original wheels vs cup repro

[hepkat63]

Hi All,
new to Porsche and to the forum and have a question regarding the replacing of the standard wheels. I have just bought my 1990 964 Porsche C2 and it has 17" repro Cups wheels on it. They look just fine and have good tyres on them.
When i bought the car, the guy also had the original 16" wheels for it - they also have good tyres.
After i got home - i cleaned them all up and they are pretty much as good , if not better than the repro cups that are on the car now. So, i am considering putting the original wheels back on and selling off the cups ones.
My question is (and apologies if it is a stupid one) - apart from looks (and they look pretty similar anyway) why would someone decide to put 17" rims on the car ? I thought that a 16" rim would give a better (factory) ride anyway?
As I said, new to Porsche - so maybe there is some great reason I don't know about?

[964TargaC2]

Tire selection is much better in the 17 inch size

Welocme to the forums and btw we need pictures..we love to see cars!

[hepkat63]

Originally Posted by 964TargaC2

Tire selection is much better in the 17 inch size

Welocme to the forums and btw we need pictures..we love to see cars!

ok, thanks for that - yes, I can see how the choice is bigger, however what are the real difference - like road handling, quieter ride etc?

[Vandit]

I'd say the majority of folks think the 17" wheels look better on the 964 than the 16" wheels, so by moving the 17"s they updated the look to that of later model 964s and also gave the car that RS-inspired look.

Handling will be sharper w/ the 17"s and like was already stated, better tire selection too. With the 16" wheels you'd probably run a 205 in front and a 225 in the rear. The car would be under-tired for serious performance driving. With the 17"s you'd probably be able to run a 225 in the front and a 255 or 265 in the rear. Lots more rubber on the road.

As far as better/softer/quieter ride... there probably is a trade-off, but it's marginal, and really, on a car like the 964... well, lets just say you started with the wrong car if you're looking for a limousine quality ride.

[hepkat63]

Originally Posted by Vandit

I'd say the majority of folks think the 17" wheels look better on the 964 than the 16" wheels, so by moving the 17"s they updated the look to that of later model 964s and also gave the car that RS-inspired look.

Handling will be sharper w/ the 17"s and like was already stated, better tire selection too. With the 16" wheels you'd probably run a 205 in front and a 225 in the rear. The car would be under-tired for serious performance driving. With the 17"s you'd probably be able to run a 225 in the front and a 255 or 265 in the rear. Lots more rubber on the road.

As far as better/softer/quieter ride... there probably is a trade-off, but it's marginal, and really, on a car like the 964... well, lets just say you started with the wrong car if you're looking for a limousine quality ride.

thanks Vandit for that information - all makes sense. No, not after a limo LOL ! Just trying to see why the previous owner put these on the car when the originals were just fine. Tell you though - when I line up the original forged aluminium ones against these cups ones - there really isn't a whole lot of difference - not the $1000 plus he would have spent swapping over IMHO.

[umgang]

weight them.
Unpsrung weight is your enemy concerning handling and feel of the car.
Most after market wheels are a lot heavier than OEM.
Huge difference.

[hepkat63]

Originally Posted by umgang

weight them.
Unpsrung weight is your enemy concerning handling and feel of the car.
Most after market wheels are a lot heavier than OEM.
Huge difference.

thanks umgang for that information. I had not heard of that before and after reading the definition on wikipedia, still a little confused about what it means. So, are you saying the aftermarket wheels are actually better than the OEM ?

[Vandit]

Lighter is better, but unless you're out there trying to save tenths off your lap times, then it isn't such a big deal.

Knock yourself out w/ wheel weight data points.
944racing

You said your Cup 1s aren't OEM, they're likely Mille Miglia, so scroll down further.

[hepkat63]

Originally Posted by Vandit

Lighter is better, but unless you're out there trying to save tenths off your lap times, then it isn't such a big deal.

Knock yourself out w/ wheel weight data points.
944racing

You said your Cup 1s aren't OEM, they're likely Mille Miglia, so scroll down further.

great link - thank you

[umgang]

Originally Posted by hepkat63

thanks umgang for that information. I had not heard of that before and after reading the definition on wikipedia, still a little confused about what it means. So, are you saying the aftermarket wheels are actually better than the OEM ?

Unsprung weight would be the weight of those parts at the corners, but independent of the chassis i.e
things that effect unsprung weight are brake rotors, calipers, hubs, wheels, tires....
picture your car on a lift - the parts that are in a sense "hanging" are unsprung.

OEM would be lighter in most cases.
Fuchs wheels, and Fikse wheels in 16"/17" are going to weigh around 16-17lbs/wheel
compared to
aftermarket wheels like Cup clones, weigh up to 26 lbs each/ wheel!
This is huge and is noticeable to the handling of the car.
Steering becomes heavier, response time slower, slip angles larger = more effort.

Hope this helps.

[lopro]

maybe the larger wheels give the illusion that the car is smaller and larger wheels fill the wheel arches showing less gap from tire to fender providing a more fitting appearance