[Ben]

Does anyone know off-hand if 17 inch rims will fit over the brake calipers on the s5?
I am looking to buy a set and use them for track days as in Aus (not sure about the rest of the world) the price for 17 inch race rubber is about half that of 18 inch rims and it only gets worse from there.

[DXB]

What rubber you thinking of buying?

[Ben]

Thinking of the proxies, but am open to actual user feedback.

[DXB]

I think the 888's are a great tyre. ive yet to use them on track but have been in a Z3M with them on track and grip was superb. Cheapest track day tyre also.

I have some and they are soft.

[LittleDevil]

I saw S5 with 17' wheels, but there not much room between calipers and wheels.

[DXB]

As-long as they fit LOL.

[Ben]

Exactly. The space between rotor and rim doesn't need to be much at all, just so they fit. Yay for me and track rims!!!!

[Mike1982]

So does that mean you found a set of 17" wheels then that fit the S5? I am in the process of buying my S5 now and intend to track it a couple times a year. Same issue, don't want to spend that big money for tires if I can get away with smaller diameter ones.

[ChipB]

I am also contemplating the purchase of track wheels & tires for my S5. Being able to run 17" wheels would give a lot more flexibility (and much lower cost) compared to the stock 19", or even 18". I already have a set of 18" wheels which I use in the winter - and in the absence of any positive confirmation about whether 17" wheels fit, I will plan on swapping the snows for track tires for the summer on these wheels. But if 17's would fit over the stock calipers - I would seriously consider buying a dedicated set of 17" wheels and tires for track and autocross - the savings in tire cost and in swapping tires twice/year would make having a dedicated 17" track set up worthwhile. So - anyone tried 17's on the S5 yet?

[Diablo]

Originally Posted by Ben

Does anyone know off-hand if 17 inch rims will fit over the brake calipers on the s5?
I am looking to buy a set and use them for track days as in Aus (not sure about the rest of the world) the price for 17 inch race rubber is about half that of 18 inch rims and it only gets worse from there.

there is a couple of reasons that speak against the 17 inches:

1. The weight of the V8 engine on the front axle disqualifies the 17 inches.
it is the main reason of the minimum 18 inches mount
2. The stiffier S5 suspension
3. Small wheels mean that the heat of the brake systems cannot dissipate the heat by lack of ventilation

You are going to loose steering precision but more important the S5 suspension being stiffer, you will have the higher flanks of your tyres doing excessive work. Your tyres will overheat. This will result in exagerated understeer. You will be fighting through all corners against the lazyness of your car at the entrance of the curves, then the wheight of the engine will emphasize this trend, you will have to lift off instead of accelerating in order to generate oversteer at the exit

What you want on a track is a sharp and precise car with no undesteering and just enough oversteering exiting the curves so that you widen the radius of the curve on acceleration

No fun and no pace! Your S5 does not deserve such a treatment.