mark kibort

the one i saw at laguna didnt have one. do the new 911s with the hood vent, have a radiator there, or are they still in the fenders on both sides. just saw a supercup race where someone had a side impact . lots of water came out. is their a 3rd radiator there? anyway, it doesnt matter, as it makes good sense to use this high flow area to put radiators there. cooling and downforce. I use mine that way, although you still get flow through a radiator without it, as the air goes under the car normally. hood vents do a few things.

mark kibort

If you follow F1 racing, you know that they are allowing an active remote control wing.

Its not a variable AOL, but a section of the rear portion that flaps open, effectively removing angle, area and of course downforce of near 100lbs.

mark kibort

Maybe we need to start just a master aero thread.

Even though this is on a 928, you can see the extent of the pressure zone and is the reason splitters are so effective.

911SLOW

No need to delete anything..

Thread closed.

911SLOW

Gents, on second thought I decided to clean and re-open this thread.

Before posting here (again) please try to respect the rules and guidelines and do not waste time and energy attacking each other, at the end of the day it is virtually impossible for all of us to agree on everything all the time..
Besides most of us are amateurs on this subject and it is pointless to act like we know everything.
From positive posts and discussion we can all try and learn something useful that could be implemented in our cars.

Thanks

John

Bob Rouleau

John, many thanks for the house-keeping. You had to delete a lot of posts!
Folks, please keep this thread technical. I will be watching this thread and I will delete any posts (unless John gets them first) which are demeaning, derogatory or insulting. A number of recent threads have been ruined by such posts to the detriment of the community.

Thanks

onefastviking

Thank you John and Bob,

mark kibort

I dont know what is behind the GT40 inlets, but it is clearly visible that there is no restriction through them. if you notice, now, with a hood vent,all the air that is above the splitter is routed to the hood vents where there is a very low pressure zone. as they move the smoke stream to the side you can see where some of the air is still routed along the front of the car to the sides. amost all of this air would normally just vented under the car.

also notice that the rear wing side plates are trying to keep the high presssure air on top from rolling over and down to neutralize the low pressure zone on the bottom. it rolls after the side plates when it cant effect downforce.

You guys have got me worried about mine, as I have a 6" splitter and have measured .25psi pressure build up on it at 130mph and and it trapping all the air from the nose to the splitter like a vet might do. it is held up with 3 little wires. Im getting a little nervous about going to cal speed way until I can prove to myself that it can handle 160mph, so I will probably test it on some close road.
what usually will happen is that any measured value usually goes up with the square of speed, so from 130 to 160mph is 23% more, so I had better plan on 50% more pressure at 160mph. (or near .25 going to .4psi)

Great video of the GT40 windtunnel test.

http://www.youtube.com/watch?v=3EjFkPL_H_4

The question I have in my mind still, is the one that someone brought up regarding the DP cars. you would think that the slant nose shape of the entire front, would be like a giant dive plane, and not need to route air through and under the nose area to vents . It would be great to know more about their downforce components up front.

kurt M

Big water filled radiators behind the intakes on the GT-40. Don't look like they are an air dam to me.

Notice how dirty the air is by the time it gets to the wing and how the angled outlets in the hood do almost nothing to direct the air around rather than over the car.

I need bigger end plates.

JackOlsen

End caps are like free wing. The only trade-off is drag (see those vortexes at the very end of the the GT wind tunnel clip?).

There's a way to get the benefit without so much drag, but I've only seen the research on winglets for airplanes, which are pretty much only focused on drag. I think larger winglets, at similar angles, would probably be an improvement for automobile use, but sanctioning bodies would have to relax their height and width limitations, which probably isn't ever going to happen.

Here's the airplane style ones. Less drag, theoretically -- but I had no way to test that.

Testing and fitting:



With the black:



The research:



Saving fuel:

mark kibort

yes, there is a little drag on the plates themselves, but the fact that the high pressure zone on top of the wing rescuing the lower pressuer zone on the bottom doesnt happen until past the wing leading edge. you should see the vortex's when you dont have end plates . they are much larger. Plus the drag, over all numbers, are higher without the plates.
as you say with the winglets, with the end plates, you effectively get more active wing area. like using a bigger, or higher aspect ratio wing!

the problem with the Jet version, is that they are designed for a very low angle of attack and very high speed, so the drag savings for a jet will be substantial, but on a car, not so much, because there is not much drag due to lift anyway at at the speeds we travel at on the track. you might want to get some plate coverage, toward the front . the high pressure zone can bleed over the outer edge and spoil the air flow on the outer bottom area. How much gain you get , would be interesting to see in the wing modeling software.

winders

This is the route I am going to take for a wing:

http://www.goodaero.com/JSG/GOODAero.nsf/Products?Open

The Talon....

Scott