Thread: Bonnet scoop on RRC

Hi Baggy, I found it!! (after searching for about 30 minutes!)

HMLR (Heavily Modified Land Rovers) public group | Facebook

The FB group is called Heavily Modified Land Rovers....

Cheers,
GG

I'm pretty sure the base of the windscreen/scuttle is a very high pressure zone. That is why the ventilation intakes are almost always there

seeya,
Shane L.

Originally Posted by DoubleChevron

??? This is just plain bizarre. If someone doesn't agree with you ... It does not mean they are attacking you. Everyone has an opinion ... That's fine with me.

This is what I mean .... when I try stuff... I'll say blunty "well **** .... that didn't work and cost me a lot of time and money". with regards to melting CD's. I must have what is one of the hottest cars ever made to travel in ( crappy ventilation and way to much glass area). So when I tried to verify that any changes I made actually worked. I finally found at one change that did help heat soak:

citroen cx insulation

The guy that makes the stuff liked my findings so linked them to his website:

EZ Cool Automotive Insulation heat barrier and noise reduction for cars, trucks, classic cars, street rods and much more

I have also obviously used the same stuff on the floors, firewall and transmission tunnel of my Rangie ..... You know, towing in heat, the transmission tunnel still gets bloody warm. I'll have to figure a way of laying more insulation over the gearboxes big rubber gasket.

In your case. I'd pick a day like tomorrow (38degrees).... hook up the caravan or loaded car trailer ... and go for a 20km drive out of town down one of the quiet roads and record the temperatures the car runs at. Then block the bonnet vent and do the same 20km drive and see what the differences are.... Then do the same thing through town. I'm pretty sure you will find an improvement in temperatures sitting in traffic. But towing at speed it really going to suck big time.

seeya,
Shane L.

You're right there, Shane. Standard Issue AULRO discussion deterioration, complete with moderator not quite understanding the point. The only reason I'm still on this pub-argument-styled forum is because I can't be bothered putting together my own website!

You're also right in the post above. Where the airflow over the bonnet meets the windscreen is high pressure and there's no point trying to extract air out of the engine bay there. Anyway, in response to a lovely PM from someone the other day, I will attempt to finally get around to putting together a thread on this hilariously confusing subject.

Originally Posted by Davo

You're right there, Shane. Standard Issue AULRO discussion deterioration, complete with moderator not quite understanding the point. The only reason I'm still on this pub-argument-styled forum is because I can't be bothered putting together my own website!

You're also right in the post above. Where the airflow over the bonnet meets the windscreen is high pressure and there's no point trying to extract air out of the engine bay there. Anyway, in response to a lovely PM from someone the other day, I will attempt to finally get around to putting together a thread on this hilariously confusing subject.

So, say if I'm wrong, are you saying there is a high pressure area above and outside the bonnet, at the base of the windscreen, and so hot air from inside the engine bay would be restricted from exiting through a vent at the rear of the bonnet? Interesting.
That may be why Rangies have their vents on the sides of their mudguards instead.
And I take Mick's point that a forward-facing scoop may be useful to push air into a top-mounted intercooler. However LRs use front intercoolers instead, to avoid the hot air at the top of the engine.
It's all interesting. I've learnt a lot on this thread. Thanks to all.

Yes, yes, and yes again. I know this because I've done so much reading, so it's not just an opinion, it's a fact which can be backed up. Very important with aerodynamics.

I tried posting a picture a few days ago to help with this, so I'll try again:

JaguarExahighres15cropped.jpg

And even though it's a modern design, the basic principles still apply.

Originally Posted by Davo

Yes, yes, and yes again. I know this because I've done so much reading, so it's not just an opinion, it's a fact which can be backed up. Very important with aerodynamics.

I tried posting a picture a few days ago to help with this, so I'll try again:

JaguarExahighres15cropped.jpg

And even though it's a modern design, the basic principles still apply.

SoDavo, from one of the many that hope you will stay and continue to pass on words of wisdom - a thought from left field.

I haven't got my beastie around to check, but is there room anywhere in the bottom of the rear front mudguards of an RRC to mount exhaust fans, possibly even with venting to attract/exhaust from up near the rear of the bonnet?

The other thought, which properly belongs in the other generic thread, is the airflow differences arising from TD5 as opposed to V8?
Of course just to be different, I have a TD5 in my RRC anyway.
Cheers

G`day , its got some pics and basic understanding of where air goes is not temperature specific .

Page 2 and 3 are best probably but the scoop is an intake scoop not what is discussed here it does suggest what goes on at the sides .






Car Aerodynamics Basics, How-To & Design Tips ~ FREE!

Originally Posted by gavinwibrow

SoDavo, from one of the many that hope you will stay and continue to pass on words of wisdom - a thought from left field.

I haven't got my beastie around to check, but is there room anywhere in the bottom of the rear front mudguards of an RRC to mount exhaust fans, possibly even with venting to attract/exhaust from up near the rear of the bonnet?

The other thought, which properly belongs in the other generic thread, is the airflow differences arising from TD5 as opposed to V8?
Of course just to be different, I have a TD5 in my RRC anyway.
Cheers

Well, that venting is what you want to have, but without needing fans. The whole idea is to set up the engine bay so that the airflow does it for you. You need to find or create some low pressure areas. Either way, you need to measure this low pressure, and that means either getting the gauge I mentioned earlier, or just a piece of clear hose - one end in the engine bay, and one end with you inside. You put a U at your end and fill it with some coloured water, and the more that water moves up towards the engine bay, the lower that pressure is. Then, moving the other end around the engine bay will give you some idea of what's really happening under there.

The interesting thing about the Range Rover engine bay is that a Holden or Ford from about the same time has so much room around the motor that you could see the ground, so there's plenty of room for airflow. The Rangie, on the other hand, has a short, wide bonnet which makes seeing over it very easy when off-road, but there's not much room for airflow, and that's why I've been trying to improve it. Which I'll have to get back too soon.