[GreyGhost702]

Originally Posted by arpad_m

I second (third) that. The noise profile of my LT1 definitely changed with long tube headers, the ticking is much louder than before. With the new forged bottom end, I hear a bit of valve noise underl oad, too, nothing like a sewing machine, just a pleasant little chatter.

The sound my engine emits under boost is not exactly what I'd call "hum", though, it's more of a thunderous roar with a tiny bit of whine.

They just don't make 'em whiney like they used to, LOL. At least Procharger never changes. I did straight cut gears on my '08 Mustang GT D1SC. I thought it was going to have more of a turbine whine but it just sounded like clatter. Don't know how else to describe it. The helicut gears are definitely the way to go. My current D1X will likely get the Royal Purple treatment. I had problems with the D1 on my Mustang, the head unit drank its own oil. The seals were *not* bad, wasted my time (money) sending it to a shop to have it pulled apart and put back together. So I did what many others were doing, and got away from ATI's proprietary whale oil and ran Royal Purple XPR 20w50. Changed that head unit immediately. It stopped eating oil, it ran super smooth, and even had a nicer sound. Still sounded like a box of rocks, but it was a smoother box of rocks. Never had issues with the D1 after that, performance or otherwise. I put 50,000 miles on that blower, about 40,000 was on 20w50. I talked to ATI about it at SEMA back in 2014 but they clutched pearls and practically ran me out of their area. It was blasphemy that I wasn't using their oil and may the car gods have mercy on me and all that jazz. I'm like... if you guys offered a warranty that lasted longer than spit on hot asphalt, maybe I'd give a shit what oil was in it. But since it's on me to keep it operational, I'm personally not a fan of moving mechanical parts running out of lubricant lol. Fun stuff.