hi all
i have a mitsubishi pajero 1989 5 doors with 4D56 turbo intercooler , i was thinking to replace the fan set " the fan and the clutch " with a dual elctice fans set , to get more HP and more power in the desert and soft sand . i relaise that the eng. get to over heat when i push the car in the soft sand and i think it's time to replace the cluch , so the idea to do some changes to get some power too
and ideas
thanks :grouphug:

The electric ones will work better especillly at low revs but you will not gain any hp as the energy to drive these comes from the alternator which comes from the engine.

Jim

In all actuality , well i have dun many dual fan conversions in place of the thermostatic viscous coupled fan clutches on these models all the way frum 1978-2005 models.

As most models , depending on the origin and destination. As for instance Asian markets that were assembled in Japan or Thailand for asian markets and Also most North and South African modelsand north African/Egypt and desert destinations and the UAE (United Arab Emerites) and certain surrounding areas with a "high capacity cooling" main things were beefier radiator and coolant hoses Coolant resivoir containers and bypass containers.

The biggest diffrences were most regular model Pajero and Shogun and i think american Montero , had one electric "a/c condensor" fan mounted on the a/c condensor side , which is visible when looking thru the front grille mainlly to compensate for the design of the thermostatic viscous coupled fan clutch desiganated for these models. The Condensor fan would come on with the A/C on to further cool down the A/C condensor for maximum operation. The thermostatic fan clutch with viscous coupling on these models , its main mode of operation is at idle. this is where the thermostatic viscous coupling mainly comes into effect. At low RPM when it can pick up direct heat frum the radiator on its own. The thermostatic viscous coupling increases drag at 600-1500 rpm and the fan will spin between 45 to 100 percent of the engines rotational spin . When the RPM exceeds the viscous coupling limits at near 2000 RPm , most at 1600 to 1800 RPM they free up not to cause engine drag , and also with incoming air thru the frunt of the vehicle also causing the thermostatic part of the viscous coupling to further release.

Long story short , most Japanese production models as well as Thailand(Thailand til 2004) Pajero/Shogun models for Thailand or desert terrain and areas such as the UAE , african deserts and all similar areas had 2 heavy duty condensor side radiator fans. There was wa sstill a viscous thermostatic fan clutch but it served minimal duty. Which its main operation was 500-1400 RPM . To which the The DUAL electric cooling fans that are located in front of the a/c condensor comes in as needed and cycles semi erratic or same time to keep a constant cool of the engine coolant in high heat , high heat trekking as in deserts or other places where , where 4WD was in use and low engine rpm was in use in tough terraine , which was higher than the operation of either or viscous coupled thermostatic fan clutch range of max operation. Which were in 1800-2500 rpm on most comon treks in top range gear selection , to which the vehicle was working on TQ to get thru the roughs and not enough stream of air would be passing thru the frunt of the vehicle to amply cool off the radiator and the fan clutch was out of mas operating range.

On DOCH and GDI model Pajero and Shogun using dual radiator cooling fans instead of the viscous thermostatic coupled fan clutch , it will free up between 8-15 HP and also improve fuel economy , improved engine cooling and a widen the low to mid range band of TQ , if yu trek and go offroad etc yu will notice a BIG differance

On SOCH engines and SOCH GDI , there is still a noticable gain , especially in low end TQ , especially because SOCH and SOCH GDI petrol Pajero/Shogun use an inhanced intake plenum to aid it in delivering a wide and low band of TQ at lower rpm engine speeds. Fuel Economy will also be up with freeing 6-9/10 HP

On Diesel models , 2.5 non turbo or charge air cooler , better and more stable cooling range . As for HP gain i am uncertain as diesel models mainly rely on TQ.

On 2.5 turbo diesel its about the same as the non turbo.

On 2.5 diesel with turbo and charge air cooler , a gain in 18-24 HP , with higher variation depending on turbocharger and size of charge air cooler . The dual cooling fans offer more sufficient cooling capacity to the radiator and charge air cooler on TD models with a charge air cooler. The cooler the compressed air after leaving the charge air cooler the more HP and broader range of TQ.

On 3.2 DiD its mush as the same for the 2.5 , but with a bigger HP and TQ curve for models with a turbo and charge air cooler

There are many ways to get it done. Sum older Diamante/Magna V6 had a single cooling fan shroud that housed 2 radiator cooling fans which is ideal in most cases because the radiators are near exact in length, the height tho may vary. But that is not important. The most important is filling the widith of the radiator, loosing an inch or twho to height is no issue at all. The coolant flow is top to bottom , so loosing a little on height top to bottom on the shroud assembly will not matter .

Or is yur more in to custom as i am most of the time , it will not be hard to find 2 radiator cooling fans and shrouds that will measure pretty much to wut yu need then in widith and height. The onlee main concern is bracket stays to hold the cooling fans and shrouds right at the radiator and be very stable. Ive usually went to places that sold metal or fabrication shops , teh bar does not to be relativelly thick , but able to span the widith of the radiator so both fans can bolt to it . To which yu will use a similar bar to which yu will need to fabricate it with a sharp 90 degrees bend , one for both top ends. In most cases , i put 3. 1 at each upper end of the bar holding the cooling fan shroud and one directly in the middle . If yu do the bends on all 2 or 3 just right they can be properlly attachedaround the radiator reinforcment bracket or upper radiator support and NOT TO THE RADIATOR directly

The lower brace and mount brackets are pretty similar to the top ones , but it will bolt crossways as in most cases i do , i get a metal thin bar longer than the radiator length , and it will bolt securelly to the framing on the lower area of the radiator support frame (not the radiator)

This lower brace design is easy and also very compatible as it does not cause any space confliction with the lower radiator hose and transmission fluid connecters as the connect to the bottom of the radiator, also it is compliable with models that have external engine oil to cooler lines that run in that same area , and models with an auxillary transmission cooler lines that go under the radiator.

Radiator cooling fan motors i have always choosen , unless said otehrwise by the customer. Were ones similar to the 1995/ or 1996 up to 2004 Mitsubishi Diamante. They are dual operational (high and low speed) and they are very efficient and do not take a large electrical charge to operate , and will be very friendly to yur current charging system.

The cooling fans which are dual mode as the Diamante have 4 wires each , 2 seperate plug ins per fan. One plug in is for low /alt fan speed , as which it is good and its main use if for a/c operation, to which they are on at an low/alt fan speed constantly to offer constant cooling to the a/c condensor and radiator when a/c is in operation.

The high speed connection is merely for radiator/engine coolant cool down at set temps , to which they cycle between temperature ranges.

Wiring isnt as hard as it seems. Like when i get Diamante style dual operation cooling fan motors , i go to a salvage and get the radiator cooling fan wiring as far as i can get. And i usually use 4 heavy duty relays for the cooling fans. One for the high speed and one for the low speed per fan. This is the best way. Ive seen sum guys use just 1 for high speed and 1 for low speed, which both fans would feed off the same relay for high and low. Which is not good , having both fans wired to the same relay , especially for high speed setting and constant a/c on for low speed , depending on how good the relay is it will overheat the relay.

Ralliart and Mitsubishi Thailand LM i kno used to sell an aux cooling temp sensor for add on electric condensor fan. Anywaythe low speed setting for a/c operation is easy.

The underhood fuse block has the correct auxillary assessory power terminals, depending how yu wire it up. But to a most , The relay needs a constant 12v , one of the hot terminals on the relay is going to send power to teh fan, when the relay is gauged. Depending teh relay yu buy it will have an wiring schematics for correctgly wiring it up. Anyway , There will be 3 positive current and one negative current connection on the relay. One will be a 12v that enables the relay , the otehr positive will be the 12v power source , and the other 12v will be the source power leaving the relay going to the electric fan when the relay is enabled .

There are 2 ways to hook the low speed fan relay. 1 way is via the a/c compressor clutch circuit (which is a positive continuity wire )
There will be a 12v constant positive continuity going to the relay (best to route frum underhood junction in underhood fuse panel in the extra maxi slot or adjacent one)
The other large positive current wire leaving the relay will go to the radiator cooling fan to supply power when the relay is engaged. Since yu will be using the positive current frum the a/c compressor clutch circuit , teh ground wire at the relay just needs to be grounded , when the a/c compressor engages it will send positive current to the relay to engage and operate the low speed setting on the fans.

The way ive wired up the low speed setting relay is nearly identical , Except i do not use the compressor clutch engage wire . I use the ground signal frum the a/c drier. This way if the compressor clutch frequantlly engages and disengages as in sum auto modes , or bi temp settings , the ralay and the fans will not kick in and out as the compressor does. It will operate the fans at a constant by the climate control signal to the a/c pressure switch. The relay will have the same 12v constant entering the relay and the 12v input to the fan leaving the relay. This time the 12v source that is used , when getting 12v continuity frum teh a/c compressor clutch circuit , will now go to the aux key on onlee power terminal in the underhood fuse panel . And instead the ground circuit to the relay being body grounded , it will get its ground circuit frum the a/c pressure switch

The core wire setup is the same for the high run / high speed coolant fan setting. There are many places that sell auxillary mountable temp switches that have certain degree contact points. I use these alot , Usually 160-165 heat rangedepending and most i have at 190 degrees . These which i have found very useful can be mounted t the radiator or engine block . These work on a groound signal , so the relay would be wired up just like the second example given for the a/c low speed relay for the fans. The ground signal will come frum the temp switch and send it to the relay when its a certain temp , enabling the relay and fan for high speed operation

There you have it, the most comphrensive fan reply I've ever seen. Thanks for taking the time to post such a detailed explanation KIT. I've certainly learned allot but I would question the hp gain with going electric as this assumes no increased load on alternator for fan operation.

Jim

Load bearing on the alternator is really of no issue at all . The alternator changes charge load all the time during driving and at night . The alternator can easily deal with supplying power for the engines cooling fans. As it will not cause a strain on the charging system no more than the a/c compressor clutch operation.

The additional charging load to the engine is non noticeble and brings up the charge rate 2 percent when cooling fans are in low speed and almost 5 when in high speed . As in the compressor clutch in itself to engage brings up the charge 4 percent itself when it engages , not to mention engine load.