Just thought that since we got into a discussion regarding superchargers in another thread that I'd post this video.
YouTube - Supercharged 6.5L diesel startup
I know the question about supercharging a diesel has been brought up more than a few times around here and this is proof that yes it can be done. The engine here is a GM 6.5 but it still applies as it's a custom install. This guy here opted to use a twinscrew charger which is far more efficient than the old roots style blowers. Although they look similar the twinscrew exhibits internal compression as opposed to the roots which basically just "stacks" air in the intake manifold, allowing for greater efficiency when higher pressures are reached. Unlike most modern roots systems they do not incorporate any type of boost bypass valve so they are providing an air charge even at idle speeds. With that said, it still will not run as well as it would with a turbo. It is still a positive displacement compressor meaning it moves a fixed amount of air per revolution, as opposed to a turbo which can spin at various speeds (static boost vs dynamic boost). Sure can't beat that blower whine though

 

Still goes back to the basic you can do anything if you have the skills and dollars.
But which gets you the best return per dollar invested?

 

Right, my point exactly Dave. I'm a diehard supercharger fan, roots and screws are my compressors of choice........on a gas engine. For a diesel nothing but a turbo makes any sense to me at all. Belt driven chargers are generally great for the low to mid range but can't keep pace with a turbo once rpms increase and boost pressures rise. So you'd be helping the diesel on the bottom end (where it's strongest) and as it runs out of steam in the upper portion of the rpm band the compressor does as well. Doesn't seem like a good marriage to me. I believe there is a reason why aftermarket companies don't offer these as alternative kits to the turbo setups yet people still ask if they can strap a blower on their pickup Heck with the way that turbo technology is progressing it's hard to justify using a charger in almost any application anymore. They just make too much power at too similar a cost.

 

The only setup that would make any sense at all is one like Detriot Diesel used.

Turbo chargers feeding the supercharger.

But there is a bit more room under a class 8 hood than we have under ours.

 

Turbocharger hands down for a diesel. I don't care much for gassers anymore so no comment in that direction.

There is a time and place for doing something different, but I just don't get putting a blower on a 6.9. Its impressive maybe, and looks cool depending on who you are, but this one is over my head.

But I'm a little different in that I think an engine that gets 50% efficiency is more impressive than getting better than 1 Hp per CID. Like I said, I'm different.

 

The blower on a Detroit is so the thing will push the exhaust out of the cylinders, it didn't serve any power purposes, a non turbo Detroit is considered a N/A engine even though it still has a blower on it, it won't run without, just the nature of that particular 2 stroke design.

A blower on a diesel only makes sense for a constant rpm application such as the marine engine that was linked to, on something that runs pretty much the same rpm and loading all the time, a constant boost level makes sense, sort of.
Hands down, for an automotive application, nothing makes more sense than a turbo.