Outer Limits 4x4 Board

just wondering if anyone has put a bonnet scoop on a defender bonnet in the raised skinny part? i have my intercooler where the heater box 'used' to be, back passenger corner, and trying to get of the shelf scoop for it.

i've tried autobarn, nissan, repco, surpercheap & a couple of jap car body kit places

is there a bonnet scoop that skinny, apporx. 150mm wide? or do i have to fab one up?

What about one of thos small louvered panels, rather than a scoop?



e.g. like this on the WRX (and heaps of other japanese cars).

I was under the impression that the forward facing scoops are trying to force cool air into an area that is already under high pressure from the air that passes through the radiator, and can make the whole cooling system less efficient. Turn it around and I guess it relieves the pressure and makes it more efficient, but then again, who wants hot air passing through an intercooler.

http://www.spoilershop.com.au/front/

What about a GU scoop , see heaps of L/R110 over here with them on ....$145 from Nissan

here is one on my old Rangie

I believe that it needs to be faced forward to be legal (If that matters to you or not )
Reason being, if any form of hose breaks/bursts, sending oil/water/coolant all over the windscreen affecting vision ect...

There a heap of bonnet scoops & bonnet vents at Sydney Special Vehicles

ssv.com.au

I put one of theirs on my last car, a backward facing scoop in the low pressure area of the bonnet, to help relieve the underbonnet temps.

Why not just stick a fan on the intercooler?

Regards
Max P

I know gratuitous advice is probably not welcome, but what led you to put an intercooler in probably the worst place for it?
There is a reason all intercoolers are at the front of the car.
I have seen on these forums , several posts that indicate that the underbonnet temps of a Defender are excessive as most of the air into the engine bay passes through the radiator the passes the exhaust manifold.It also has a small air volume. It is important that the air has an easy exit from the engine bay and also this is why many cars have front undertrays, which usually only extend a small way back , to create a venturi effect.

Radiator airflow depends on the pressure differential between the front of the radiator and the back. IE the bigger the pressure drop the more air passes through. If you put a scoop on the bonnet you will reduce the pressure differential and odds are on a Defender you will start getting overheating. Even my Porsche 924 Turbo had a NACA scoop , but it was to let the hot air out when parked, not to push air in.
I suggest that you bite the bullet and get a water / air intercooler with the rad placed in front of the water rad, or do the conventional thing and put the intercooler in front of the rad. You may still increase the load on the water rad but this effect would be less than the effect of unbalancing the pressure gradient in the engine bay.
Regards Philip A

cheers for that info, this was the only easily placed area in the engine bay for it, i know not the best, but going to prob put thermos behind radiator, when i can afford a winch that will cut into the grill and go infront of the radiator, there's no more room in the engine bay.

Putting a 8" fan under the intercooler to pull air down when at slow speeds, and a backward scoop out the passenger vent in the guard. want a small scoop on top to push down whilst highway driving, then will have a cycle - from bonnet through i'cooler and out guard. may have to opt for a grill style, just would prefer a scoop as i thought this would give more cooling?

That sounds OK but you will still have heaps of radiant heat from the exhaust. I assume LH manifold Tdi.

Why not pull in through pass heater vent with a forward facing vent ( you can get beyootiful stainless things in UK), have the fan and have a duct down to the underneath of the car.maybe 3 or 4 3 inch hoses from under the fan. And lots of insulation.
regards Philip A

http://www.d-90.com/mod/hood.html

yes those vent holes are hot, i think i'll run with them as well!!