So what concerns would you expect if your have an AXX engine and looking at the HPFP upgrade - APR/Autotech
As I believe the AXX engine cam lobe to be fine, I would say that just faster cam follower wear. As will be the case with any make of HPFP due to the fact the pumps run with a higher than standard spring pressure.
This is a quote from APR's site
ROUTINE FUEL PUMP INSPECTIONOn a periodic basis, around every ten thousand (10,000) miles, APR
recommends that you inspect the FSI fuel pump, cam follower, and camshaft in
accordance with the factory TSB for abnormal wear. If any wear appears to have
worn through the black wear coating on the cam follower, we recommend that
you replace the cam follower. Once this black coating is worn off, the wear rate
of the cam follower and lobe is dramatically increased. Keeping a good cam
follower in the car is critical to the long term operation of your vehicle.
The cam follower and camshaft wear rates on even stock vehicles appears to be
increased over what even VW/Audi has anticipated. We predict that VW/Audi will
either supersede these components to increase their longevity or they will begin
to include this inspection as a part of the routine maintenance of the vehicle.
We also highly recommend on any modified car an increased oil service interval.
Be sure to use oil that is VW 502 00 specification approved, and change the oil
on a regular basis, preferably every three to five thousand (3000-5000) miles.
I personally took my car off the Longlife service about 40k ago, and now change my oil every 7k using Mobile 1 0w-40.