astvic

Hello,

I am considering doing the rear spoiler delete !!!!!

but I can't, until know, find any information regarding consequences of doing it !
I guess that Porsche didn't put it there for fun or ??

I would really appreciate "technical" input on this, before executing

Thanks

Mogens

Nicole

There was a whole thread about this topic...

Porsche always goes through great lengths to balance their cars aerodynamically. Just an example: They made different front lips for the 996 turbo and C4S, even though these had similar bodies and bumpers. But Porsche invested in the wind tunnel work to tune the cars for the different rear spoilers.

Similarly, the spoilers and belly pan of the 928S4 were fine tuned in the wind tunnel - at a time when few other auto makers had or used one. Removing the rear spoiler will likely result in a measurable increase fuel consumption on the freeway/Autobahn, and reduce the 928s legendary high speed and cross wind stability. Remember that your S4 has almost 40 km/h higher top speed than the early 928s that came without that spoiler.

In Germany you would not pass vehicle inspection without the wing. For good reason, I believe.

Jerry Feather

Thanks, Nicole, for the link. That thread sure hits a few of the high points in this topic, doesn't it? Jerry Feather

Ninespub

Nicole, I highly respect your passion, knowledge and as somewhat of a "keeper of archival information" position here on RL.......however I believe that the wing on the 928 is essentially a fashion-induced bling-object and other than the possibility of some downforce at over double the speed limits here in the states, has limited value other than astheticaly pleasing form. I will readily submit to the need of a wing in a racing venue but it is obvious by the typical size used by racers in width, breadth and height that the stock wing is of virtualy no use.

There is a contingent of us who have chosen to go without wings, including some highly respected vendors, long-term members who have done some serious engine modifications nearly doubling their HP and torque, and street cruisers (like me) who may have violated the basic speed laws (inadvertantly, of course) with no ill effect. My/our decision to go wingless was also based upon fashion; just as GTS mirrors and 18-19" wheels have brought our 90's vehicals more in tune with 2011 styling cues.

You and I will probably always differ on this subject but irrespective of that, you have a great day. With best regards.

85euro928

Does anyone have any actual experience with running their car at high triple digit speeds w/o the rear wing? Those are the people I'd be interested to hear from.

mark kibort

it does little to nothing. basically takes the previous body .36 Cd to down to .34 Cd. you will get better gas mileage at 120mph with the little wing.

I put 3" risers on mine and used it for a downforce device, and it did make 80lbs of downforce at 120mph.
stock did nothing for downforce.

I think the avitar pics look pretty good with no wing. very cool Its like a pretty girl with a new hair style.

77tony

Did you say pretty girl ? T

85euro928

Funny Mark.
Anyone have any experience with the rear end feeling loose at high speeds after a wing delete? Deleting the rear wing is on my wish list but I don't want to be the first one to do the field test at speed

SeanR

Yes, quite a few of us have done so, with trained drivers on a closed course. Did not feel any difference at speed.

85euro928

77tony,
That's above and beyond "pretty", you must be an over-acheiver.

85euro928

That's the information I was looking for. Thanks Sean.

astvic

Thanks for the feedback

I think I go for flexible delete solution !

Deleted for babewatch and cruises
and
Undeleted when going to the "autostrada" in Germany

It's all though only 4 nuts and bolts to mount !

EspritS4s

This is an interesting mod, which seriously impacts the look of the car in my opinion. I think that I kind of like it. I also think that it makes the 928 look much more like a modern 911.

Nicole

That would be the mindset you'd expect from GM... However, after speaking with someone who was intimately involved in the 928 S4 design, I can tell you that it is not just contrary to the Porsche culture, but simply untrue.

We do know that a major goal of the changes for the S4 was to reduce drag, which would reduce fuel consumption and increase top speed.

We don't have any data on its role in producing downforce, and can only rely on simple tests like Mark Kibort's "open hatch" test. But even if the wing does not produce any significant downforce, it doesn't mean that there is no lift at the hatch without the wing. Has anybody done Mark's test without a wing mounted? Did the unlocked hatch behave differently at speed?

That all may not be an issue here in the US where gas is cheap, and speeds are limited, but I've heard of people who topped out their 928s on the Öresund bridge between Copehagen and Malmö - that's right in astvic's back yard, so to speak.

I frequently experience the 928s stability when crossing the Bay in strong wind - if I feel the wind and go faster, the car gets more stable. That is exactly the opposite of other cars I've owned, including a similarly shaped Mazda RX-7 that became un-driveable above 85mph in strong cross wind.

For me, owning a top of the line German super car means I want to take full advantage of the engineering efforts that went into it. I don't care, if someone doesn't like my wing - it's part of the package, it balances out the look of the car, and it has at least some desirable function (reducing drag). Form follows function, so mine stays on.


PS: Some interesting opinions from DocMirror:
https://rennlist.com/forums/4443486-post201.html
https://rennlist.com/forums/4446426-post220.html

Ninespub

Nicole: The information you posted by DocMirror was very interesting and I think demonstrates substantial validity to the points that you have made............and also to the ones I have made. In this wonderful world we live in, its all about choices and respect, IMHO. I truly respect your desire, for whatever reason, to choose to keep your wing. I am also comfortable thinking you do the same. My only reason for comenting on the OP's question is because he wanted to make an inteligent choice; to hear the good, the bad & the ugly and then, make a decision based upon the information presented. I think that we both have helped him do that. Enjoy your day and Viva la Whacking the Wing!