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MG MGF Technical - Air Intake
|Does anyone know if there are any air intakes available that could be installed on the rear wing, above the fuel filler at a 90 degree angle that would duct air straight into an ITG or Rover 820 type pot?|
I realise this would entail cutting a hole in the wing but it is a mod I have seen on various Lotus (Lotii? Lotusis?)
I think it would provide a better, cooler and more direct input without stealing some airlow from the lower duct if that method were used - It would look good too!!!
|You can get air ducting hose from halfords for a couple of quid.|
Expandable aluminium type.
Dont know why you would want to cut a hole in the wing though?
I've got a standard K&N panel filter in the original box but I've junked the original air pipes and ran a hose straight out the bottom of the air box and down and under the car to scoop up cold air there.
When I first had my car on the rollers it gave me 125bhp
|Bob, I think that Kevin is after an external scoop, as seen on some old style MR2s. I've never seen one of these on an F, but it ought to be possible to make something up out of fibreglass. |
|Probebly wouldn't pass the MOT requirements anymore.|
|Why wouldn't it pass the mot? There is enough jap stuff with air scoops etc and there is an external scoop for the elise/excige so what would the issue be?|
It would have mesh inside to stop small boys being sucked in.....
|Kevin, you ought to have a chat to Thierry - he had a very similar idea to you! |
The problem regarding MoT is pedestrian safety: any objects that could come into contact with a person needs to meet certain standards.
At best, you could fail an MoT. At worst, you could end up being sued by your insurance company.
BUT if designed properly, there is no reason why it could not be done.
But why not use the engine air intake in the wing, and use a scoop on that ala Carl's and Paul's mods?
I keep reading that the MGF engine gets very hot, which is bad for the engine, and that the air scoops on the F are not brilliant (TF ones are better?) Therefore, instead of sticking a large piece of trunking into a scoop and robbing that scoop of a large proportion of cooling air, it would be better for the engine (heat) and the intake (cool air straight in, shortest route possible) and sound and looks!!! for it to be mounted on the wing.
It may be a load of C*&p but I am new to the MGF and my eventual aim is a fast road car and maybe a little track day action. I'm trying to find out the best way of going about things and what people have tried and has worked or failed.
|The 'scoop' is air pressure neutral, so air is only 'sucked in' by the hot air rising, but at speed this is lightly to be negligable compared with the air swirling and entering from under the engine.|
|No worries Kevin! You've certainly come to the right place for experience with these cars - most things have already been tried! LOL|
To return to the air intakes - by using it as an air intake will have little or no impact on engine bay cooling. This is mainly achieved by airflow from under the car passing under the sump, and up the back of the engine to pass out of the vents in the top of the boot lid.
There is practically no airflow through the airvents at speeds of 50mph - I've checked: using a video camera mounted in another car running side by side with an MGF with streamers attached, airflow is practically nil or even inversed through those grilles. So no problems using this as an engine air intake. It would work better by using TF-esque scoops over the grilles though... :o)
BTW regarding track days etc, have you come across http://www.mgs-on-track.com/ yet? Might be worth you checking out! :o)
|What happened to the investigation into a scoop under the engine to draw air in from below? |
|Ralph, as Thierry has posted up, Roger Parker looked into this absolutely ages ago, using an MR2 air scoop - pix at the top of http://www.mgfcar.de/air_vent/ |
IIRC the results were fairly disappointing - although Rog had some ideas on how to improve the design and also in terms of how to measure any differences - but then moved from his MGF to a TF (and subsequently on to MGs brilliant saloons!)
was experimenting with extended cooling for the engine bay some years ago. The findings were not as expected ! If one takes away all the bolts for the engine cover and run the car with a passenger that can observe and pull down the engine cover some interesting things will be found!
Even at low speeds (20mph) the engine cover starts to lift due to over-pressure in the engine compartment. At moderate speeds there is a considerable force needed to close it. This is true both with the hood down and up,so really not enhanced by moving air above the cover due to hood down.
So IMO there is enough air for decent additional air cooling (what THAT can be worth is a thread of itīs own ;O) BUT the main problem is to get that hot air OUT ! I have read about the controversy of the rear vents on the lid and what way the air is moving ,but IMO still there is a need for more escape of the hot air than more air entering.
Any proper esigns wellcome!
|Interesting experiment there Carl and this certainly accords with my suspicions. What you have is a large-ish entry under the car and a bottle neck in the top of the boot lid. I am sure that some minor bodywork alterations could make a lot of difference to engine bay temperatures if they were done correctly.|
|I'm not convinced that engine bay temperatures are such a huge issue. If you had a turbo charger then yes, I can see the need for improved engine cooling. But we haven't.|
Remember that the car was hot weather tested in Nevada - and it was here that the boot vents were added in replacement to the bootlid plenum for cooling purposes.
If engine bay temperatures really soared, then the engine bay cooling fan would be on the whole time. It isn't.
The engine is primarily cooled by the coolant circuit, whereas the oil is cooled in the sump that is in the airflow under the car, and presumably some of the oil's heat is also removed by heat exchange to the coolant circuit.
What would increasing airflow in the engine bay achieve?
Clearly I'm in a provockative mood today!!! LOL
|>The engine is primarily cooled by the coolant circuit|
On a lotus elise this is the _only_ cooling
>whereas the oil is cooled in the sump that is in the airflow under the car.
Yep, I guess that alloy sumps give better cooling than steel sumps (they have fins right?). Did the F ever get steel sumps (the midget has one)
>and presumably some of the oil's heat is also removed by heat exchange to the coolant circuit.
Very little, but yes there is some cross over in the head
|don't forget that the 200 HPD had little side scoops and an extra pair of bootlid vents - it was very tempting to try and pull the scoops off!|
|Rob,I think you are correct about the rather small amount of additional cooling of the engine block if there was more airflow. My concern is more about the total engine compartment temperature. Surely a bit more relaxed temp there would bring more moderate temperatures also to MEMS, ignition coils,generator and all the other add-onīs that makes the engine turn.|
Especially for electronics every degree of heat that can be taken away leeds to better time between failure. Not to mention ageing of materials etc. that is also increased by heat.
One can only imagine the problems if the original air outlet(a small slot where normally the third brake-light now is placed) had remained!
But as the summer goes on here in Scandinavia there is little fear of any overheating at the present...
The main subject now is to ensure enough thread in the tyres to avoid aqua-planing ;O(
|>> don't forget that the 200 HPD had little side scoops and an extra pair of bootlid vents - it was very tempting to try and pull the scoops off! <<|
Yes, I noticed those Tony. Might have more to do with styling and the increased alternator loads at idle or low engine and/or road speeds required to power/recharge the electric motor and battery back.
BTW I'd like something similar to those scoops for my F - but for a different reason ;o)
|Carl, your point regarding electrical reliability is well taken - but not everyone who talks about engine bay temperatures being a problem are thinking as you are about this.|
So your summer is looking as good as ours at the moment? Not much chance of a tan here either. Maybe rust though... ;o(
This thread was discussed between 15/07/2004 and 16/07/2004
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