Just was thinking the other day, why don't we see super chargers on Dmax or other diesels? I know they are common on big boats but I don't recall ever seeing one on a truck. Seems it would eliminate the turbo lag. Or we could even set it up with a turbo as well. I know of several boats thats have twin turbo's feeding a supercharged diesel. Just seems like a neat setup to have under the hood. What is your thoughts on this?

Just was thinking the other day, why don't we see super chargers on Dmax or other diesels? I know they are common on big boats but I don't recall ever seeing one on a truck. Seems it would eliminate the turbo lag. Or we could even set it up with a turbo as well. I know of several boats thats have twin turbo's feeding a supercharged diesel. Just seems like a neat setup to have under the hood. What is your thoughts on this?

I don't think you could make enough boost, but there was some old Detroit's with both aSupercharger and a Turbo

Whipple made one for the 6.5 hummer, but unfortunately can't get intake manifolds for it anymore :(

I'd love to have one

http://www.humvee.net/hid/acc/whipple.html

i've seen old yarder engines that have 2 superchargers AND 2 turbochargers. not sure what kind, but cummins V12 comes to mind.

6V71/92 8V71/92 were supercharged and turbocharged. Sometimes twin turbo's into one blower.

They were 2 stroke diesels though, and needed the blower just to force the intake charge in. They wouldn't run without it. The turbo's just made them more efficient.

Blower technology has advanced enough that I think you could probably run a blower/turbo system on the duramax and see some good numbers but you'd have the problem of intercooling the air between the blower and the motor.

It could be done, but it would take some money, and space under the hood which we don't have too much of.

Turbos are more compact for smaller engines and engine compartment space. Since the diesel is a high-flow engine, the turbo is a very economical way to get boost in a small package. Bigger engines and installations use blowers, turbos or both. Our Colt emergency diesel generators on nuke subs were both turbo and supercharged. Marine and stationary diesels have the size/space luxury to got blower or both. As stated earlier, the 2-stroke diesels can't fuel/exhaust without positive pressure, and you can't wait for a turbo to spool up on one of those. There was a marine/hipro shop that was making a supercharger for the 6.5 diesels, I lost interest when I traded mine in for the Max, but I remember it was a pretty big sucker on top of the engine.

Hah! I remembered "Hammerhead" and googled up this:

http://www.perfprotech.com/home/marine-diesel.htm

superchargers actually take power to make power. Since they are crank driven they will rob some engine power. Turbos are basically recycling the energy pumped out the exhaust. So they do not actually rob the engine of power.

Superchargers have been used in the past on turbocharged diesels to help build boost at lower rpm ranges. With the introduction to VGTs the supercharged diesel probably won't happen on a newer electronic engine. Old mechanicals with big honkin turbos on them can definatley benefit from superchargers.

Also superchargers are expensive.

Turbos are more compact for smaller engines and engine compartment space. Since the diesel is a high-flow engine, the turbo is a very economical way to get boost in a small package. Bigger engines and installations use blowers, turbos or both. Our Colt emergency diesel generators on nuke subs were both turbo and supercharged. Marine and stationary diesels have the size/space luxury to got blower or both. As stated earlier, the 2-stroke diesels can't fuel/exhaust without positive pressure, and you can't wait for a turbo to spool up on one of those. There was a marine/hipro shop that was making a supercharger for the 6.5 diesels, I lost interest when I traded mine in for the Max, but I remember it was a pretty big sucker on top of the engine.

Hah! I remembered "Hammerhead" and googled up this:

http://www.perfprotech.com/home/marine-diesel.htm

Someone gave me a link to this place when I was asking about 6.5 blowers:
http://www.marinedieselusa.com/

I'm probably going to go that route this summer. I really don't want to deal with trying to do the exhaust work for a turbo, not to mention the extra $$$

what about a cyntrifical supercharger feeding the turbo

roots/lyscholm would be better, centrifugal generates heat in air and gearbox to get rpm like turbo. turbo would be less power consuming. saw article on net were took heater core and inset into manifold under blower to cool air look good don't know how worked out.

What about a flux capacitor, will that work?

alot of the old detroits used a supercharger at low engine speeds and once the turbo spooled up the turbo bypassed the supercharger completely. They had a pressure controlled door in the intake tract and once the turbo boost exceeded the limits of the supercharger the turbo would take over.

alot of the old detroits used a supercharger at low engine speeds and once the turbo spooled up the turbo bypassed the supercharger completely. They had a pressure controlled door in the intake tract and once the turbo boost exceeded the limits of the supercharger the turbo would take over.
amazing how mis-informed some people are about the detroit 2 stroke cycle engine and thier respective "blowers" to asperate them, not "supercharge" them...maybe later when i am not so tired, i will explain alittle more on the detroit blowers.

What about a flux capacitor, will that work?

Sorry those only work on delorean's):h

What about a flux capacitor, will that work?

My Mr. Fusion blew an O-ring the other day. Can anyone tell me were I can find a good dealer in the west MI area? :muahaha:

The Procharger D1SC I have laying around appears to fit up front where the second alternator belongs.

superchargers actually take power to make power. Since they are crank driven they will rob some engine power. Turbos are basically recycling the energy pumped out the exhaust. So they do not actually rob the engine of power.

.

I am afraid I will have to disagree with you here. That turbo is acting like a weak jake brake. Thus taking power from the engine. I do agree the power rob is nothing compared to a blower but I think with these diesels you have so much power available at low rpm you won't notice the power robbing. I wish I had paid more attention to my Uncle's boat when I was in the engine room. It seems like they were V12 diesels I don't remember if they had one or two superchargers per engine. I do remember him talking about each supercharger having twin turbos feeding them.

I am afraid I will have to disagree with you here. That turbo is acting like a weak jake brake. Thus taking power from the engine. I do agree the power rob is nothing compared to a blower but I think with these diesels you have so much power available at low rpm you won't notice the power robbing. I wish I had paid more attention to my Uncle's boat when I was in the engine room. It seems like they were V12 diesels I don't remember if they had one or two superchargers per engine. I do remember him talking about each supercharger having twin turbos feeding them.

We agree on the surplus power in the engine, but I think you can't even begin to compare the *exhaust braking* loss of a turbo wheel to the actual crank load of a belt-driven supercharger. The VNT turbos may produce a bit more backpressure that straight spoolers, but it's on the backside of closed exhaust valves and probably immeasurable in comparison to actual mechanical drive on a charger.

you mean a weak exhaust brake?

isn't a jake brake the same as an exhaust brake? Seems everyone here calls them jake brakes but I have heard it called both ways? Whats the difference?

Jake Brake is a brand name and is not an exhaust brake.

Don't know all the technical stuff, but jake brakes operate solenoids on the exhaust valves. I believe they open the valves early on the compression stroke before the injector fires.

Someone with more knowledge would need to explain how they work.

Completely different

http://www.jakebrake.com/technology/exhaust.php

http://www.jakebrake.com/technology/engine.php

Superchargers suck. turbos are where the big power is. Much better device. You look around at any racer around the county running real fast with a gasoline engine or diesel engine and it will be turbocharged.

A guy that lives near me had a 272" buick stage 2 V-6 puting out 1350hp.
It was in 3100lbs regal and it ran 5.0@143 in the 1/8 and 7.82@170+ in the 1/4.

Superchargers suck. turbos are where the big power is. Much better device. You look around at any racer around the county running real fast with a gasoline engine or diesel engine and it will be turbocharged.

A guy that lives near me had a 272" buick stage 2 V-6 puting out 1350hp.
It was in 3100lbs regal and it ran 5.0@143 in the 1/8 and 7.82@170+ in the 1/4.

Each has their place. After looking at both I'll most likely go super because of space restraints.

And supers don't suck - they call 'em "Blowers" for a reason :)

Turbo=more power

Turbo=more power


hmmm top fuel dragsters/funny cars running 5000+hp are all supercharged. Its all in the application.

Are you putting a supercharger on a fuel engine?

I think we are talking about diesel and gas engines. Turbo will always be the choice for ultimate power.

Doesn't matter what fuel you run. Like Yibbutkeen says, it's all in the application. Both provide ultimate power.

Most all engine combinations discussed here turbo would be the obvious
choise. Not unless some of you are planning on building a nitro engine.

Turbocharger, more effecient, no belts to fly off

My personal opinion, you are going backwards by putting a roots style supercharger on our engine. Its all about efficiency. The root style supercharger is about 45% efficient-:t , a centrifugal supercharger is around 80% and a turbo is around 88%. The only reason that the root style is still being used in racing(nitro and alky) is because of the high swept volume that they produce. Turbos are the way to go, plan and simple. If you want to get rid of lag, put on twins. :ro)

Application is everything. For each PSI of backpressure, it costs you ~ 2 HP/PSI on our engines at 2800 RPM. You will generate at least as much backpressure as boost. When you start to go off map with the turbo, their advantage drops off quickly. You will also snuff the engine if it gets too high.

The Screw Supers have reasonable efficency that is nearly flat throughout the rev range.

If you are actually working the motor all the time, They perform about the same with a much broader range the Screw Superchargers. If the load varies greatly, the Turbo wins since it does not load down the engine as bad under low load situations.

jperry, I am not saying turbo's are perfect, and don't take energy to spool them, but as noted several times in this thread, there is no comparison in power robbing between a turbo and supercharger. Also I'm not really understanding why you would have twin turbo's feeding a belt driven supercharger? The impeller on the supercharger would be restricted in it's speed by the speed of the engines belt. I am no stranger to diesels, so I would really like to hear more on this.

And yes I do work on diesels that big. I've worked on anything from a Cat C7 on highway truck engine to Cat C175's.

Also I'm confused on your statement about diesels having so much power down low. Diesels are pretty much naturally aspirated in their lower rpm ranges. They don't build nearly as much power down low as they do at their rated points.

:exactly:

Hey Learn something new there. Thanks for the info about the jake brakes and exhaust brakes. I didn't know the difference in them.

Kappa, I don't know why they would have setup those engines with turbo's feeding the supercharger. This boat is a 45 foot Hatteras, and had two of these engines in it. Maybe the marine application is different in the way the engine is not in the moving air like the front of our trucks or something.

I didn't mean to get anyone in an uproar about wich is better or anything. I was just thinking about that boat the other day and was wondering why we don't see superchargers on our trucks. This tread has been very interesting reading to me and hopefully to others as well.

Is it more effective to get rid of turbo-lag by putting dual turbos, or a single turbo tuned for low exhaust flow with a huge wastegate ?

My personal opinion, you are going backwards by putting a roots style supercharger on our engine. Its all about efficiency. The root style supercharger is about 45% efficient-:t , a centrifugal supercharger is around 80% and a turbo is around 88%. The only reason that the root style is still being used in racing(nitro and alky) is because of the high swept volume that they produce. Turbos are the way to go, plan and simple. If you want to get rid of lag, put on twins. :ro)


Show me a compressor map of any turbo you can find that goes over 78%.

In the early 1990's when I was involved in Drag Boat Racing, there was a Blown Gas Hydro, that was running twin turbos, this boat was increadably fast. When it would leave the line, the supercharged boats would allways get out on it, but by 1/2 track when those turbos spooled up, watch out that thing was a hard charging winner.

One day I would love to come up with a electronicly controlled fuel injected/ intercooled twin turbo set-up for BBC mercruiser bravo 1 boat.

That would be the winning set-up.

Was watching the Discovery Channel- they had a big rig running for a record. 218 MPH or so off of a Detroit Diesel 16 cylinder i believe. 2 superchargers and 4 turbos. no mufflers, the exhaust came out about 10" directly from the turbos. TALK ABOUT SMOKE!!!! They pushed it to get it started, really didnt look like it was getting any juice til the turbos spun up.

sblair,

to answer you question yes, putting twin turbo's in parallel is about the most responsive you can get a diesel normally. Now with the new technologies coming out such as the VNT, (Idaho twins comes to mind here) this should prove to be a VERY responsive setup. Using the VNT as the highpressure turbo you can still use the vain control to beat the lag, then build your big boost with your lp turbo.

jperry,

I guess what I didn't understand about turbo's feeding superchargers, is that the superchargers are belt driven so they can't spin any faster than the pulley/belt setup can provide. Turbo's are basically spinning as fast as the exhaust can move them. My only point is that they supercharger usually feeds the turbo. Now that doesn't mean someone isnt' gonna try it the other way around.

kappa9012, what i have seen is supercharger(blower) mounted close to intake(DD) with turbo(s) feeding and then sometype of bypass valve around blower to cut down on heat and air restriction. worked on boats that had EMD 16v149TBI(turbo-bypass-intercooled). made about 3500HP rear crankshaft was stronger steel, think Stewart & stevens built them from EMD parts. if want faster spool up with twin turbo, valve off one to force exhaust flow thru one and then split flow to both. if you make any more HP the power to get there is the cost for that power. food for thought blower on DD does not make or take away HP, it's designed to run with it and won't run without.

Turbos almost always feed the Super. The Super always multiplies the inlet pressure, so there is never a need to bypass it (except to reduce/control boost) For instance, if the Super gives you 14.5 of boost (about 1 atm) then if you feed it 14.5 of boost, you will get about 43.5 out.

This is all with a postive displacement super like a Whipple or Roots.