big spoilers/ small spoilers?

[colt]

Happy Christmas all.
Is their a real advantage to having the club-sport wing package on a car for a track-day or do the masses here leave the rear blade on it's road setting when on track? That rear wing is very heavy when compared to the road version,I think that i might have read somewhere that on the std setting the difference in down force is small? so is it best left in the shed? Or is it the front one that really makes the difference?
Thanks for your informal views!
Cj

 

[clubsport]

Having owned and driven both versions of the spoilers on the same track.....I would have to say there is a slight difference between the 2.

The larger spoiler kitted car, did feel a little more planted and stable at speeds above 100-110mph through sweeping turns as well as extra stability under high speed braking......then again, they were different cars on the same tyres, so that may be partly down to geo???

As far as Porsche are concerned.......

For the basic (small spoiler) version.

The modifications made to the body have reduced lift values almost to zero, at the same time maintaining the drag coefficient of the standard 993.


For the CS spoiler (larger) version.

The modified front spoiler, along with the fixed rear spoiler and adjustable rear wing, produces higher down force at lower drag values.



cd = drag coefficient

caf = front axle lift coefficient

car = rear axle coefficient

Fa = front axle lift (Newtons of force at 270 kmh 0r 168mph)

Ra = rear axle lift (Newtons of force at 270 kmh 0r 168mph)

N = newtons

Small spoiler kit

cd------caf------Fa lift /N------car------Ra lift /N-------Rear wing angle

0.33------0.03-------178---------0--------- 0------------------Fixed!


Large spoiler kit

cd------caf-------Fa lift /N-------car------Ra lift /N------Rear wing angle

0.34------0.00------0----------0.02--------negative 119------0 degrees

0.34------0.01------59---------0.05--------negative 297------3 degrees

0.35------0.02------119--------0.09--------negative 535------6 degrees

0.36------0.03------178--------0.12--------negative 713------9 degrees


Above data from Porsche, you can see that adjusting the angle on the larger rear wing will give "negative" lift or down force at the back end.

As the drag coefficient rises, you would also expect a car with a CS spoiler kit in full down force mode to have a lower top speed.

Porsche have obviously designed the spoiler kit for a reason, but at the end of the day it's academic as well all know that the small spoiler kit is far more aesthetically pleasing than the vulgar CS kit! []




*Apologies for formatting of above data, I had to try to fill in the gaps to make it legible.

 

[Melv]

And there ends the physics lesson! Phew!

Happy Xmas Paul!!

 

[jdpef356]

ORIGINAL: clubsport

Having owned and driven both versions of the spoilers on the same track.....I would have to say there is a slight difference between the 2.

The larger spoiler kitted car, did feel a little more planted and stable at speeds above 100-110mph through sweeping turns as well as extra stability under high speed braking......then again, they were different cars on the same tyres, so that may be partly down to geo???

As far as Porsche are concerned.......

For the basic (small spoiler) version.

The modifications made to the body have reduced lift values almost to zero, at the same time maintaining the drag coefficient of the standard 993.


For the CS spoiler (larger) version.

The modified front spoiler, along with the fixed rear spoiler and adjustable rear wing, produces higher down force at lower drag values.



cd = drag coefficient

caf = front axle lift coefficient

car = rear axle coefficient

Fa = front axle lift (Newtons of force at 270 kmh 0r 168mph)

Ra = rear axle lift (Newtons of force at 270 kmh 0r 168mph)

N = newtons

Small spoiler kit

cd------caf------Fa lift /N------car------Ra lift /N-------Rear wing angle

0.33------0.03-------178---------0--------- 0------------------Fixed!


Large spoiler kit

cd------caf-------Fa lift /N-------car------Ra lift /N------Rear wing angle

0.34------0.00------0----------0.02--------negative 119------0 degrees

0.34------0.01------59---------0.05--------negative 297------3 degrees

0.35------0.02------119--------0.09--------negative 535------6 degrees

0.36------0.03------178--------0.12--------negative 713------9 degrees


Above data from Porsche, you can see that adjusting the angle on the larger rear wing will give "negative" lift or down force at the back end.

As the drag coefficient rises, you would also expect a car with a CS spoiler kit in full down force mode to have a lower top speed.

Porsche have obviously designed the spoiler kit for a reason, but at the end of the day it's academic as well all know that the small spoiler kit is far more aesthetically pleasing than the vulgar CS kit! []




*Apologies for formatting of above data, I had to try to fill in the gaps to make it legible.

And just as I thought my head was recovering from Chrimbo[]

 

[ChrisW]

Good to see the information from the Porsche Service Teknik --- thanks Paul []

I'm not sure which I prefer, but my car has the small spoiler set (and did have from new), tho' I'm told it was also used to develop the CS spoiler set ??

I also have in the same paint a CS spoiler set which I have not fitted.

 

[Barty964rst]

Not sure of the Physics behind the following observation;
'The CS kit looks quicker than the standard spoilers!'

 

[ChrisW]

ORIGINAL: Barty964rst

Not sure of the Physics behind the following observation;
'The CS kit looks quicker than the standard spoilers!'

I agree, though maybe a little "Escort Cosworth" []

 

[paul howells]

I have been through the exercise!
With all the data porsche produced,only two tracks could i feel any more planted with the cup rear spoiler at full tilt,spa and Thruxton.
Best combo i found on the rs ,was cup/Cs front spoiler and standard rear,worked really well,especially at the front.
Dont know how porsche get the figures,the rear spoiler must produce a lot more drag with the two inlets,which go no where.But they must be right?

GT2 racers,mine with 550 bhp would not go any faster than around 175 because of the drag,high rear wing fitted.Was thinking of fitting just the road gt2 spoilers to get the top end faster.Or a proper rear bi spoiler.
A friend with another gt2 racer managed 199mph at the braking point of kemel,with 750bhp and the large factory banna wing,of which was stated causes little drag,well he managed to tear the rear wing off the rear lid going up kemmel in the race!!Even the rear lid mounts had broken and cracked.

 

[vic cohen]

Happy new year paul ......................i can confirm was standard to have rear wing strenghtend with steel brackets .............bluto had been run with Banana and extra stress took its toll..................................Big Boy down Kemmel even with extra of twin plug and big turbos never that quick ................Graeme L got 6 th gear down the Hanger straight in Bluto , i had my eyes closed!
Once saw unprintable speed down Lavant ,no one wud believe it if i printed it ......................just thank heavens it had 380 mm fronts

 

[paul howells]

Hi Vic,happy new year,oulton not far away!
The driver of the racer at spa was disappointed in his date logger,he said the logger must be wrong as he needed to hit over the magic 200!
I tried Orouge in 5th and even 6th,it still would not go any faster up kemmel,to much drag sadly and not enough BHP! Orouge was getting very tricky.