is that the fan running at its full speed, ie are you running through the switch. Even with the holes, that's very good output. I'm guessing that when the dash and carpets etc are in it will be much quieter. I think you have done a great job.
Now while you wait for the monster motor, you can build more of them for us
Simon yes that was running off a half dead battery I have so wasn't at max power, I wired it straight to the motor however i have also tried it via the speed control and all 4 levels work.
Remember that the sound you are hearing is also the air rushing into the plenum from the scuttle area, as in NO WINDSCREEN LOL and yes once the dash is in and all the carpets etc then the noise should be dampened and not bouncing off bare metal.
Like I said, happy to do so on an exchange basis, have it all down pat now but I have to change some things in the tutorial as I modified the design about half way through.
Was reading Johnny RBZ's upgrade to full electronic climate control today and gave me an idea, so I'm looking at retro fitting a 180SX unit as pictured with full actuators replacing the vacuum system.