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 (and rightfully so), the numbers of these cars made is very limited. The SOHC version on the other hand is in probably hundreds of thousands of cars worldwide. 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.
But let's look at the numbers and compare: The 3.0L used in Mopars is a 3.0 Liter, 181 cubic inch, Single-Overhead Cam, V6 with Multiport Fuel Injection. The power numbers Chrysler have given are 141-150 horsepower and 171-183 foot pounds of torque. This is comparable to the Turbo I motor (non-intercooled), and when it is slightly modified, it is up at Turbo II (intercooled) number. Most of the cars it is in weigh between 2700 and 3000 lb.. This calculates to an estimated quarter-mile time of middle to low 15s.
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 that easy. Not even Chrysler makes performance parts for the V6! I am still looking to see if Mitsubishi does, but have not found anything. This is a shame. 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.
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The 3.0L used in the Dyno chart 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. But most of us 3.0L owners want more.
The current available mods are:
- K&N cone or replacement filter from K&N Engineering, Inc
- 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. See the Mitsubishi V6 3.0L Turbo page for pictures. 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.
We also have seen that the 3.0L is capable of handling great amounts of power because the 300+ hp Stealths and 3000GTs use the same block and bottom end. Also, the turbo kit could easily be made for our engine. A kit would be comparatively easy, as the throttle body and exhaust manifold are near each other with that area of the engine bay open. Also, an intercooler should not have any clearance problems, as most or our cars had the option of an intercooled turbo 4 cylinder. If kits are made for cars like Probes, then certainly one should be made for our 3.0s.
Of course, 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 turbo that should be used is the Mitsubishi TD05H 16G turbo. It is very close in size and flow to the T3 Garrett and can be bought new for $599, less if bought in volume. It will support around 300hp and spool very 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 descent 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 (any ideas?)
- Boost Gauge (Hopefully we will be able to find stock dashes out of turbo cars.)
It's a lot of money, (probably around $1000), but a lot of power also. Also if later you rebuilt, you could also increase boost for more power. 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.
If you would like to join in getting these parts as a group for a discount, please contact me. Doing this does not lock you in to paying any money out or anything like that. When enough people have contacted me, I will call the places in question and ask for a discounted rate. If they agree, I will e-mail all the people listed for that item and ask if you want and/or can buy at that time. We can probably set it up so that everyone sends their own money to the companies and has it sent directly to their address, but this way they know we were together and can still get the discount. I really don't want the responsibility or problems associated with people sending me money and then me sending it to the supplier. As with most of you, I can't just fork out $1000 right now for a luxury item for my car, so I think one piece at a time will be good (probably cheapest to finally the turbo). Remember some things will have to be done by the individual (getting manifold's ported, installing). My regular job is designing tooling using AutoCAD, so I am in the process of making drawing and making them pictures to show how to install it, etc. If you have AutoCAD at home, I can send the actual dwg file.
Of course, as in everything, I do not guaranty this setup will work or perform as expected. Along with more power, the rest of the car needs to be in good shape also. I am only trying to make it easier for us 3.0 owners to be able to be proud of their cars, and to make more power out of their engines. As with all of you, I hope this works as expected. If so, a lot of supposed fast cars will be left in the dust.
Based on estimated by myself and others, this should give a GOOD running 3.0L and extra real 100hp at the engine. Please make sure your engine is in running well first.
If anyone knows of any other suppliers or manufacturers with better prices or better quality, please feel free to e-mail me.
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 running Windows CE, mount it in the dash, and change timing curves, fuel pressure, etc. on the fly. Any ideas on this would be appreciated.
