Increasing air flow

G'day brains trust.

I need to increase air flow through the engine bay.
Save a bonnet scoop ( as I cannot find a d22 one cheap enough)

What other options do I have?

you know the driving light hole blanks on the stock front bar ? if you still have the stock bar bumper you could run some flexable 100mm ducting from these 2 areas for the intake and go up or around the inner front guard into the engine bay. this would supply good air intake.

Sorry mate, gotta bullbar

well you have the idea anyway hey. whats the heat issue ?

No real reason why.
I'm of the mind more the better is all
Cannot hurt

mike1303 said:

G'day brains trust.

I need to increase air flow through the engine bay.
Save a bonnet scoop ( as I cannot find a d22 one cheap enough)

What other options do I have?

Click to expand...

Just do what I did, delete tha bonnet = massive airflow.

i do have a used bonnet scoop off a subaru wrx your welcome to have free . just need to cut a big oval shaped hole in the bonnet and screw it on.

Are you wanting to haul extra air through the aircon condensor+intercooler+radiator or do you want to bypass these and introduce extra air behind the radiator separate to that drawn through by the fans?

Option 1: Increase air flow through the front
Grab hold of a Ford thermo fan (I think it's from a AU falcon like this one). Hook up a relay to the battery (fused of course) with a switch inside and control them as you need. Warning: the fans linked to are very efficient and will lower the coolant temps, perhaps enough to bring the thermostat back on or at least confuse the hell out of the ECU. Note that dropping the coolant temp below 85C will also cause the glow plugs to light again. On a really hot day this will help the engine+aircon but it will cause havoc any other time.

Option 2: bringing in separate air around the radiator.
You wouldn't want to do this to cool the turbocharger - that's watercooled already. Trying to pressurise the engine bay can reduce the effectiveness of the radiator, but directing cool air onto the firewall and the transmission tunnel might be of significant benefit in the cabin because they're two places that the air con just doesn't seem to compensate for. How to do it? The only avenue with a bullbar fitted is either through a bonnet scoop or by installing ducting in where the winch would sit and running that ducting into the engine bay and where you want it. Any ducting below the bullbar line would reduce your approach angle. Be aware that bugs, dirt and large amounts of water will be picked up by this so the piping should not be that thin flexible stuff they use for air conditioning in buildings, not that plastic stuff they use for portable air conditioners. The aluminium tubing used for range hood ducting might be worth trying though and comes in 125mm and 150mm - I've got some 100mm here so that's also available.

If you have a winch ... I don't know where you'll get the air from. Customise the steel bar to put intake ducts where the fog lights go in an ARB bar? What about converting a strip intake (taking advantage of the slot above the winch mount and below the driving light mount) to a 100mm duct?

Not sure what you are trying to achieve, but if its reducing airflow through the rad then the bonnet scoop is the go. Even a reverse scoop (a'la A9X Torana, ect) that opens on to the high pressure area before the windscreen will do the same thing and pump air IN to the bonnet which is the opposite of what you would want. Think about it air goes IN the rad, and it has to come out somewhere. Cars like WRX and D22 have bonnet scoops as a band-aid solution to not being able to run a front mount I/C.
If you are having heat problems for some air flow related reason, ducting or louvres in the bonnet directly behind the rad (this area just happens to be a low pressure zone) will draw much more air through the rad and let hot air out like crazy even when parked, not that you would need it unless you have something out of the ordinary under the bonnet or are driving in extreme heat that no one else is getting.

Heres a diagram of what im talking about. The green areas are good areas to vent hot air out.
you dont want any air going in that isnt going through the rad if you can help it.

Thanks fellas
I'm not trying to fix any problems or solve ant issues.
I've always been partial to a bonnet scoop.
And without straight out saying that. Thought I'd see of there was any other options to help keep temps down before I cut a huge hole in the bonnet.



If I could only find s d22 scoop with out it costing me a fortune


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That looks tough, but does nothing for cooling, actually hinders it.

Something like this will actually help;

or this;

The Nissan GTRs have little NACA ducts that blow cold air on to all the fuel lines and whatnot that run near the turbos - something like that or as Johnny suggested - flexible hose from the front or underneath the vehicle to blow air on any critical spots that are prone to heat.

I'd agree with Rabbid on this one Mike, the scoop on the A9X worked very well and was highly regarded, and that was late 70's. You can get those glue on scoops that some use for the wank factor, but with a hole under it will add some cold air. I've not bothered to check the price but it's just plastic shit so it should be cheap enough.

happy john said:

I'd agree with Rabbid on this one Mike, the scoop on the A9X worked very well and was highly regarded, and that was late 70's. You can get those glue on scoops that some use for the wank factor, but with a hole under it will add some cold air. I've not bothered to check the price but it's just plastic shit so it should be cheap enough.

Click to expand...

Forget the A9X style scoop, they were setup for a V8 Engine with a carburettor not a diesel engine and were only effective on race cars

Arrhh yes Bushman, but deep water crossings despite the fact it's a backward directed scoop would be a better choice to keep the area drier.

The backwards scoop like the A9X actually force positive pressure from the windscreen into the carby.
Mike's best bet is probably get whatever scoop he wants and stick it on without cutting the hole.

i thought the a9x scoops working was to take hot air out of the engine bay.

Nahh Jonney, as Rabbid and Bushballs said it's the downdraft from the windscreen mate.

A massive low pressure are is created at the base of the windscreen - the A9x took avantage of that to FEED air into those carbies. Low pressure moves to HIGH pressure around the intake.

Free HP..

Its high pressure. Thats why it blows air into the carby. Check that diagram previous page. Also, there is an area of low pressure (suction) near the front of the bonnet, which is why you see massive louvres, vents and gaping holes in that spot on race cars and time attack cars to aid cooling. Also helps reduce lift.