Does fitting your front disc brake conversion kit affect the track width?

This will vary depending on the offset of your wheels. Typically:

On Early Split Screen, the track width is increased by approx. 7mm. If using Porsche 5x130 PCD, the track width is decreased by approx. 8mm.

On Late Split Screen/Early Bay the track width is increased by approx. 12mm. If using Porsche 5x130 PCD, the track width is decreased by approx. 3mm.

On Late Bay the track width is increased by approx. 15mm. If using Porsche 5x130 PCD, the track width shouldn’t be affected. If using the 5x112 pattern on the late bay hubs, the track width shouldn’t be affected.