Aero help
 

Hi All,
I need to move the engine and trans oil radiators away, so I'd like to know if these are points of *GOOD* pressure, assuming that I'll open an exit for the air in front of the wheel.

http://i41.tinypic.com/2hn7s53.jpg

http://i41.tinypic.com/2dtyjk1.jpg

PS: engine bay is separate from these vanes
Thank you.

I think those front corners are both high pressure and high flow areas which is why the Porsche 911 and Boxster-S utilize those locations for their split radiators (water cooled models).

http://www.bombaydigital.com/boxster/projects/radiator/
http://www.bombaydigital.com/boxster...s/overview.gif
http://www.bombaydigital.com/boxster...fore_thumb.jpg

Somewhere in the forum is a CFD image of it.

http://en.wikipedia.org/wiki/Porsche_996
http://upload.wikimedia.org/wikipedi...iert_Seite.jpg
http://upload.wikimedia.org/wikipedi...002_911C4S.JPG

radiators
 

It looks like you have unused space on either side of the inter cooler.Since this location is right at the forward stagnation point,it would be the preferable location if you could squeeze the other two coolers into those spaces.

Yes I know some cars put coolers and intercoolers, but could it be that some front shapes could reduce pressure in those points?

The 911 seems to have a more squared front bumper, while mine seems more "roundy" there...

http://i43.tinypic.com/2mhzgh2.jpg

Really don't want to put coolers in a low pressure point...
Thank you.

Yes, you're totally right... unfortunately there is not enough space for coolers there... the grille is almost touching the intercooler's pipes there...

Thanks

If you want a visual pressure representation on cars similar to yours go to Bing or Google "image search" using the phrase: cfd pressure automobile....or similar phrase perhaps more specific to your model and make.

https://www.google.com/search?q=cfd+...w=1280&bih=678


Examples of such a search:
Corvette Racing: Inside the GT2 Corvette C6.R
http://www.corvetteblogger.com/image.../080409_19.jpg

S1.Dynamic // 997 Turbo - aeromotions
http://aeromotions.com/wp-content/up...eb-300x210.jpg

If you find that you are not scooping enough air, you can always fabricate something to do so such as the below, but on a larger scale.

Pelican Technical Article: 911 Carrera Oil Cooler Upgrade
http://www.pelicanparts.com/techarti...oler/pic20.JPG

It's not too late to ask, so here I go..............why do you want to go though all of this work?

Why do you need to move them from the current location?

What is the objective/goal?

Here is that last idea expressed on a Toyota Supra (different year than Wolf_TM's Supra).

Toyota Supra - Type Cars
http://2.bp.blogspot.com/_kSiL_6q6sX...0%2Borange.jpg

It appears to be a corner scoop, yet vented like an "air curtain" to perhaps prevent excessive pressure build up while turning into corners.

I see what you are thinking. To be honest those opening on your vehicle serve no purpose but for looks alone and create additional drag on your vehicle.

You can do three things with those holes:

1.) Close them off and try your best to fit the curve of your vehicle.

2.) Catch the air and route it to your brakes.

3.) Leave it.


http://electriccarsreport.com/wp-con...-Drayson_5.jpg
As you see in this picture they are routing the air around the tire at a nice steep angle.

Exactly what I meant... if i needed some kind of scoop as the position of the bumper openings are in low pressure zone.



I need to increase the oil cooler size, removing the current one in front of the engine radiator.

Thanks

That's my suspect too... but it is also true that Toyota put the airbox feed in the left opening, so probably is not just for looks and some pressure is there...


Not possible! :)


I already catch the air for brakes with 2 duct beside the central intercooler ;)


I'll probably try to increase flow there with scoops like the red Porsche above...

Thanks

Yes, the Fast & Furious Supra uses the Bomex front bumper.
Is usually the zone in front of the front wheel a low pressure one or not?

Thanks

What does the research I suggested you do reveal?

Please post your results.

Note: I think you are on the right track in not assuming all vehicle front ends are pressurized exactly the same.

Porsche moves the radiators to the front for airflow and car balance, if I had a Free Hand in this case I'd try the Porsche plan. Put NACA ducts in front of the rear wheels, move the radiators there and vent the air into the Low Pressure area at the center rear of the car. Then fill in and round the openings at the front. For low drag, the best are always "Smoooooth".

Why would you want to slam air into a vent only to slam it into the front of your rotating tire? That makes absolutly no sense.


http://www.barrett-jackson.com/stagi...nt_3-4_Web.jpg

Where is the air vent in the above photo? Why would you do it if Nascar is not?

It's a Porsche thing, on the water cooled 911's it's radiators, and on the air-cooled / oil/cooled 911's it's oil coolers dumping hot air on to the tires.

They build long lived cars and have won more races than any other make, must be doing something right, right?

Fighting Aerodynamic issues - A car thread... - ADVrider
http://i145.photobucket.com/albums/r...GT2Airflow.jpg

I'm not sure we want to get into why a 200 mph race car is different and compare it to a street car which might get stuck in traffic.

That's a big subject.

More P-car photos:

Boxster
http://www.ggoodwin.net/2010/02/fron...-clean-up.html
http://lh5.ggpht.com/_Zt3oBgkIEjA/S3...0/IMG_0102.JPG
http://lh6.ggpht.com/_Zt3oBgkIEjA/S3...0/IMG_0101.JPG

Appears to be a wheel well liner.

The Panamera Design: Porsche throughout as it slips through the air
http://www.eurocarnews.com/54/0/217/...h-the-air.html
http://www.eurocarnews.com/media/pic...7/1258-web.jpg
http://www.eurocarnews.com/media/pic...7/1253-web.jpg

^ I know this. I am talking about why the OP wants to redirect the air to his tires for no reason. He stated he will not be using it for any reason other than "attempting" to move it to a lower pressure area or trying to make a nice looking air vent that would actually do more harm than good for his aero.

At stated previously his best bet would be if he just smoothed and closed that area since he already stated:

The orginal post minus the images:
I don't know why he wants to move anything, but your deduction may be true.

Still waiting to hear why he "needs" to move anything.

There is a difference between "need" and "want", maybe he meant "want"?

Post #9:
Now the question is why the OP needs to increase the oil cooler size.

Thanks Jeff, I missed that somehow.

Maybe he added a turbo?

I looked it up, found this:
Cooling Components - 1993-98 Supra
I think most people just put aftermarket oil coolers in front of the stock radiator.

Oil Cooler Design Basics | How to add an oil cooler to a car
http://www.enginebasics.com/Engine%2...oilcooler6.jpg
So it already looks like the above image?

Don't the aftermarket ones have more fins and are more efficient?

First of all, thanks all for your interest.
Seems that I need to add some informations.

I'm an engine builder and an efi ecu mapper.
My car is originally turbo, but later it was upgraded (power, cooling, etc) for mountain roads races.
From the logs during races, I see that oil temp has a wide range, that I'd like to narrow to activate specific ecu strategies.
And to reduce the temps' range, I absolutely need a bigger oil cooler.
Only place in front of the car to fit a bigger oil cooler is that vane under the headlight, but, obviously, i'm going to fit it there only if it's going to work well there... that is to say if i'm going to get good air pressure to feed it and low pressure behind it.
Thanks

Looks all the world to me like there is a good area of high pressure to generate plenty of flow through the coolers placed there. If it were a solid area, I could see it being a serious transition area and pressure would be dramatically lower....but it isn't, it is essentially a flat area facing forward. The side or your existing air intake is already going to act as a scoop, so I don't see a need to extend it forward to be more scoopy. The air on the orange Pelican Tech Porsche scoop thing appears to be coming off a large solid area, the turn signal and such, so it would be moving sideways quite a bit. There I can see the need to extend the scoop on it. On your car, the air is being gobbled up by the main air intake inboard, so the air is coming straight into your lower side intakes. I really think it will work well for you. Good luck! Super cool project you have there.

Wolf_Tm, when you have this project completed please return and post the results.

One thing I've seen in the Pelican Parts forum with front oil coolers is the cautionary tale of making sure the fittings are not constricting flow.

Apparently you can have properly sized oil lines and oil cooler, but if the fitting is too small you will not get the full cooling.

Sometimes fitting a larger fitting is all it takes, for example going from 1/2" to 5/8" is a world of difference in some cases.

Thanks for your argument, makes a lot of sense to me!

Last question...
where would you guys open the rear part of the vane to let the air go out against the tyre?
I'd say the inner lower part, given that I have lips on the bumper to decrease pressure under the car...

Yes I will for sure!
Just don't expect them in the near future as I'm a proud member of the lift club! :D



Exactly, that's why all my oil lines already are dash 10, that is to say 5/8"... ;)

Thanks

FYI: For future reference, an aftermarket Porsche radiator venting at front valance.

Porsche Reloaded Style! | Car tuning and Modified Cars
http://fancytuning.fancytuning.netdn...660&zc=1&q=100
http://fancytuning.com/wp-content/up...-7-660x440.jpg

Very good find, thanks!

Looks like they are turning the airflow about 90 Degrees...that would create a lot of drag I'd think.

The exit is about twice as large as the intake, so there would be a drop in pressure.

The air whisking by would bowl it over, right?

"The air whisking by would bowl it over, right? "....???
Anytime you "make" the air change direction, it creates drag.

This is a complex condition to analyze, it's challenging the limits of my understanding to be honest.

There will be forces to overcome as the air diverges in this duct and is blunted somewhat by what ever radiator or cooling exchanger is in there.

My earlier comments were actually concerning the other matter which is reintroduction into the airflow.

The lower pressure air will be slapped back towards the body and not be ejected very far outward I predict.

I suspect that one could make the exit air flow discharge opening too large and lower the pressure so much that it never gets forced though and back out the side. In such an instance the flow may even be reversed as it is when opening a side window at speed. In this situation the air flows into and out of the cabin quite turbulently in a oscillating (buffeting) fashion.

Look real close at the original image, it might not be a 90 degree elbow. I detect quite a bit of bending, hard to tell for sure without a plan view or drawing.

EDIT: It's looking even more 90 degrees here............unfortunately.

http://fancytuning.com/2012/06/champ...sr/#more-20116
http://fancytuning.com/wp-content/up...-6-660x440.jpg
http://fancytuning.com/wp-content/up...-7-660x440.jpg

MORE:
http://www.m3forum.net/m3forum/showthread.php?t=417938
http://media.caranddriver.com/images...s-1280x782.jpg
http://media.caranddriver.com/images...s-1280x782.jpg

Plus some rear end action....................
http://moyanophotography.com/automot...3/default.html
http://moyanophotography.com/automot...ions0513/8.jpg
http://moyanophotography.com/automot...ions0513/9.jpg
http://moyanophotography.com/automot...ons0513/10.jpg

As I understand it, the fan will not draw well because it's not sealed, a pusher fan on the other side could get away with this.

Poor engineering on at least that count.

I interpreted that as 'the ambient air will cause the exhausted air to hug the side of the car'. In any case wouldn't the heat exchanger at the bend change things? It looks to me like a straight shot to the face of the heat exchanger, an abrupt change through it and then a fairly straight exhaust that almost angles forward to where the air sloughs off into the ambient flow.

kach22i -- You are good at finding and/or cataloging this stuff. Anything on the BMW Air Curtain™. I believe it's a tall narrow slot in the wheelwell lip, where the Porsche has a recessed channel that's more external. I also notice diffusers that collect air toward the front brakes without an internal duct.

Wolf_Tm -- You might want to review Autospeed on the Magnahelic gauge: Optimising Top-Mount Intercoolers

Use the search engine, BMW air curtains have several dedicated thread plus several more where they get a mention.

I typically will add to the most current thread unless the older one is more complete or better in some way.