Top Mount Intercooler Woes 

Top mount coolers are more efficient than front mount coolers due to thermal loss, the shorter the charge air pipe the better. with front mount you have long lengths of ducting/piping running from the front of the engine bay and by the time the cooled charge air reaches inlet manifold those 0.9-1.2mm wall pipes have heated up from normal under bonnet engine heat.

Found a water to air intercooler that fits that bracket and a heat exchanger that fits behind the grill without removing anything and I have factory steel bullbar and winch in it, the going a bonnet vent a r34 gtr ztune style. So hot air can get dragged out the top and pull more air through the front of the car.

Your right about air flow over bonnet had gum leaves siting on top driving along and they didnt blow off doing 110 on the freeway no air flow at all !

mount it on the roof rack with a fan like a trains cooling system

Bonnet scoops are small except for the 1st gen dmaxs haha

Not true. There are areas on a car with high and with low pressure. a high pressure zone is in front of the grill. This is why OEM grills are a kind of recessed to funnel the air and force it through the radiator set. Above the bonnet is a lot flow - a really high pressure zone is the windshield of course. I drive a bmw z3 in germany, so a lot faster probably than most. After the rain you can see that the rain follows exactly the curves of my bonnet. If an idiot places lights and or a spoiler on the front of the bonnet and expect it to work factory. Than this person need an advice to do better.

Just mount a thermo fan on top of the intercooler and remove some of the rubber from under the bonnet.

Interwarmer!

That light bar is in an illegal position. They cannot be mounted on top of bullbars. ADR 13

If you don't have room on the bottom of the cooler can you put on the top of the cooler coz I have a similar problem

So what you think about the prado 120 that draws the air from the front grill through the bonnet then over the intercooler. fan would help at lower speeds while 4wding etc. Would you still put a fan on.

I’m in the process of researching upgrading my intercooler. I have a gen 4 3.2DiD Pajero, the factory location of the intercooler is actually the lowest point on the car. I was considering a top mount with fans, as a opposed to a FMIC as I’m concerned about restricting the flow to radiator and aircon. Have you come across a Gen 4 intercooler mods?

Would you recommend a front mount intercooler on a td42ti gu patrol ? would it cause restrictions on the radiator ?

Water methanol injection kit, problem solved

What fans do you use?

Boy oh boy you have no idea what you are talking about! The scope is quite large, at low running speeds the thermal fan(s) do the cooling and at speeds over 40kph the air coming through the "scoop" does. How a scoop works is from the air being pushed into it from the vehicle moving through the air. So if the vehicle is doing 100kph (in theory) the going into scoop and the intercooler is doing approximately -100kph. (There is a lot of variables with this!) As the air has nowhere to go (in the scoop) but down and is under pressure through the intercooler. It's is also a compromise as the bigger the scoop the more wind resistance (at speed) the vehicle gets. On a sidenote, top mount intercoolers are not very efficient as the get heat soak from the engine but place there for protection from frontal protrusions damaging them (like WRX's). SO scoops are for high speeds and thermal fans are for low speed. (The same applies to engine water radiators)