Donaldson

[doo dah]

Not really. Trip was pretty flat, sea level to 900ft in 175 miles so not too many downshifts but at worst it was 10% of the drone with straight pipe between 1800-2200 rpm. Barely enough to notice it over the a/c blowing.

 

[mikeeg02]

Well I ended up ordering a M100465, 4"-5" adapters for both ends since I'm running a 4" tailpipe. It's significantly quieter than the 4" M085171, and drone is significantly less. Now it seems you have to work to find a condition to make it happen. (Right combination of windows open/closed/rpm/engine load). Definitely happy with how this one works. And it's definitely a big old girl lol. No more obnoxious tail pipe whistle at 15+ psi boost. Just standard turbine noise now. Very nice design. Thanks for posting your part number!

And not that it's terribly different, but mines a 7.3.

 

[doo dah]

Well I ended up ordering a M100465, 4"-5" adapters for both ends since I'm running a 4" tailpipe. It's significantly quieter than the 4" M085171, and drone is significantly less. Now it seems you have to work to find a condition to make it happen. (Right combination of windows open/closed/rpm/engine load). Definitely happy with how this one works. And it's definitely a big old girl lol. No more obnoxious tail pipe whistle at 15+ psi boost. Just standard turbine noise now. Very nice design. Thanks for posting your part number!

And not that it's terribly different, but mines a 7.3.

Sweet! Glad I could help. Since I have a Non VGT mine "kinda" sounds like a 7.3........ imp: