NJ-GT

I'm curious about the downforce on this wing element at 100mph, 125mph, 150mph.

Thanks

DrJupeman

We should assume you're referring to the later style wing and not the early wing?

jrgordonsenior

More than enough. Too much wing and they push a lot. Oh wait, they push anyway....

95m3racer

Try to find some Shock pot data from a 996 on a straight away.

Are you looking for an exact number for any particular reason, or just curious what kind of downforce its creating?

NJ-GT

I'm just looking for a rough estimate in lbs.

I think that on certain tracks like Fontana, where the infield is so tight, the wing doesn't help much at those slow speeds. At the same time, that wing will hurt the top speed on the Speedway.

95m3racer

Under 80mph you are not getting anything usable. So if you are on turns under 80mph, consider the downforce from the rear wing negligble, maybe 50lbs? It increases exponentially with speed. So don't think 100mph=50#, 110mph=75#, 120mph=100#, it would be more like 50#>125#>275#....and so on. And of course on a single element setup like that the drag is increasing with speed as well. For a Porsche I don't think, even at 160mph you'd be losing more than say 25-30hp from drag though.

If I had to guess, judging from the element size and placement, at 100mph you are probably getting ~150lbs, and at 140 you are probably getting ~350lbs+.

Easy way to determine is slap on some shock pots and do some high speed runs. So if you have a 700lbs/in spring in the rear, you would see a quarter inch in compression under the 140mph/350lbs load (distirbuted to two rear springs). Obviously these are all relative, just guessing...

Anyone have any data? C'mon, I know there are some data freaks out there

Nordschleife

its not a simple trial, as you not only have to make a series of runs at different speeds (and remember to do baselines without anything on the back), you have to do them with and without gurney flap and at all the different angles of attack.
This will take you several hours at an airfield as you need to verify the data after each run. And do each run in each direction, and makes sure that the wind speed and direction is constant (hint wide runway and angle your driving line), or just stick the car in the wind tunnel at Ingolstadt at 3 in the morning.

R+C

jrgordonsenior

FWIW, at Miller 2 weeks ago I adjusted my wing 1-off flat since there were 2 long straight with lots of 3rd. gear infield turns. I run flat at Cal Speedway for the same reason....

analogmike

I tried running my wing flat at Mid Ohio for the SCCA runoffs but braking was too twitchy after the long straight. I would say it's way more than a few hundred pounds of downforce at 150 when it's up full.

Nordschleife

you could always experiment with braking harder initially to induce more weight transfer to the front, so the lack of downforce on the rear is not so noticable.

R+C

95m3racer

But when are you on a turn at 150mph All its doing for you at 150mph is slowing you down.