4M40 performance modification

[vtin]

My first post here! Searching for some knowledge on modifying the 4M40 for performance. I've searched the forum for a while and can only find some tuning related and mild mod topics (exhausts, intercooling, etc).

Has anyone here tried to build the 4M40 into a performance powerplant? Particularly i'm interested in your experiences with porting the head, intake and exhaust manifolds. Would love to hear any other wisdom as to how the 4M40 reacts to performance mods: bigger turbo, higher boost, increased fuelling, bigger and more efficient intercooling, fee flow exhaust, all working together and what gains can be had from a successful setup.

[Big-Bird]

people have tried adjustments to the wastegate spring.
Bigger intercooler and or turbo.
Different injectors
Fiddled with the air intake via a ram-air effect and all with limited effect.
What really unlocks power is the exhaust system. Let any diesel engine breath better and it frees power easily. i did a modest swap from a 2" to a 2.25" minimal bend pipe and hiflow muffler and it made a big change for my L400


Not much available on stroking the 4M40.....BUT if you do some reading on the 4M41 which the electronic injection variable timed 3.2L found in later model Pajero you might find some true power!

All you need is a complete front clip with tranny and computers from a donor Paj and brother they are available.

The engine has very impressive stats and I would consider it in my L400 if money was no object. The engine has been called a 'freight train puller' by some in europe. Personally getting a 2001 Paj with the 3.2TD would be easier.

[vtin]

I have also heard and seen that the exhaust on the 4m40 is restrictive. Even removing the muffler in my Paj spools the turbo about 200rpm earlier. Apparently the exhaust ports in the the head are rather large but the manifold and turbine housing is very restrictive.

I'm considering doing an exhaust porting job from the manifold downstream. Gasket matching and streamlining the manifold, turbine housing ports, wastegate ports and of course larger diameter downpipe and rest of exhaust piping. If everyone is having good results going with less back pressure in the exhaust pipes then streamlining/opening up the manifold and turbine housing a bit wouldn't hurt.

I found a short thread here where someone says they upgraded their compressor to 15t and intercooler. http://www.delica.ca/forum/has-anyone-d ... 10903.html Any one know more info on this setup?

[vtin]

Just thought I'd post up some photos of people's 4M40s in Thailand. They are all in Mitsubishi Stradas, but the engines are all the same as our JDM Delicas and Pajeros with the manual/mechanical IPs. They're mostly set up for drag racing, but in milder configuration these should yeild good power figures.

The turbos these guys are running are mostly BIG externally wastegated Holset and Garret mounted on custom tubular exhaust manifolds. Big front mount intercoolers, solid intake pipes with custom intake manifolds which are just the stock intake runners welded to a big alu tube. The rub here is to supply enough fuel to make use of this setup they need IPs with bigger plungers. I read some are bored to accept 11mm plungers. I don't know what is in the stock pumps that we have, any one who has rebuilt their pump measured the diameter of the plunger? I have a feeling it's something like 9mm. I have now idea about engine internals, but they probably have some porting in the heads, but i've never seen any connecting rods available for the 4M40 so I imagine everything else is stock.

I believe these 4M40 are producing something like 300HP and 600ft/lb of torque. Which is pretty impressive to say the least. So the 4M40 can certainly be a performance power plant.

In any case there is certainly room to increase fueling on our pumps significantly before they can't manage. These Thai 4M40s are running something like 30psi intake pressure so they need more than three times the fuel that the stock pump is set up to deliver. I'm interested in running about 17/18 psi with a much smaller TD04HL-20t turbo, so the stock pump with some tuning to the delivery should be able to provide enough fuel to have a decent mixture. With the HL turbine housing the turbo should spool at about 2000 RPM and remain streetable.

Anyway, on to the photos: