Eclipse, Galant, Stratus 3.0L V6 Limitations

Interested in pushing the stock 3.0L engine to it’s limits? Use this as a guide to know what you can expect.

How much power can a V6 SOHC 6G72 mechanically handle is a question that we receive quite a bit. If you own a 3.0L SOHC V6 based vehicle such as the Eclipse, Galant, Stratus or are looking to swap a 3.0L into your vehicle then coming to Tearstone Performance to help scoot your beast a long down the road or track quicker is the right step!

The 6G72 SOHC 3.0L engine is a very reliable engine in naturally aspirated form. Assuming the engine was not neglected on the proper maintenance intervals, you should not be surprised that the 6G72 SOHC will exceed 250K miles. I have a lot of customers that are concerned that once they hit 60k-70k that they’ve hit a “high-mileage” threshold and are wondering if a rebuild is in order. As far as I’m concerned 60-70k on these engines is barely breaking it in. I’ve taken 120k+ mile engines apart and the bearings nearly look brand new still.

The 5speed 6G72 puts down around 180whp (wheel horse power) on a dyno in naturally aspirated form give or take 5whp depending on emissions setup and higher engine compression/plenum design found in the 2003-2005 GTS models.  The Sporttronic or automatic vehicle puts down around 160whp in stock form, give or take based on aforementioned stock configurations.

Basic bolt ons with no ECU flash will bring you up approximately another 10-12whp. The ECU Flash alone even on stock cars has been estimated to add another 15whp. Even then the stock engine will be quite comfortable with that level of horsepower assuming it’s tuned on to a proper A/F ratio. I say that because even on a perfectly stock car if you tune the car improperly you can cause damage to the engine anyways.

6g72dmg.jpgWhere we start to push the limits of the stock engine is with forced induction. One constant we’ve found, even with the 6G74 engines is that the pistons are designed for economy and use a very soft aluminum alloy. With the right amount of heat, this will inevitably begin to pull off chips of the ring land at about 300whp. Turbo sizing plays an important roll in how much heat is processed efficiently through th engine so potentially you are risking tearing up your pistons at a lower boost level / horsepower. Generally we’ve found that a T3/T04e 50 trim is good for about 6psi, and T4 is good for 8psi to keep the engine somewhat reliable.

Nitrous has found to be safer in this realm as long as you are using a wet intake kit. Many owners have used 75 shot kits and have gone through quite a few bottles with no dismay. Then of course I have one engine that is heavily damaged from a direct 75 direct port setup.

If you have intentions of adding a turbo, supercharger or extensive nitrous use on your engine, you definitely want to upgrade to forged pistons at a minimum. The rest of the engine in terms of reliability is built really well except the pistons have always been a problem in terms of adding lots of power to the engine.

At this point, not many vehicles have made it past the 300whp mark. The few that have made it to the 400whp neighborhood still managed to have a reliable setup but has issues with the heads not flowing anymore air efficiently. We guesstimate the stock rods are good for at least 500whp based on the success of the 3000GT platforms. We’ve never heard of anyone having a bent rod unless they sucked up water or hydro-locked their engine. For the few people that have gotten to the 400whp mark, they did it with stock cams so we can only conclude that the heads stop flowing air around that mark.

In terms of ignition limits, many owners that begin pushing 10-12psi begin having issues with the spark blowing out using the stock distributor. It’s best at this time to supplement your existing distributor or convert to coil packs. I would recommend anyone do that in excess of 300whp.

This should give you a road map or some sense of what you are getting into in terms of making power with these engines and vehicles.

21 thoughts on “Eclipse, Galant, Stratus 3.0L V6 Limitations”

  1. Hey i have a 2002 eclipse gt i got a turbo kit off the vr4 v6 3.0 at the junk i was wondering if it would fit and if i have to do any mods to my engine the turbo is stock i beleive td04 turbo

  2. Nice setup! I am looking for everything needed to build the engine to handle boost more efficiently without destroying my motor. Where can I find the pistons and whatever else needed? Thankyou!

  3. I would say I’m a Pro with building my own 6G72 Single Turbo Motor, built everything myself, Did EVERYTHING, Swapped to 5 speed tranny, Quaife Limited Slip, Custom Billet Stage 2 Cams, Custom Valve Springs, Did my own Port n Polish Job, Bored 40 over, CP Racing Pistons, Pauter Rods, Had Bearings Tri-Armor Coated, ARP head and Main Studs, Brass Valve Guides, 1mm larger Intake and Exhaust Valves, High Volume Oil Pump, Custom Fluidyne Oil Cooler, Custom Made Oil Catch Can I Made, Micro Tec GT Standalone ECU with Coil Pack conversion wired myself,Polyurethane Engine Mounts, Short Shifter, Clutchmasters 850 Twin Disc Street/Strip Clutch, Custom 10k Chameleon Paint Job(Blue/Purple/Copper), full custom Turbo Exhaust with Nascar Mandrel Bent Flat Exhaust, Recaro Seats, Full Component Sound System, Skyline APEX-GT Intercooler, Ceramic Coated full Exhaust & Turbo Exhaust and Intake Manifold, DEI Titanium Carbon Fiber Looking Exhaust Wrap,M45-Laser Jammer, VIS Carbon Fiber Hood and Trunk, Apex EGT & Boost Gauge, Compustar Alarm System, OBX Vacuum Block with Stainless Vacuum lines, 4-Custom Welded 10an Ports welded on Valve Covers connected to Catch Can, Custom Billet Twin In-Tank Fuel Pump System, Aeormotive 100 Micron Fuel Filter, RC750cc Peak n Hold injectors, Custom Made Billet Fuel Rail, AEM Fuel Pressure Regulator, All Aeroquip S.S. Lines for Fuel and Vacuum Lines, Driveshaft Shop Stage 5 Front Axles with New Hubs, ARP Wheel Studs, Garrett GT40R Turbo, Momo Steering Wheel, Sparco Manual foot pedals, AEM Boost Sensor, Innovative Wideband O2, Full 3″ S.S. Exhaust, Eibach Rear Sway Bar, German Porsche OEM Xenon Headlights, Tein S.S. Coilovers with Tein EDFC, Custom ordered 19″ Hyper 5ZR 5zigen rims wrapped with 235 Nitto 555ZR tires, Brembo Big Brakes with Custom Powder Coated Copper and Titanium Shims for pads all around,I did All the Work installation, wiring myself besides Boring the motor out 40 over…

    1. Hi,

      I have an 8g v6 Galant that i’m trying to swap to a 5 speed from an 02 Eclipse with the same motor.

      Will you please provide me with the list of what is needed or at least with things to watch out for.

      The more information you will provide, the much appreciative I will be of those.

      Thanks once again.

      Arfa

  4. Hi how much power can the block handle plan on a awd conversion also if im doing my numbers right i can get up to 1200hp or more. Can the 6g/72 block handle that

  5. I have a mitsubishi mirage whit 3.0 v6 come fron mitsubishi eclipse 03 i have comp from montero 03 the cars start really good run really good bot i have 225 hp i want more mi question if what turbo kid is good for that engine

  6. i have a 03 GTS with head motor, would the 6G72 from a 01 galant work on it not worried about the 10:1 just worried about smog in CA.

  7. The vr4 and the eclipse is the same engine 6g72..i got GE pistons and broward croward rods. They have it listed for the vr4 3000 gt but it is the same. The cams i got them from rpw australia. I got 272/272. They are nice. Professionally made. They come with no specs but on their website you can print out the instructions to get the specs with simple tools. You must find someone who can do this. They also have an intake for the eclipse.

  8. Hey I want to know if the engines are interchangeable between different models. ie 3000gt 6G72 bolt in to Galant with no issues. I have a 2001 Galant that I want to bring back to life and would like to have more options for cost and availability reasons. It has a 6G72 in it and I am hoping I have multiple donors available. Thanks for your time!

    1. 3000GT motor won’t fit. You’ll need to stick with the N/A (non DOHC) family of engines. 6G72, 6G74 and 6G75 will all fit ok, some modification is needed.

  9. I’ve heard a few people say the 6g72 that came in the Eclipses is quite different than the 6g72’s that came in the Chrysler, Dodge and Plymouth minivans, sedans and coupes of the same era. And because of this they say swapping for example a ’91 Stealth SOHC into a same model year 6g72 Dodge Caravan, is rather difficult and that’s why you don’t see it done.

    Chrysler had to have built millions of minivans (and sedans and coupes) over the several year run that had the “Chrysler version” of the 6g72 was available in them. Due to how many were built over the years, it seems somewhat surprising we don’t see more of these modded or built Moparized 6g72’s.

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