The electronics were engineered and built by Chrysler.
Some words from the engine's creators
The 2.2 was never designed for a turbo, according to engineer Pete Hagenbuch; but its durability must have made engineers happy when they chose to force the air in. Pete wrote:
Marc Rozman, engine testing technician, wrote:
Just a year after the company came out with its first turbocharged engine, it gave the computer control over the turbocharger, dropping the mechanical control. Calibrated pressure limits were programmed in; the system turned the wastegate on via the wastegate actuator solenoid. Higher boost pressures compressed a spring connected to an actuator rod, opening the wastegate to bypass the turbocharger.
For year-by-year changes, see our 2.2 / 2.5 Engine Chronology.
1986 also saw a new "fast burn" head design. dyno tester Ed Poplawski wrote, "I worked on this a little bit. We ran Fast Burn heads on the 2.5L and the big advantage was that with the Fast Burn head, wide open throttle spark timing was lower than with the standard head, so you didn't have to worry about spark knock too much and you didn't need premium fuel. That made a big difference for the turbocharged engine."
In 1988, Chrysler described the system:
For the 1990 model year, Chrysler added balance shafts to its turbo engines; they had previously only been used on the 2.5. With the release of the Turbo III in 1991 - one year after the Turbo IV - Chrysler also improved on the 2.5 Turbo I, adding torque through more low-speed boost, and changes to fuel and timing control. The Turbo IV did not make it to 1992; the 2.5 turbo was alone. See the full story on our 2.2 Chronology page.
Diving deeper into the five major turbocharged engines
Turbo I
Lotus' Michael Royce wrote:
2.2 and 2.5 liter engines are all noninterference designs, so they generally are not damaged when the timing belt breaks. Turbo III owners often know this from experience.
There were several different engine blocks, but all had siamesed cylinder bores, a short crankcase skirt, and partial open deck. The block was designed to be milled for lighter weight; it was cast iron rather than aluminum due to the state of technology at the time, and weighs around 90 pounds. The oil pump was mounted internally. Pistons (which vary by engine and year) were aluminum with steel struts, and rings were iron.
Stefan Mullikin noted:
The post-1984 engines had controlled the turbocharger, via the wastegate (except with the Turbo IV), allowing overboost for up to ten seconds; it tried to keep a balance between engine responsiveness and engine life.
The turbocharger itself was cooled partly by the fresh oil circulated through its bearings, partly through a water jacket around the bearings and turbocharger itself, and partly through the air flowing through the engine compartment.
Crankshafts were cast on the Turbo I, and forged on the Turbo II, III, and IV, due to their higher power.
Starting in 1989, all Chrysler four-cylinders, including those in the Dakota and Chrysler TC by Maserati, used the same engine block. The 2.5 swapped its old lengthened deck for a shortened piston.
Key 2.2 - 2.5 turbocharged engine links
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The high power, torque, and reliability of the 2.2 turbos sets them apart from many competing engines; the Turbo III could push out 224 horsepower back in 1990, which was exceptional considering that the 2.2 was not engineered with this in mind.
All Chrysler turbocharged engines had multiple-port fuel injection in the US, making them, for some time, the only Chrysler engines to hold that honor.
The company ran through four basic designs:
- Turbo I - the original, with multiple port injection, producing at least 142 hp
- Turbo II - a more powerful version using a charge air cooler (usually but incorrectly called an intercooler), producing around 174 hp (starting in 1988, these had black manifolds).
- Turbo III - the rare semi-experimental engine with dual overhead cams, four valves per cylinder, and returnless fuel injection, producing an absurd 224 horsepower
- Turbo IV - a pioneering variable nozzle design developed with Garret, to reduce turbo lag (these had black manifolds).
Two other setups, even less well-known and rarer, were used in the Cosworth-head M4S and in the TC by Maserati.
The first production Chrysler turbocharged engine was a 2.2 liter four-cylinder, launched in 1984, and generation 142 hp at 5,600 rpm and 160 lb-ft of torque at 3,200 rpm - around 30 hp and 30 lb-ft more than the best power made by any other 2.2, and competing with the bigger 3-liter Mitsubishi V6 in power - while turning in superior fuel economy.
To make the engine, Chrysler dropped the compression ratio to 8.5:1 by using deep-dished, strutless, lightweight pistons. For durability, they strengthened the valves and springs, and used better-sealing rings, a special cam, select-fit bearings, and special exhaust manifold; a diecast aluminum cylinder head cover was added, mainly for looks. One key change was switching from a single throttle body injectors to four individual fuel injectors.
Initially, Chrysler used a Garrett Research T-3 turbocharger, with an integral wastegate and maximum boost of 7.2 psi; the wastegate was controlled mechanically, using the difference between the compressor outlet pressure and the throttle body vacuum. When the outlet pressure got too high, the wastegate moved so exhaust gases went directly through the exhaust rather than into the turbine.
The compressor was aluminum, and driven by a turbine wheel in an iron housing with liquid-cooled bearings. The shaft bearing on the exhaust housing side was water-cooled, to reduce hot shutdown bearing failures. Turbocharger bearings were pressure lubricated with oil. A detonation sensor allowed people to use regular gas, with lower performance. The electronics were engineered and built by Chrysler.
Some words from the engine's creators
The 2.2 was never designed for a turbo, according to engineer Pete Hagenbuch; but its durability must have made engineers happy when they chose to force the air in. Pete wrote:
Dick Winkles added (2017), "As with any engine program at Chrysler, no one person can claim or deserves all the credit for any given program. I tell people this all the time when they say I did everything on the Viper engine and call me 'The Father of the V-10.' I was simply one of many on a team that pulled it together."
Marc Rozman, engine testing technician, wrote:
Changes
Just a year after the company came out with its first turbocharged engine, it gave the computer control over the turbocharger, dropping the mechanical control. Calibrated pressure limits were programmed in; the system turned the wastegate on via the wastegate actuator solenoid. Higher boost pressures compressed a spring connected to an actuator rod, opening the wastegate to bypass the turbocharger.
For year-by-year changes, see our 2.2 / 2.5 Engine Chronology.
1986 also saw a new "fast burn" head design. dyno tester Ed Poplawski wrote, "I worked on this a little bit. We ran Fast Burn heads on the 2.5L and the big advantage was that with the Fast Burn head, wide open throttle spark timing was lower than with the standard head, so you didn't have to worry about spark knock too much and you didn't need premium fuel. That made a big difference for the turbocharged engine."
In 1988, Chrysler described the system:
For the 1990 model year, Chrysler added balance shafts to its turbo engines; they had previously only been used on the 2.5. With the release of the Turbo III in 1991 - one year after the Turbo IV - Chrysler also improved on the 2.5 Turbo I, adding torque through more low-speed boost, and changes to fuel and timing control. The Turbo IV did not make it to 1992; the 2.5 turbo was alone. See the full story on our 2.2 Chronology page.
Diving deeper into the five major turbocharged engines
Camshaft | 2.5 T | 2.5 TBI | 2.2 T III | 2.2 T I (1987) | 2.2 T I (1989) |
---|---|---|---|---|---|
Intake duration | 228 | 236 | 228 | 240 | 228 |
Exhaust duration | 228 | 232 | 228 | 240 | 228 |
Overlap | 0 | 12 | 0 | 20 | 0 |
Turbo II
Turbo III
Turbo IV
Lotus Engineering and "what might have been"
Lotus' Michael Royce wrote:
Technical
2.2 and 2.5 liter engines are all noninterference designs, so they generally are not damaged when the timing belt breaks. Turbo III owners often know this from experience.
Stefan Mullikin noted:
The turbocharger itself was cooled partly by the fresh oil circulated through its bearings, partly through a water jacket around the bearings and turbocharger itself, and partly through the air flowing through the engine compartment.
Crankshafts were cast on the Turbo I, and forged on the Turbo II, III, and IV, due to their higher power.
Starting in 1989, all Chrysler four-cylinders, including those in the Dakota and Chrysler TC by Maserati, used the same engine block. The 2.5 swapped its old lengthened deck for a shortened piston.
Key 2.2 - 2.5 turbocharged engine links
- Mopar 2.5 / 2.2 Turbo Engines Performance and Common Repairs
- Interview with engine designer Pete Hagenbuch , which covers the 2.2 turbos and other topics.
- Interview with engine designer Willem Weertman, lead engine designer
- Tester Marc Rozman
- Turbo bleeds (to increase boost)
- Rebuilding and enhancing a 2.2 turbo engine
- Turbo boost spiking and boost creep
- Sensors and computer fault codes: what they all do, what they all mean
- Interview with a Garrett turbocharger engineer (at acarplace.com)
- http://www.thedodgegarage.com/turbo_intercooling.html which discusses charge air cooling.
Home •
Engines •
Reviews •
Chrysler 1904-2018 •
Upcoming •
Trucks •
Cars
Spread the word via <!--Tweet or--> Facebook!
We make no guarantees regarding validity or accuracy of information, predictions, or advice - .
Copyright © VerticalScope Inc. All rights reserved. Dodge, Jeep, Chrysler, Ram, and Mopar are trademarks of Fiat Chrysler Automobiles.