The Mitsubishi Pajero Owners Club®

[Philco]

Scattered around the forums are several postings from me about the engine tune-up I had done by Van Aaken, a diesel specialist at Crowthorne, Berkshire http://www.vanaaken.com/europe/dieseloptimisation/optimisation.htm so I thought I would re-post here as a place of reference for anyone else who decides to do the same.

The process is called "optimisation" of the engine, for both the 2.5 and 2.8 diesel engines which have mechanical parts, ie pump and turbo, models upto 1996/7, as opposed to those with an engine management system or electronic pump which can be "chipped" for more performance.

Put simply, you take your Paj or Shogun or Delica to them and for a few hours work they will charge you something like £400 (discount for Camping & Caravan Club members) for the privilege ..........they quoted figures of about 17% improvement for the 2.5 but this is all theory, depending upon how well your engine pump and turbo is set up at the moment.......they use their expertise to "optimise" power and fuel ........the general view has been that if you improve power then fuel consumption will increase ...........best to monitor your consumption before and after...........I can only give you after figures being 19mpg around town and 24 mpg on a run .........given the great variance in members fuel consumptions generally, you can only compare your own figures and not with somebody elses........as well as optimising the pump, they modify the turbo to allow more power (pressure) build-up, by adding a "passive bleed valve" which fools the wastegate actuator to delay opening and they also remove the "pressure relief valve" (overboost valve) and blank it off ........see pic below..........the valve is centre pic and the blanking-off nut to the left is just visible



So........did it improve performance I guess the answer is yes........the Paj is a slug, before and after the tune-up but the torque and top end have improved...........top end was 80-85mph............now 100mph (some members already achieve this without the tune-up).............previously on motorway hills, top speed would drop down to 60mph........now it will hold 80 mph (most of the time).
Whether acceleration has improved is unknown, I suspect any change is marginal...........as I have not driven another 2.5 I can't compare, nor can I compare it with the 2.8 as I havn't driven one of those either........in any case, members Paj's are faster / slower than others as normal so impossible to compare.

Would I recommend it ..........I guess if you have the 2.5 then be content with it, if you want one with more power then get one with a bigger engine.............I took the view, was I prepared to spend £400 on a "tune-up" to find out. ...........in my case the answer was yes.........it would also depend upon how far you would have to travel to their only premises in this country.............you decide

[Google]

[MULLAC]

Hi Phil,

Sounds interesting, they are only just down the road from me, it might well be worth my while calling and having a chat.

You seem to be happy with the results on your paj.

Cheers,

Tom

[Philco]

Be good to see if they have any info to hand when you go.........they are reluctant to tell you exactly what they do, wont let you stay and watch and dont give you any performance read-out figures afterwards......unless they've changed their practice..........if you go, let us know what you find out

[MULLAC]

Philco,

Consider it done

Tom