MN Triton 4m41 3.2 Performance Conversion Build

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MN Triton 4m41 3.2 Performance Conversion Build

Postby Autospecialist on Sun May 26, 2024 8:13 am

Morning all..

So thought I'd start a new thread so those who are interested can follow along...
I've been tasked with building a 250rwhp 4m41 3.2l engine to go into an MN triton (yes bin the 2.5l).

I have a workshop and am a triton specialist. Customers budget is $30k. This is not my personal vehicle.

Current plans...
Source a pajero 4th gen 4m41 long motor
Purchase a Garrett gtx2863r with 0.64 compressor housing
Build a custom mandrel bent exhaust manifold
3inch mild steel exhaust with custom downpipe
Acl race bearings throughout
Arp head studs
Port and polished everything.
Large front mount intercooler (vehicle has existing)
Modified injection pump - new
+30 injectors - new
Npc super heavy duty clutch kit with flywheel
Redarc boost egt oil pressure and temp gauges
Alphatec 3 map select piggyback ecu (may need to be standalone)

I think that's about it for now.

I have done a 4th gen pajero swap into an ML previously with great results. So I'm aware of most of the items that need modification. The only unknown is the ecm hurdles however I have experience in standalone ecus and building wiring harnesses.

Should be an interesting build. I'll keep this thread updated whenever I can.

Expected time frame for completion.. 2-3 months
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Joined: Sun Jan 09, 2022 3:38 am


Re: MN Triton 4m41 3.2 Performance Conversion Build

Postby NowForThe5th on Sun May 26, 2024 2:44 pm

Great idea!

Do bin the 4D56T. 250rwhp is only 186kW. Not a lot more than the standard 147kW (although I do understand one's flywheel and the other is at rear wheels).

I have an NW Pajero which currently produces around 235kW and others have done Triton 4M41 engines up to 300hp. So the basics are all there - just need to extract what they're capable of.

A few comments on your plan:

The Gen4 motor comes with and works best with a variable vane turbocharger. No need to change the exhaust side, just the intake.

Custom manifold. Gains will be fairly small for the effort and money invested.

3" exhaust. Waste of time and will lead to errors and limp modes. 2.75" works much better and most Pajero owners don't even bother changing the standard exhaust.

Bearings, studs, port & polish. The last will probably have the most effect. The 4M41 is one strong little engine and can produce with the factory internals.

Intercooler. Be careful. Larger is not always better, although up to about 30% will improve cooling and therefore performance. A smaller quality intercooler can do much more than a larger unit of lower quality, and therefore performance.

The injection pump is not the problem. At the common rail pressures that I run the weak spot is the common rail itself. Blown two so far, straight out the side. Castings less than perfect? Don't know. You'll need to brick the relief valve, of course.

If work is so terrific, why do they have to pay us to do it?
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Location: Holt, ACT

Re: MN Triton 4m41 3.2 Performance Conversion Build

Postby Autospecialist on Sun Jun 02, 2024 6:33 am

Appreciate your input.

I won't talk too badly about the 4d56 as I'm currently building a compound setup for my own personal mn triton. Currently had 220rwhp but is way too laggy. Let's not get off topic however.

I'm concerned the stock vgt won't get the numbers she wants. Remember the target is 250rwhp and atleast 600nm.

Custom exhaust manifold is important to the customer more so for aesthetics than for performance gains. The 3inch gives far better heat distribution and as for ecm errors that's not a problem, I've recently started winols training and have abit of experience with ecu recoding/remapping. Still not sure how I plan to run that side of it. As the 4m41 has a different cam pickup it may need a standalone or possibly use a 4m41 ecm. I know a 3 map select option is preferable (alphatec or similar).

There is a great thread on the pajero forums that I have stolen alot of r&d from. He spent 2 years and well over $30k trying to achieve a similar goal.

If anyone has any contacts for a modified intake manifold that would be handy.

In regards to the engine I've managed to source one through my contacts that has only been overheated so that's a great starting point. I shall pick that up in the coming week and strip it down.

Chat soon.
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Joined: Sun Jan 09, 2022 3:38 am

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