Fitting TT wheels to an A4

[ozynigma]

Hi all,

I have just bought some 18x9 TT wheels with the intention of fitting them to my B8 A4.

My current wheels and tyres are 225/50/17 x 7.5 ET40 CB 66.5mm

I didn't do enough research first and I have found the TT wheels have a smaller CB of 57.1mm

They are 245/40/18 x 9 ET52 CB 57.1mm

I have run this through willtheyfit.com website and I may have an issue with clearance to the strut being reduced by 31mm. I will try and measure this gap when the car comes back from servicing at Alba today.

My questions are;
1) has anyone done this wheel fit before from a TT to an A4 or A5 or similar?
2) has anyone machined VAG wheels out to the larger centre bore and were there any issues?

I am currently getting some prices for machining so I can decide whether it is worth keeping and fitting the wheels or whether I should on sell them.

[dylan8]

Why not run custom spacers if you have issues clearing the strut, space them out and get the correct centre bore at the same time

[ozynigma]

Yes that is what I am doing. Wheel Revolution are making the adapters for $125 each. The adapters mean no need to machine the wheels and the offset is corrected.

The S4 has 18x9 ET35 so we are going to trial a 17mm thick adapter to increase the offset. The only issue might be poke out past the standard A4 guards. We might have to reduce the thickness a few mm to balance clearance to the strut and guards.

It looks like this is not a very common wheel conversion. If I had my time again I would buy more appropriate wheels to start with.

I will try and post before and after pics next week.

[Martin]

I don't know what the rules in QLD are but in NSW this effort would fail inspection/compliance due to:
1) the 17mm spacers
2) increasing the wheel width and track by more than 1 inch

[ozynigma]

Hi Martin. QLD has adopted the National Code of Practice for Vehicle Modifications which can be found on line.

Track will only change by 10mm with 17mm spacers so that is OK. Tyre width is allowed to go up by 30% and the manufacturer fits 9" wide rims to the same chassis in the S4 so I should be OK on that too.

The rolling diameter actually decreases by 0.5% for the wheel and tyre so no problems there.

However you are right that spacers are not allowed. Even though In this case they are simply changing an ET52 wheel to an ET35 wheel.

I am comfortable with doing this though as the adapters will bolt to the hub and the wheel will bolt to the adaptor so no floating spacers. Also no one gets inspected in QLD unless they do something stupid.

[Martin]

Good to know you're aware/informed

Track will only change by 10mm with 17mm spacers so that is OK.

So the A4 can be optioned with 19*8.5 rims - that would be the widest reference - so will track will certainly be less than +25mm of that

However you are right that spacers are not allowed. Even though In this case they are simply changing an ET52 wheel to an ET35 wheel.

I am comfortable with doing this though as the adapters will bolt to the hub and the wheel will bolt to the adaptor so no floating spacers.

The code of practice does explicitly state that spacers and adaptors are illegal

Also no one gets inspected in QLD unless they do something stupid.

Yeah - but that's when the authorities and insurance companies can really take a bad day and make it a bad year for you - especially in an accident situation

[ozynigma]

Track is measured to centreline of the wheel so it's a combination of wheel width and offset. The S4 is listed with 18x9 ET35 so unless they pumped the guards they should fit on the A4.

Yes I am aware of the risks. But to deny a claim the modification must materially affect the claim. So if a wheel falls off and I hit something I could be in trouble.