Quote Originally Posted by kday View Post
The 044 is a beast of a pump. It's also really loud. As I recall, the RS6 fuel pump(s) are modulated so that when not under load they aren't run at full voltage, which mitigates this somewhat. Not sure how that would work with an aftermarket pump though.

Did you check the genuineaudiparts.com for the OEM pump? Probably still expensive, but might be less than your dealer.

Regarding the pump pressure, the pressure varies with flow. I have data showing the 044 pump delivering well over 500 kPa, but that was into a 5 cylinder with smallish injectors.
I do have the 044 Bosch Fuel Pump installed. It is a little loud, specially when you are running low on gas. I haven't had any issues with it. I decided to upgrade it since I was thinking of going with a full stage 4 MTM but was afraid of upgrading turbos since it is really expensive and labor intensive (and I didn't want to mess with anything major unless it was broken . I have Wagners, colder plugs, MTM Exhaust and recently gutted the downpipes. Anyway, I'm not too car technical and wish I could answer more questions about the pump but again, it hasn't given me problems and I have had it installed for more than 20k miles.