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Discussion Starter · #1 · (Edited)
The local dealer brought in a set of the 18" Audi wheels for me. I'm interested in your opinion on their weight and appearance!

I was thinking of using these for a track wheel. I'll be mounting Toyo R888 DOT Competition Radials on them.

The available widths are 8.5" front and 10.5" rear. I was surprised that the pattern is different than the usual 19" five twin-spoke; instead it is has six single-spokes. I don't remember ever seeing a picture of a R8 fitted with these. If you know of one online, I'd appreciate getting a link to it.

I believe they are the same pattern as the "winter wheel" that some of you have may have on your cars (toecutter?). Here is a picture of the wheel:


They felt "heavy", so I weighed one of the rear wheels on my bath scale at 28.5# (only shows to nearest 1/2 pound). TireRack.com shows three OZ racing wheels for the R8 that weigh 28.0, 29.0 and 33.0 lbs each (rear). Does anyone know what the (NA Std) 19" wheels weigh?

[Because I know you will ask: I believe the Audi retail is USD$855 each (front or rear); the USA standard 19" wheels list for $954 each. My dealer was having a 10% off promotion on wheels for March, so the net was about $770 each. The OZs on tirerack.com retail from $950 to $1003 each (rear). None of these prices include the TPMS sensor assembly which is an additional $120 per wheel.]
 

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Great winter wheels!!
 

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The stock 19" wheels weigh 23.5 lbs. They are actually pretty light, and are forged from what I've read. So fellow track rats, the right thing to do is buy a 2nd set of wheels for your pretty street tires, and use the stock wheels for track tires:D
 

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No TPMS bolt on my wheels.MAYBE this is an indication it is forged? '08 R8
 

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Discussion Starter · #5 ·

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Discussion Starter · #6 · (Edited)
No TPMS bolt on my wheels.
Sorry for the mixup. It's my fault for using misleading slang for the TPMS sensor mounted inside the tire.

The Tire Pressure Monitoring System (TPMS) sensor and its mounting is not visible when the tire is mounted on the wheel. The valve stem is metal, and the end inside the wheel has an internal thread. The TPMS sensor is a little box which is fastened to the inside end of the valve stem using a small hollow steel bolt. There is a recess cast into the rim of these wheels to provide clearance for the TPMS sensor. You can see detailed drawings of all this on pages 10 and 11 of self study program book SSP219 (see excerpts attached).
 

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Desperado - as I understand it,TPMS just sends pressure readings to one of your car's electronic control units and this ECU it is calibrated to generate a low tire pressure warning at a programmed pressure setting. If you're using different diameter wheels (18?) and different sizes tires - with different pressures- you might have false warning light - or no warning- unless you reprogram the ECU. Much like programming ABS for different size tires/rolling diameter. Maybe some of the racers can chime in?

While we're on the subject, I was quite disappointed to learn that TPMS does not display the individual pressures. The Pontiac G? I rented even had that, you could cycle through the pressures, front and rear, at any time. Nice feature!
 

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Yes, that's how it works as far as I know. The sensors have a specific pressure below which they raise an error. Audi uses Beru brand transmitters, they are all at 433 mhz frequency. Each sensor has a unique number, and the ECU must be programmed to accept those numbers, otherwise you would read your neighbor's tire pressure when your car is near other Audis like when sitting in traffic. When I bought my 2nd set of wheels at Tire Rack, I had them install Beru TPMS sensors, and then I had to take the car to the dealer to get them to tweak the ECU to accept them. The technician had trouble getting the car to accept the new sensors, he said he had to redo it several times before it took. But now I can swap between the 2 sets with no problems. It doesn't matter which locations on the car where the wheels are mounted, apparently there's a single antenna for all 4 wheels.
 

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The GM sensors report "RF32:LF34/RR:32:LR:33" so the sensors must be "aware" of which wheel it is monitoring. I wonder how that works rotating tires - when RF becomes RR and LF becomes LR? I guess there are tpms and there are TPMS!
 

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When R.f. signal is reading rt.fr. leading to P.M.S.!!The Pontiac "G" spot is nice though
 

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Discussion Starter · #11 · (Edited)
There is a separate antenna for each wheel. It is a strip located in the top of the wheel well.
 

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There is a separate antenna for each wheel. It is a strip located in the top of the wheel well.
I think I get it, the sensors are tuned to receive signal from a limited range - so they don't pick up the other 3 wheel's data. That makes me believe the ECU is monitoring independent pressures but Audi is just just displaying a LP warning light. Cheap.
 

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Desperado,I was into my fenders and did not see any sign of any antennas. I only went as deep as a front bumper removal. Meet you for lunch in a couple of weeks so that you may Q C my work!! Sounds like Audi might be using some old stock parts? We expect the best! ...Anyways ,check out gallery for pics of the finished 19's.
 

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Discussion Starter · #14 ·
The pics I posted of the wheel well are generic. I confess I'm not 100% sure of the location in the R8, but I believe that is where the antenna is located.
 

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Discussion Starter · #15 · (Edited)
UPDATE:

I sent back the 18" wheels. [Kudos to my dealer and Audi for allowing the trade-in, considering they came special order from Germany. These guys always treat me special, and I appreciate it!]

I exchanged them for the stock 19" rims. The rims are $100 more, and the tires are $50 more (each). Oh well...

The 19" rear wheel weighed 25.5 lbs on the same digital bathroom scale that weighed the 18" rear at 28.5, or three pounds lighter. I'm waiting for the R888 tires to come in, hopefully I'll have them in time to take them to the SoCal Audi event in Spring Mountain, NV this weekend.
 

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New wheels Forged??
 

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Discussion Starter · #17 · (Edited)
New wheels Forged??
I don't know how to tell if they are forged or cast. Can you tell from these pictures? (These are the stock 19" rims that came on the car.)
 

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18 inch wheels will almost NEVER fit an R8 unless they come from Audi or you know for sure they work on a Gallardo. The brake calipers are just too big for almost all 18" wheels to fit correctly. If a salesman tells you that their 18's will fit a R8, be very skeptical. If you do actually SEE a cool 18" wheel on a R8, please post it.
 

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Discussion Starter · #19 · (Edited)
18 inch wheels will almost NEVER fit an R8 unless they come from Audi
I agree.

That is why I purchased the 18" Audi wheel. I am told it is the "standard" wheel on the continent, with the 19" being an option. In North America the 19" wheel is standard, so we never see the 18s.

If you purchase the Winter Tire Package from the Audi Dealer, my understanding is that it will come with the 18" rims shown in the first post above (except the rears will have 5mm more offset, moving the tire deeper into the wheel well).
 

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That 18" style might look nice in 20" size. The stock wheels' openness really lets the calipers get air. I expected calipers to be super hot after driving. But cool.
 
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