Bonnet louvres for cooling

[Pod]

Has anybody on this board had louvres punched into an E24 bonnet?

I'm considering using the triangular areas above the towers, but there's plenty of room along the centre-line of the bonnet. Any comments?

If so, how effective was it (for cooling purposes)?

Any photographs (or links to E24s with this mod) would be much appreciated

Thanks in anticipation.

[slofut]

Funny, I just saw an advertiser in this months Roundel mag selling these. They were to be riveted in, but to have them punched into the sheetmetal may actually look ok if done well. I had the same thoughts on my jag xj6c years back. There were a couple guys that had them punched and they looked pretty good on those cars. I'd like to see an e24 with them.

[ron]

Lots on here and a couple close to you.

https://www.google.co.uk/search?sourcei ... 5.6739j0j4

[Brucey]

presumably the intention is to let hot air out of the louvres?

If so there is a fundamental problem, in that the cabin air intake is at the base of the windscreen. It is very likely that some of the engine bay air coming out of any louvres will be drawn in to the cabin intake at certain road speeds. [That is why BMW designed the engine bay the way they did IMHO.]

If this happens it might just be a bit stinky, but then again, a small exhaust leak could give you carbon monoxide poisoning.

FWIW if you are going to improve underbonnet cooling, it is probably best to make vents through the inner and outer wings, somewhere near the back of the engine bay. This way air from the engine bay thus won't get into the cabin so easily.

cheers

[Pod]

presumably the intention is to let hot air out of the louvres?

If so there is a fundamental problem, in that the cabin air intake is at the base of the windscreen. It is very likely that some of the engine bay air coming out of any louvres will be drawn in to the cabin intake at certain road speeds. [That is why BMW designed the engine bay the way they did IMHO.]

If this happens it might just be a bit stinky, but then again, a small exhaust leak could give you carbon monoxide poisoning.

FWIW if you are going to improve underbonnet cooling, it is probably best to make vents through the inner and outer wings, somewhere near the back of the engine bay. This way air from the engine bay thus won't get into the cabin so easily.

cheers

Thanks, Brucey.

Ron's Turbo is coming to live with me

I've been researching this for a couple of days. I know that there is low pressure air at the base of the windscreen and I did consider holes through the wings - but thought that this is a big mod. to take on - and I'm not sure if the structural integrity of the shell would be compromised. I came to the conclusion that if I had the louvres punched over the struts, then the airflow would most likely not suck the vented air into the cabin as it would not be "line of sight", if you catch my drift?

Now I come to think about it, I realise why the wing vents and ducting were placed where they are on my ex-AMV8!

I'm wondering if a couple of holes in the front of the inner wings, above the mountings which always rust anyway would be a workable compromise? That would avoid having to cut holes in the outer wings, wouldn't it? (although I accept that the venting would be preferable further back, but then you have issues with the splash guards etc).

Still, I have my recently-acquired plasma cutter.....................................................

Life's never simple - back to the drawing board!

[sharkfan]

Why not just fit the necessary electric cooling fan in front of the radiator, intercooler and oil cooler and see how it all copes?

Going straight to cutting holes in the wings and/or bonnet when there is clearly a cooling system component absent is circumventing the actual problem.

[wattsmonkey]

This has been on my mind of late. The under-bonnet temperature of the m with the fritz manifold is ridiculous. Indeed, I'm sure my sticking throttle is partly down to this and I expect brake mc problems to follow.

I've bought some comedically-named "magma wrap" on recommendation and will be bending a sheet of aluminium to follow the original rhd heat shield. I am tempted to follow the e34 example and fit the steering box shield.

How did the proper snakes nest lhd cars manage?

[sansouci]

Did you look at the solution for the V16 Goldfish? Trunk mounted radiator. Too radical for a 6 but intriguing anyway.

[Da_Hose]

I have a set of snakes in my M6. I could not re-fit the main heat shield, so I made my own. Shape is a replica of the original, but made from expanded sheet metal that can flex, which allows installation with headers mounted.



The steering arm heat shield fits just fine.

Jose

[wattsmonkey]

Thanks Jose,

That looks just the thing.

The rhd cars do not have a heatshield over the steering box as standard, which always struck me as a bit of an oversight. There is one on the upper control arm though.

[635csiSyd]

I run a 300hp turbo mini and have also had stupid hp turbo Lancers et al before you start cutting holes in everything get the exhaust manifold,turbo hot side etc etc ceramic coated you will be surprised at how much the under bonnet temps come down

[Pod]

Why not just fit the necessary electric cooling fan in front of the radiator, intercooler and oil cooler and see how it all copes?

Going straight to cutting holes in the wings and/or bonnet when there is clearly a cooling system component absent is circumventing the actual problem.

As I understand it, there is no room to fit an auxiliary fan in front of the rad. Apparently the car gets too warm after a while when stationary with the existing fan/viscous coupling. Although it should be possible to replace these with a puller fan (and hopefully increase the power output a little ), I see the main problem to be the removal hot air from the engine bay after the cooling cycle when there is insufficient air flow past the car.

I've got plenty of spare bonnets to experiment with, so its not really a big issue for me if it doesn't work. Chopping holes in front wings though, is an entirely different kettle of fish........................

[Pod]

I run a 300hp turbo mini and have also had stupid hp turbo Lancers et al before you start cutting holes in everything get the exhaust manifold,turbo hot side etc etc ceramic coated you will be surprised at how much the under bonnet temps come down

Thanks for your input - a worthwhile consideration. In light of my previous comment regarding a plentiful supply of bonnets, I am minded to do that first which will be an inexpensive and immediate "fix" (I hope ) before getting involved in taking parts off the car which I fear may be time-consuming and not without significant cost. I'd rather be driving the car now and working on it when the Summer ends. (Probably in a few weeks in this part of the World )

[RossDinan6]

I have been considering adding louvers to my hood (I'm a colonist, what can I say). After the replacement fuse box cover warped due to the heat it got me thinking about it. The passenger side paint and sound insulation under hood has been deteriorated for years due to turbo heat. I just can't quite picture it in my unartistic mind. I'd be quite curious the results of before and after temp measurements.

Looks like I may need to record some temps and track down a bonnet.