Not much man. I noticed it more when I first put in the fuel pumps, but now I hardly ever notice it.
the Walbro being the internal fuel pump makes more noise inside, but I consider myself one of the lucky ones or something b/c it's REALLY quiet inside. It used to make more noise inside after a break-in period but for the last 3 to 4 months at least, I haven't even heard it. I know it's working b/c I can hear the noise on the outside of the car. (I know it's the walbro as well b/c I installed the in-line fuel pump later) I do hear the fuel pumps outside, but it's not at all an annoying noise. It's more like....a cool high-tech whine noise. I really can't give the noise any justice by trying to describe it. I think calling it a "whine" is probably a misnomer to a large degree. More like a high-pitched very pleasing hum.
It's nothing you would associate with a POS car that's not refined. I just think it reflects the high tech nature of our cars is all.
Call me weird or something, but I like the sound of the fuel pumps. Don't ever let any fuel pump noise be some sort of distraction to getting a turbo system. That's ridiculous.
BTW, it's JasonESi_"T"
Jason 98' Eagle Talon ESi-T Mitsu Super 16g Turbo(HRC)