Turbocharging the Mitsubishi / Chrysler 3.0 Liter V-6 Engine
The Mitsubishi/Chrysler 3.0L engine has been in many different automobiles and in a few different configurations since around 1987: Chrysler has used a SOHC version in the Acclaim, Caravan, Duster, Lebaron, New Yorker, Shadow, Spirit, Voyager, the Chrysler-Maserati TC, and the base Stealth. Mitsubishi has used a SOHC, DOHC, and a DOHC Twin-Turbo in vehicles such as the Challenger, Diamante, Galant, Montero (24 valve), Pajero, Sigma, Triton, Velada, and the 3000GT/Stealth R/T. Hyundai also used it as the V6 option in their Sonata (Mitsubishi is part owner).
While the DOHC Twin-Turbo 3000GT/Stealth has always received a lot of attention, few were made. The SOHC version was used in hundreds of thousands of cars. Most of the Chrysler cars these are in also had the option of the popular 2.2/2.5L turbo motors. Chrysler has made more turbo cars than anyone, and that takes the attention of many looking for speed.
The V6, though, was generated 141-150 horsepower and 171-183 foot pounds of torque. This was comparable to the Turbo I motor (non-intercooled), and when slightly modified, the V6 it is up at Turbo II (intercooled) number.
When I started looking for performance upgrades for my 3.0L, I was disappointed to see that almost all performance parts were for the 4-cylinder turbo models. Finding info on the V6 is not easy. I believe that because of the high flat torque curve starting at a low RPM and usually light weight of the vehicles, that more places should be making more performance parts for this engine. It has been shown that the 3.0L can put up some impressive numbers being only slightly modified and could be improved quite a bit more.
The 3.0L used in the dyno chart above had the following bolt-ons: Cold air set up with a cylinder K&N filter, 52mm Throttle Body, Underdrive Pulleys, Exhaust, 180 degree thermostat, Mopar 8mm wires, and had the stock coil moved to the front of the air plenum. These mods cost about a total of $350-$400 and assuming a 15% power loss from engine to wheels put its numbers at 180 hp / 210 lb/ft. That is a very good power increase for the price.
Current available mods are:
- Underdrive Pulley System from Forward Motion, Inc.
- Upgrading to the 52 mm Throttle Body from a 3.3L engine or a 1987 Dodge Caravan 3.0L
- 2.25" mandrel-bent exhaust pipe and muffler from Dynamax
- Electronic Ignition System (MSD 6A) from MSD Ignitions
- Better wires and spark plugs.
- Setting timing higher to 14 or 15 degrees (do not do if you are installing the turbo.)
While working on prototypes for what became the Daytona IROC R/T, Chrysler modified the SOHC 3.0L into a turbo engine. There are a few for sale for $3500. These seem to be exactly like the regular SOHC 3.0L except these use an intake like the SOHC Stealth. The 3.0 block is capable of handling great amounts of power; 300+ hp Stealths and 3000GTs use the same block and bottom end.
A turbo presents a need for more fuel which can be covered by the following:
- Mitsubishi VR4 / Dodge Stealth R/T Fuel Injectors
- Holley high-flow fuel pump
- Adjustable fuel pressure regulator from Lambros Race Engineering
The Mitsubishi TD05H 16G is close in size and flow to the T3 Garrett and can be bought new for $600. It supports around 300hp and spools quickly in this application. It comes with an integral wastegate set for 11 psi of boost.
I think it should be set down to 9 psi for a stock 3.0, and at 9 psi it should produce 260 hp / 270 lb-ft intercooled with a decent exhaust. One should also port the intake and exhaust manifolds. My plan is to also port the T-body and intake opening to 56mm (the most that can be - thin walls). I would recommend doing all the aforementioned mods first though before considering the turbo project.
- Mitsubishi TD05H 16G from Texas Rebuild $599 (for 1)
- Intercooler probably from junk Conquest / Starion (I've heard they are very good and probably will be cheap)
- Fuel Injectors: get stock one's for VR-4 / Stealth R/T
- Manifolds Ported: Up to each individual to get done
- Fuel Pump: Holley? Find out which the Turbo Shelby guys use.
- Blow-off Valve: a 1st generation DSM (pre-1995) BOV. $50-$75 from the DSM Parts Trader.
- Port T-body - 56mm opening
- Hoses and Piping
- Air/Fuel Gauge
- Boost Gauge
I think this kit is good price-wise, considering most turbo kits are like $2500-$3000. The most built-up 3.0L I know has ~260hp naturally aspirated (near 400hp on NOS), but that is with $6000 into the engine alone. So power can be obtained. But the turbo will be the most bang for the buck.
I do not guaranty this setup will work or perform as expected. The rest of the car needs to be in good shape.
Some other parts I would like to see made are:
- Adjustable Cam Sprockets
- 4-valve cylinder heads (Chrysler made prototypes - produced an extra 60hp!)
I even thought about that ICON from Superchips. $400, but for an extra $100, you can edit everything from a computer. Just get a little handheld, mount it in the dash, and change timing curves, fuel pressure, etc. on the fly.