Q5 Calipers on a Q3

[SonicRings]

I tried posting this in the Q3 section but that seems pretty much dead. I am wondering What year q5/sq5 brakes will directly bolt up to my 2023 Q3? What rotors will be required for this to work?

- Randy

[ozdi]

Hi, very creative question you asked!..... But please don't swap brakes of different car models. In brake system design, brake calipers, pads, booster, rotors , mounting radius & ABS are tuned to suit specific vehicle. All cars have different wheel base length, different weight and weight distribution, different suspension. Under dynamic braking force, the front / rear weight distribution will change. In correct calipers may not be able to stop the car effectively or may prematurely lock the wheels causing the vehicle to lose traction/steering controls.
Apart from braking performance other issues are also important such as noise, paddle effort, responses. For safety reason, don't do it!

[xRenesis]

Why does that look like an AI response?

I would be willing to bet not many people are changing calipers on a Q3 which is why the lack of answers. However, thousands of people change calipers and rotors to larger sizes to meet various needs without changing ABS, bias, etc. Pre-ABS, locking up sure. Look at the various options we have for the same chassis now lol. SQ5 vs Q5, A4 vs S4, subtle weight differences yet different brake options. It isn't some vastly huge safety reason...

You would probably need to try things yourself or make something. Better pads if nothing else.

[ozdi]

No, its not AI response! I tried to point out the safety concern when changing brake. I worked in brake system R&D for few decades before retired. All designs are NOT based on trial & error. Everything is calculated, tested for performance, safety and durability.

[spijun]

No, its not AI response! I tried to point out the safety concern when changing brake. I worked in brake system R&D for few decades before retired. All designs are NOT based on trial & error. Everything is calculated, tested for performance, safety and durability.

How do you explain that owners of Q5/A4/A5 brake models with 320mm discs changed and installed 345mm, 365mm, 380mm or 390mm
They even used the brakes from the Porsche Macan because it's the same platform

FYI Q3 uses different brake sizes: 312mm, 340mm, 374mm and 380mm