911SLOW

996 CUP lid and wing with stock uprights.

What options do I have for raising the wing's height using new uprights?

Who makes them, anybody made their own DIY design.?

IIRC one class race allowed taller uprights but since I am not located in the US I am not so sure which one or what uprights were permitted.

TIA

John

DHI

Sorry John,
You're on Rennlist to provide answers, not ask questions.
;-P

jrgordonsenior

Crawford makes taller uprights for Grand Am cups, I have them on my car with a cup wing. IIRC they are about $350. A lighter,taller option is the 10' cup uprights. I don't know what Motorsports charges for them but my wrench manufacturers them for about the same $350 and they're perfect. Lousy pic but you get the idea....



.

JackOlsen

Mine are not pretty, but they were just about free. Aluminum scrap and a jigsaw. Not a 996, but you get the idea.



A lot of variations out there.

mooty

crawford.

Surfbum

Jgordon, can you pm me your wrench's contact info. those look great.

911SLOW

Well I am allowed to ask 1 question every 3 months. : )




Thanks for the info and the photos gentlemen, I'm leaning towards fabricating my own uprights. Now all I need is to find the right position and height..

JackOlsen

The height is important. (The fore-aft somewhat less so, I'm told.) A wind tunnel is best, but if you've got a data logger, ten bucks for a ride height sensor, and a little time, you can fabricate a pair of 'testing' supports that have segments you can remove, then run it on set stretch of straight freeway out in the boonies, and repeat, lowering it in 2-3" increments. The ride heigh variations will show you your car's sweet spot.

(I was told, on mine, that computer modeling showed steep drop-offs if I went 4" higher or lower.)

911SLOW

Exactly what I had in mind, to cut the oem uprights in two pieces and then install a middle plate/bracket with holes adjustable for height and for fore -aft movement.
I am also considering leaving them there permanently if they don't end up looking too bad..

For those of us with no access to a wind tunnel or a simulator the only way to make this work is by copying proven designs or experimenting with a G-meter, a data acquisition system, sensors, comparing lap times etc etc..

From some information I have from Manthey (who has access to a wind tunnel) my understanding is that usually the roof line is the limit, and they seem to like the wing as far to the rear, as the regulations allow.

JackOlsen

I'm not an expert on this, but I thought the roof line was often the limit for the same reason wings rarely extend beyond the width of the car -- sanctioning body rules to keep the aero from getting too unwieldy. Certainly the small end caps you see in most series are there because of rules.

333pg333

Just to add another topic in context. When playing with wing positions / sizes , how do you 'tune' the front end of the car for the balance? How much difference does extending the splitter forwards make when putting the rear wing higher or further back? As you can see in some of the pics above, there are examples of some wings leaning way back into clean air. It just 'feels' like there is going to be so much leverage applied that something would have to be adjusted to the front to compensate. Well of course this is the case, but do you tune them together or in isolation? How important are Canards and how much bearing do they have in all this?

JackOlsen

It gets complicated. A splitter will improve downforce (which I'm using in the commonly understood but technically inaccurate sense of the term) at both the front axle and the rear. A wing will only push the back down -- and in fact it can raise the front up through a cantilever effect.

For me, this was where cheap ride height sensors made everything much more manageable.

jrgordonsenior

Definitely a black art. Along with what Jack stated I would add that rake, ie: ride height also will help compensate for the effect of a wing, and then there's sway bars to play with.
I would suggest someone who puts a new, large wing on their car add the splitter simultaneously and do nothing else the first session and see what it feels like. Adjust bars, ride height,etc from there.....

911SLOW

In the front I have made a conversion in the center radiator and now it is tilted, bottom holes are closed and air escapes from outlets on the upper side of the front bumper.
This ads 15kg of downforce and together with a larger front lip downforce is increased by a total of 17kg.
This is quite an improvement from the standard GT3 nose that actually was designed to zero lift and not actually produce downforce.


When I had the RS carbon rear wing set with 8deg shims the car was balanced but this setup brought noticeable drag.
I think that the low height of the oem uprights intensified this.

Hence I moved in the cup wing to try and have around the same downforce with a lower AOA and skip the drag.

The problem with the cup wing is that it minimizes rear view hence I am thinking of raising it about 10cm and also move it in a clearer air path.

Fully agree on the black art comment, but at least we have some facts to move around a bit.

We 'll see how it goes.

mark kibort

+1