I was thinking about this and wondering if it has been done by anyone here or anywhere for that matter. I'm thinking instead of twin turbochargers, what about a centrifigual blower (Procharger, Vortech, Paxton, etc.) that feeds a single turbo. One advantage would be ease of installation (somewhat) Bolted to the passenger side of the block taking up the space where the aircleaner is now, then feeding directly into the turbo. You wouldn't have to mess with anything from the turbo back. By 1600rpms, when the stock Cummins starts to build boost, you could have anywhere from 10 to 20psi or more of boost just from the supercharger. Zero lag. Am I just daydreaming too much or is this feasable?

Probably get a head unit for under $2000 but you'd have to fab up all the large chunks of aluminum to bolt it up.....Hmmmm

 

It takes HP to turn a supercharger, turbos turn in the free exhaust gases.

Just something to remember.

 

Procharger messed around w/ this on Big Rigs a few years back with dismal results... They called them "Altitude Compensators" lol Truth is: a head unit would have to be a decent size to not be a restriction at higher boost levels. Like an F-1R or F-2 Procharger. These units are NOT cheap. Twins are the more reliable, cheaper route. If you want something that is different though, knock yourself out

 

Those centrifugal superchargers have a linear boost curve, the higher the RPM, the higher the boost. Most of them probably won't start making any signifigant boost until you're already at redline on a diesel. IMO if you were going to run a supercharger on a diesel, this type of supercharger is the worst choice.

If you went with a roots or twin screw type supercharger you could have full boost just off idle.

It would be an interesting project to be different, but I think you'd have just about the same results with twins, and you wouldnt have to be the guinea pig

 

I know Piers (www.piersdiesel.com) has done some play with the idea. TDR thread with pics http://www.turbodieselregister.com/f...d.php?t=126750. I haven't seen any updates on the progress in a while. Seems very doable, but a lot of work and engineering to fit it all together and tune it.

 

Volvo engineered this very idea in some of their Penta series engines. A super feeding a turbo. However there was a clutch on the drive pulley on the super (just like an A/C compressor clutch) that would de-clutch the super at a certain boost level (when the turbo takes over) so it doesn't become a restriction for the engine.

 

I know a centrifigual is really just a turbo running off a belt instead of exhaust gasses. And no power is free, although turbos are probably the most efficient at producing power. A screw charger would seem to be the best "no lag" option, but I'd have no clue how to set that up.
That Piers thread on TDR is very informative. I'll have to finish reading it some other time. Gotta go take care some snow with a different kind of blower ...

 

Someone on here has a cummins powered chevy dually with a super charger and I believe twin turbos. I think he said it makes 8 lbs of boost at idle.

 

I've been wondering just how "free" running an exhaust gas powered turbo. Surely backpressure is increased. I would also like to know if an in-depth study has been made comparing exhaust driven vice other means to drive the turbo. New to this site!

 

One of the hot rod type magazines (can't remember which one) did an article a couple years ago. Used the same engine (gas) and put on a turbo, then a vortech, and then some other type of supercharger. All limited to the same amout of boost. The turbo made an extra 40hp over the others.

 

Your close-let me offer some corrections here. Volvo Penta is the Marine & Industrial Engine branch of Volvo. (No such thing as "Penta Series" per se)
Volvo Penta does this on 32,42,43,44 and 300 series engines. Also the new D6 370 I/O engines use the following design
The air cleaner has 2 outlets. One outlet goes to a "Y", which has a "flapper"valve.
The other air cleaner outlet goes to the Supercharger. The SC outlet goes to the other inlet on the "Y".
The outlet of the "Y" goes to the turbo.
This way, when the SC is running, the flapper in the "Y"closes, meaning all air will go to the turbo inlet, (the flapper closes off the backside of the air cleaner). The air goes thru the turbo, than aftercooled. (seawater)
It really is very simple. All this was done to help the engine perform similar to a gasser, no lag thruout the range.
The Boost level does not determine the blower function.
On the mechanical engines (32,42,43)There is a switch on the FIP that detects rpm, and activates the electric clutch on the SC. It also shuts it off at a pre-determined rpm ( Inboards and sterndrive engines differ here)
It can also sense a call for fast acceleration, as well as a deceleration time lapse-this so the blower doesnt come on when you are attempting to slow down.
To add- the newer electronic versions of the engine (44 & 300,D6) , the SC is turned on & off by the EDC unit. This engine also has the ability to activate the SC to compress air (heat) to aid cold weather emissions at idle.

Y'all ever want to go for a REAL boat ride-you can probably guess whats in MY bilge.....The real fun begins when I overdrive it!