JPTL

Last year, I jumped on a set of hollow spoke Turbo Twists with Proxes R888 to put on the '88 S4 track/DE car, only to find that the 315's on the 11" rear wheels were simply too wide. Bummer.
I had to sell that set, and now I'm in the hunt once again.
I have a budget, so customs are out. I'd like to avoid fender mods beyond some moderate rolling, but I plan to set the ride height and do a track alignment after I get the right tire/wheel setup.
I'm looking at a set of 10 spoke Panamera S wheels, at the moment. There seem to be a lot of takeoffs out there as folks upgrade their wheels, and sets can be had for cheap, compared to other options. Most importantly, the widths/offsets seem to be a good fit for the S4...
..but the rear width seems to be a little on the narrow side (9").
Are 9" rears too narrow for a good track setup?
If so, what's a good setup for what I'm looking for - preferably OEM Porsche, no the lighter side...

FredR

The perfect wheels for your needs would be like mine at 9.5 inch ET68 for the fronts and 10 inch ET60 for the rears.

The nearest you can get to these dimensions in a Porsche OEM fitment are:
Cup 1 design 9.5 inch wide x 17 inch ET68 part No 965.362.128.05
Cup 2 design 9 inch wide x 17 inch ET70 part no 993.362.128.01

Both the above are quite rare and thus difficult to find and anything but cheap when new.

In 18 inch there are a number of "good options" for the rear wheel but not for the front where the closest you can find are typically 8 inch wide ET57 that fall short offset wise [but many use them].

With the correct offset front rim you can fit a 265 section and on the rear a 285 or a 295 section. If the rear offset is ET60 I can guarantee you can run a 285 without a spacer, I believe a 295 will also fit but that will be a bit tighter in terms of inboard clearance [I never ran that combo on my late S4].

If you do go for a 265 up front you will need to restrict lock on the steering rack by using an additional spacer. A 255 up front will give you a bit more breathing space but for the front wheel you need to keep the diameter close to 25 inches [ a 265x35x18 is typically 25.3 inches, a 255x35x18 is 25.0 inches].

If you cannot find suitable stock rims you are then into custom 3 piece forged designs or you have to accept something less than optimal performance wise like the Carrrera 3 design that will limit you to something like a 245 section or maybe even a 235 section depending on the tyre manufacturer.

In 18 inch rims Porsche do not do a 9.5 inch with ET68 that I am aware of and the 10 inch ET65 rims are probably too wide to use up front [some may disagree] but I am not 100% sure on that one.

Rgds

Fred

mark kibort

find a 11" rim with 8" backspacing and the 315s willl fit with just a tad of fender rolling. (better fit will be the 305s with less rollling)
a 10 in the rear will work and you for sure can use the 305s with no issues and just a lite bat roll.
the holly grail of backspacing is 8" on an 11" rim. work the numbers as you want to keep that tire as far outside as you can here.

JPTL

Thanks for the replies. Just the info. I was looking for regarding specs and fitment. I've gathered that my budget is making work back from "Optimal".
Considering what you guys said:

Assuming that a tire/wheel combination fits without rubbing issues, do the ideal front/rear offsets provide the best tracking and balance, while the ideal rim/tire widths provide the best grip?

The reason I ask this, is that I'm currently running aftermarket 18" cups with good rim widths, but "bad" offsets. I'm guessing fronts are 9" ET50 w/245's; and rears are 10" ET45 w/265 - or thereabouts. No fender room for wider tires as you can imagine.

There seem to be slim pickings when it comes to oem Porsche sets when looking for a front offset with a minimum 59ET. I'm trying to keep the wheel set under $1k, and the Panamera wheel set is local to me and well within my budget. But it has 59ET on 8" fronts; and 53ET on 9" rears.
Are these rims too narrow for track/DE any way you slice it?
If I were to go with this set and put the widest set of tires that the rims could take (Proxes for example), would the better offsets not make up for the reduced grip/contact patch?
Should I just keep running what I have until the right set comes along, or give this Panamera set a try?

FredR

JP,

I doubt very much you would get a 9 inch ET50 with a 245 section in the front wheel well without serious fender contact. ET55 maybe but still tightish.

For the budget you have in mind the ET59 with a 245 section will be the best you can expect with an 8 inch rim. The 9 inch rear would be too narrow for a 285x30 section so you would be looking at a 265x35 [assuming these are 18 inch rims]. You may just be able to fit a 275 section if such were available for the tyre brand you have in mind.

Do not forget you can make up something in the grip stakes by using a DOT rated tyre but remember those things are not much use on the streets given they do not last too long. The tyre I am considering at the moment is the Nitto NT-05. For your wheels they do a 245x40 and a 275x35 that would work on your proposed wheels. They also offer their NT01 DOT tyre in the same sizes and such may well be worth researching for the wheels you propose- they are also very reasonably priced but Tirerack do not offer this brand.

Rgds

Fred

JPTL

A little research turned up Mille Miglia 18" replicas with the following specs:
18x8.5 ET52 front; and 18x10 ET47 rear
If the car weren't an hour away, I'd check.
I'm not concerned about street handling, as this is a track/DE car. I would like to find tires that are DOT certified (street to and from the track) like the Proxes R888.

GlenL

Panamera wheels seem heavy. I'd go with Cayman wheels in 8" and 9" x 18" and run those with the tires you've got now. Better offsets and stylish.

JPTL

I'm seeing the Cayman S wheels with a front ET 57. Are there others with a better offset?
Now that you mention weight, is there a site that lists the weights of factory Porsche wheels?

GlenL

Better offsets than what you have now.

FredR

The Mille Miglia are nice looking wheels but with a 52 offset I suspect you would struggle for clearance with a 235 section yet alone anything wider.

The Boxster/Cayman combinations will fit up front, they are ET57 and nothing more, but some homework would be needed for the rears given they run at ET43 and that may preclude the use of a 275 section.

I have no data on the Panamera wheels so cannot help you there. I would not be surprised if they are heavier [as Glen suggests] but I would also want to know if the Boxster wheels are "strong enough" given it is a significantly lighter vehicle than a [porky] 928 that is closer[?] to the Panamera in the diet department.

It is one thing that a wheel will physically fit, it is quite another whether it will work optimally.

Rgds

Fred

JPTL

Thanks for the continuing informed suggestions!
FWIW, I was able to get the actual weights of the 10 spoke Panamera wheels. When compared to the Cayman S wheels, they're pretty close:

• Front Panamera S: 10.0 kilos/22.2 lbs. Rear: 10.7 kilos/23.8 lbs.
• Front Cayman S: 9.8 kilos/21.6 lbs. Rear: 10.5 kilos/23.1 lbs.

So Panamera fronts are only 9.6 oz more than Cayman S per wheel; and rears are 11.2 oz more.
You make a good point, Fred. The Cayman wheels were designed for a car that's lighter than our 928s - even a partially modded DE car.
The Panamera wheels were designed with a heavier car in mind. I'll use that rationale to justify the small amount of added weight as I consider the Panameras.
It's killing me that the rears are only 9". If they were 11" with the right offset - or even 10", these would be a no-brainer.

FredR

JP,

The weights are about what I might have expected- a tad heavier for the Panamera but not much size for size.

Your concern about the rear is somewhat unfounded I rather suspect. To keep the car in balance needs about 30mm difference in section width and you can achieve this parameter with a 245 up front and a 275 on the rear. Our track chaps can better advise you on that one.

Rgds

Fred