mpesik

Hello everyone. I've always been curious about the GTS wing. What difference -than S4,other than paint? Anyone familiar of Mr. Kiborts' wing?(red car). It looks to be heightened about an 1.5". Looks very well proportioned to his rear. How did he fabricate it -from another wing?,and what does it look like close up? Mike.( Not the most exciting post, but things seem to be a little slow in 928 town.)Anyway-this question has always been in my bean and won't stop bouncing around. Thanx for reading.

Nicole

To the best of my knowledge, the only difference between the fixed S4 and GTS wing is the surface coating - S4 is a structured matte black, while the GTS wing is smooth and either painted in body color or (optional) in matte black. There was an early S4 wing that could be flipped-up for cleaning. They gave up on that idea pretty quickly.

Mark Kibort has a kind of spacer between the hatch and his wing. It lifts the wing and tilts it up a little for downforce. He found out that the standard wing by itself does not create any downforce, but lifting it up and tilting it a little does. On the downsied this increases drag and as a result, you have a slightly lesser top speed and higher fuel consumption.

Essentially, what that means is that while the standard wing reduces drag through more efficient air flow, it does not by itself reduce lift or create downforce. However, what we still don't know is whether the revised air flow around the tail (revised by the wing) does any other magic in terms of lift reduction. If it does, it is likely not enough to satisfy any serious racer...

Jeff McVicar

I just picked an s4 wing online for $220 including shipping out of fla.... it seemed like a good deal was it? Just 10 seconds ago haha

MM951

Sounds like a good deal Jeff

Jeff McVicar

cool whew! haha Hey you wouldnt happen to know where I might be able to find a thead on converting the old 83 spoiler to the S4 wing as far as the hatch and quarter glass seals? I've been searching.

mark kibort

I have a "replica" GTS wing that is fiberglass, and I had it painted my car's color.

we did measure tilt vs stock and it went from a couple of lbs up to 80lbs at 120mph with a 9 degree tilt . (about 15-20lbs at 60mph) The spacers I used are the same shape as the bottom of the wing, and they are made from a foam/plastic laminate. we started with 2 , at about .5" each, now we are up to a full 3" spacer. seems its the best trade off for a little downforce and not too much drag. I still think its useless to have a big wing on a 5 liter 350-400hp 928. I think its essential when you get to the 6.5 liter engines and you start pushing 500hp (flywheel).

mk

Jeff McVicar

It said under the notes that this one was fiberglass as well so I guess I'm on the right track. I just need to find out how to change the ouldings to look good and not leak. BADASS car by the way man...... I'd love to spank that one around for a few.

mark kibort

Here is the wing with 3" spacers after PCA laguna 04

Jim bailey - 928 International

You will need rubber 1/4 seals , all new (good used)1/4 trim and all new (good used) rear hatch trim plus clips . The mounting points for the 1/4 spoilers need to be removed and holes filled painted . You are about $500 away from changing to the S-4 wing .

Jeff McVicar

Do you have all the stuff I need?

mpesik

Thanks for all replies. Mr.Kibort,I do love that car. So dimensionally the wing is identical ? 1=yes ,thankyou Miss Nicole. Mike.

Old & New

I never did understand why the extra downforce was necessary. My car seems to handle nicely at all speeds. At >100 it seems to hunker down even more!

mpesik

They needed something to draw attention away from the rear fenders of the s4 and the rear bumper cover. They added the wing which raised the rear line to hide the mistake. After that came the GTS and fenders.Wing was not so superficially important anymore. Tried to update with a colored wing and mirrors (no black band. cheap update) It does'nt give as much of a distraction to the eye as in black . Mike

Doug Hillary

Hi,
Mark - thank you for sharing your data with us in a free manner. It is good for "our" community

Regards

mark kibort

only for that little extra coefficent of friction when you are taking that tight turn at 100mph and you dont want the rear end stepping out.
yes, stock, the down force on the tires is over 3500lbs on our stock cars, and that is plenty for most all street driving. when you get on a race track with some sticky tires, you need a little more , and 80lbs of force pushing down on the rear can allow for even faster turn speeds. Picture Willow springs turn 8-9 at 145mph (decreasing radius 700ft turn.) without down forces, the car wants to head back to LA!


mk