Wheel fitment experts needed

[BBGT2]

Guys,

I am looking into getting a new set of Iforged wheels for the beast.
I contacted Iforged and asked for the widest fitment possible for the RS6 and they came back with 19X9 for the fronts and 19X10 for the rears, which is what I wanted to hear. BUT, how and will the different wheel size widths mess with the Quattro system as well as the rest of the electronic control features the car has.
I am hoping none as I would love to give the car a nice wider stance that makes it look more agressive. I dont and will not track the car at any time so this for me would be a cosmetic change.
All inputs are welcome.

Thank's

Bajo:addict:

[BBGT2]

33 Views and no replies, hmmmm.
This cannot be unchartered teritory for you crazy modders out there.

Still I have faith in this board as it has helped me out before.
Its no hurry, I am bored and been checking the site.

And oh BTW THIS IS NOT A APRIL FOOLS JOKE THREAD !



Bajo:addict:

[AndyBG]

Bajo,

all i can tell you is that i now a guy ho was ''smart'' enough to put diferent size wheels on S8, just for some 10 - 15 of km's, guess what hapend, tiptronic was ''murdered'', some big EUR damage for his wallet.

Just my 0.2 cents, as you say.

Pozdrav!

[BBGT2]

Andy,
That is what I am afraid of and that the Torsen center diff. would go cuckoo over the wheel difference. But wasnt sure.
Just gauging opinions here.
And as for the .02 cents it is now officially .03 cents due to inflation :D , (malo sale).

Pozdrav,

Bajo:addict:

[s42ski]

Bajo, I read on this forum a link to a guy in So Cal that had worked this type of set up with an Audi S4 . The trick was to keep the front and rear total wheel tire radius the same. I think the problem with the beast is there may not be enough
selection" of XL rated tires to make this work.

My 2 cents : Unless you are out of warranty I would not go down the different front and rear wheel sizes - especially with the RS6 tranny being a "weak link"

[BBGT2]

Thanks guys for your inputs.
I read 2 stories similiar one with a guy that completely made his A4 avant look like the first gen RS4 and used 19x10's on all corners:eek: . I asked him and he said he had no issues with rubbing driveability etc. Another guy I read about was with his custom made BBS wheels for his S8, and had diff. wheel widths front and back. He said the same thing as you s42ski about the keeping the same rolling radius and he also stated he had no issues with the Tippy/Torsen drivetrain.
I duhno what to do so I will take my time with this and see what transpires, I will keep asking Iforged, Tire rack, BBS the same questions. Problem with the RS6 is that it is not a S4 and there isnt thousands of them here where guys modded the hell out of them and alot kept them stock, ie supply and demand.
I am hoping some Euro guys input as there were many more sold over the pond.

Bajo:addict:

[GoFastKindaGuy]

I was warned by Audi, "Do not change widths front to rear." So I did'nt. Had another problem:

I went with 19x9 Kinesis with Dunlop SP9000 tires, at the exact same rolling diameter, all the way around. There was 3/8 inch clearance between the tire and the suspension. No evident rubbing. However, I had a blowout from inside sidewall contact with the suspension -- fortunately at low speed. Inspection revealed the same issue on both front tires! There must be way more deflection under load than I ever imagined.

There was no comfortable way to rectify this except to send the wheels back to Kinesis. They put new inner rims on my wheels making them into 19x8.5s. I now have over an inch of inside clearance.

Never again will I attempt cosmetics over function.

[nene]

Sorry Bajo for failing to respond earlier as I was on vacation.

The RS6 allows for very small margin of error when it comes to wheel width and offset. I know this because I've been going at it for way too long, and there aren't many wheels in the market to work with.

As stated before, the wheel and tire combination rolling diameter has to be within 3% of each other. For folks on the B5 S4 forum, as well as my own setups since 2002, I have yet to have any Quattro issues.

You only get identical rolling diameters when both wheel and tires are identical. For different wheel and tire sizes, you can get pretty close, at least where the rolling diameter difference is only 0.5%.

Personally, I would not recommend going the widest, unless your car is simply a show car. If you plan to drive it daily, my recommendations is to stick with 8.5/9 inch front, and 9/9.5 inch rear setups. Reasons for this are that you have a few more choices to go with in tires, and additional room in the wheel well to prevent rubbing. I personally think that a 10 inch wide wheel is asking for trouble, even if your tire is round on the edges. Round edges offer no protection for the rim lip.

http://www.rsracing.com/images/tech-wheelfit.gif

Here are some measurements I took from the wheel wells for your information. If you look at the image above, I measured the front and rear distance between the inner edge of the fender and the first obstruction inside the wheel well, which is the suspension. Measurements are the following:
Front: 9 1/2 inches
Rear : 10 3/4 inches
According to what iForged salesman told you, the 9 inch front and 10 inch rear will work. However, now keep in mind that your offset has to be a whole lot more precise, as you have less room to work with. Given that iForged creates the rims with any offset you want, it may be okay for them to guarantee that. However, I am very skeptical that they have accounted for the tire width. Pilot Sport IIs for example, have a sidewall that tends to be flat. Other tires have sidewalls that are rounder. You can play with sizes of the tires, and as you go larger they get more expensive, and being precise with measurements is hard to do unless you have a friend with a tire shop.

Tires become an important piece of your measurements, as you must make sure that you have an extremely similar rolling diameter. Going with different size wheels, forget about them being identical right now. Just get them to be at most 1.5% different, and be happy with it.
Keeping that in mind, I recommend you check with TireRack.com for example, and see what tire widths in your rim size (18/19/20) have the XL rating. You will find that there aren't that many. Luckily you will find some in the 255 to 295 range, which is mostly what we use.

My recommendations:
1. Go with 8.5 to 9 inch front width rim. Offset between 29 to 34. Make sure they have at least 2" clearance for the brakes. This is the measurement from mounting face to the edge of the brake caliper. Smaller positive offset, causes the pushing of the wheel away from the suspension.
2. Stick with 9.5 inch rears. You have plently of space back there to play with the offset, and get 3-4" lip if you want, without going with wider wheel.

Here is a good wheel technical document (http://www.rsracing.com/tech-wheel.html) that may be helpful in explaining some of the terms and calculations that go into getting correct wheel fitments.

Brake caliper clearance is the most important part in the front wheel. If you let me know what you have in mind in terms of wheels, I will gladly help and see if it can be done.
Please keep in mind that water can get stuck in the center of the rim width (iForged and HRE R versions), and it causes the wheels to vibrate real bad. Awesome wheels in dry weather.

[GoFastKindaGuy]

Here is a tire size calculator you may find useful:

http://www.miata.net/garage/tirecalc.html

[BBGT2]

Nene thank you for the great help.
GFKG, thanks for the link and advice i will check it out and send all my questions to Iforged so they understand my fears worries etc.
thanks again guys this is what makes this forum what it is, a great one.

Bajo:addict: