Going to be making a start on sorting the bodywork tomorrow which requires a big hole in the side of the new bonnet and nose for the plenum pipework and exhaust.

Also need to consider getting rid of the heat and getting cool air to the filter at the back of the engine bay.

I had vents in the bonnet when the pinto was in, which were just angled slots in the sides of the bonnet at the back. Very effective at letting the heat out, but not so sure on getting cold air in.

But not sure what to do this time.

I quite like the vents in the westfield bonnet



Which would certainly let some cool air in. But then to be effective it would need some holes in the back somewhere to let the air circulate through...

The filter is situated here:


Nearly finished 3

Maybe a NACA duct somewhere on that side of the bonnet would be good?

Any ideas?

vent the sides to allow air to leave below the bonnet line thi will allow a natural flow of air. see my archive

Hi there,

Do you have a floor in your engine bay? I can't tell from the photo. I guess from the question you do have a solid floor.

Matt

p.s. How would you like to be referred to? Flak, Mr Monkey. It seems wrong for me not to try.

My engine side panels stand about 1" from the bodywork which should let air flow through the engine bay.

Can post a pic if you want to see how i'm going to do it?

I'd be tempted to box off the filter and feed as much air to that box as possible, if I were you DAVE... (aka Flakmonkey)

[Edited on 2/4/10 by Steve Hignett]

David, why not do what I did, make an alloy heat shield that wraps around the exhaust as it exit the side of the vehicle. This contains any heat from the exhaust and ducts it out through the side thereby reducing under bonnet temps considerably. You will find pictures in my archive and although you have the exhuast clumped together and stacked, whilst mine are flat above the rail, I see no reason why, with care, you should not be able to come up with something similar.

exhaust heat sheild 2
and

OS bonnet & shield

I'm with Steve on this one, Agree you still need to get the heat out the engine bay but the most important thing is to keep the inlet charge cool hence i boxed my filter in.


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Hi David,
(Properly designed) NACA ducts are the best way to get air in to feed the airbox and I agree with the others that you need to separate the hot air and cold air if possible.

You also need to try to ensure that your under bonnet air pressure isn't too height otherwise the NACA duct won't work. This might require some restriction on the size of the nosecone and/or some side vents.

Alternatively, if you can seal off the area around the airbox in an airtight manner and use a correctly sized NACA intake then you should be good to go. You might need a drain tube in the bottom of your airbox to get rid of any water but if you keep it small then it won't draw in any hot air.

Good luck,
Craig.

As usual, disgustingly neat and tidy in there...

OTT: does the fuel pressure regulator need to be upright like that? Mine may not have room to be upright. I have the same one as you apparently.

Thanks for the input guys. Didnt think about building a box around the filter, looks like thats the way to go for the best result. Will have a look at that later.

I will be wrapping the exhaust with heat wrap, I just havent got around to doing it yet. Another job for later today, been putting it off because its a messy job.

There is no floor in the engine bay, but equally there's not many gaps down there either. Its all a little bit tight!

I concur with the boxing off approach and bore some holes in the bonnet for side air feed.

I used to race a landrover, the filter was placed behind the inner front wheel arch to stop it drowning, but as a hot area the car used to pink occasionally and Megasquirt showed quite high intake temperature.

I just made a few very badly fitting temporary baffles and bored a few holes to the outside world, even without a lot of thought the temperature dropped radically and the car's whole character changed... I was quite astounded by the difference 20 degree's made, you cannot leave as is that’s for sure.

Just cutting a few bits of ali and surrounding with some U trim so they butt neatly against the bonnet should do the trick with a nice vent. My only concern would be induction roar making it hard to get on the track.

Regards Mark

David,

As you're about to do the bodywork and need something to clear the plenum, have you seen how Donkervoort handle the sticky-outy bits?

Hole covered with 3d formed mesh. It might be an idea to have a go with some mesh and wooden formers to try and replicate the look.




For the filter, mine's like that and gets really hot at idle (55-60 deg). Once on the move it is back to abient + 10 deg after 50 metres or so. So whilst not ideal, it would also not be a real big problem to leave it as it is now. Just pay some more attention to the ignition retard above a certain charge temperature.

Boxing it in does seem to be the nicest solution though. Maybe you could do a roadrunnerracing SR2-style intake on the side of the bonnet?

Thanks for the suggestions guys. Will start measuring up for the filter box tomorrow. Will probably run without one for a while as I just want to drive the car and make sure there aren't any major problems.

Few piccies of todays results


New bonnet fitted 1


New bonnet fitted 3

That looks really good! You have a lot to be proud of!