The right twins setup will get you the same thing. A supercharger would be expensive and pointless (IMO)....let's see, you'd need bypasses, clutches, a whole lot of extra tubing, etc
WITH A SUPERCHARGER PULLEIED RIGHT YOU COULD ACTUALLY MAKE BOOST AT IDLE. AND HAVE THE PULLEY ON A PRESSURE SWITCH AND CLUTCH TO DIENGAGE AT LIKE 15 PSI OND THE CHARGER/S ARE LIT. IF SOMEONE COULD DO IT IT WOULD KICKA SS.
But even with the right twins you would not be able to ger the same kind of boost @ idle that a supercharger would get. The roots & twin screw compressor have instant boost even at idle. Im not saying it wouldnt be expensive. But It sure would be cool!
LOL! It's easy to tell when someone paints themselves into a corner. What books would you recommend? Something on thermal dynamics or perhaps the incompleteness theorem.... I’ll get to those after I figure out the difference between old and modern diesels. I mean I know the injection system changed to common rail with multiple injection pulses and all that jazz. But I can’t wrap my head around how they require different air densities. Because everybody but me knows that 15psi of boost from a supper charger is WAY different than 15psi from a turbo…
They will both compress the air, and at a certain RPM or passing the efficiency rating will heat soak. Density of air has to do with intake temp, supercharger or turbo temp and the efficiency of the heat exchanger being used in the application.
Now I never made any statement about efficiency :S:
...but a turbo’s efficiency is probably its second greatest benefit, second only to their impeccable safety record!
Ok I'm back.... I some what agree with the mopar man but with a super charger you can't change the boost relative to the engine speed like you can with a turbo....
Um......yes u can. Change pulley diameters. It will increase or decrease the speed of the rotors in a roots app or increase or decrease the impellar speed on a centrifugal unit
Yes, Its easy to change the boost level on a supercharger. All you have to do is change the pulleys. Only takes a few minuets and you have more or less boost depending on what size you change the pulley to. To change the boost level there are 2 pullys you could change. The drive pulley on the compressor it self, The lower drive pulley on the motor, Or both.
Yes, Its easy to change the boost level on a supercharger. All you have to do is change the pulleys. Only takes a few minuets and you have more or less boost depending on what size you change the pulley to.
Just a question... but to get the same volume and pressure some of these guys are running i.e. 60-80 psi of boost wouldnt that change the curve and efficiency of a S.C.? If you could even push that with a S.C.? Most i usually see a S.C. push efficiently, even on a 1500 HP merlin block (whipple quad rotors) was about 17 PSI at 8k RPM... Just wondering if you could get 60 psi out of a supercharger? to me you would be limited by drive gear size limitations..
if you had a turbo feeding into it ti wouldnt kneed to make 80 psi right it could just take 50 or so and turn that into 80 or what ever a 17psi blower would turn 50 into right?
The problem is we are trying to compare apples to lemons and then to oranges. The powerbands and efficiency ratings are going to be all over the place. They all have different power curves. IE: Roots or twin screw, Turbocharger, and Centrifugal supercharger. All work within different power bands(RPM range) and different efficiency ratings. And all have a specific purpose
The problem is we are trying to compare apples to lemons and then to oranges. The powerbands and efficiency ratings are going to be all over the place. They all have different power curves. IE: Roots or twin screw, Turbocharger, and Centrifugal supercharger. All work within different power bands(RPM range) and different efficiency ratings.
The only way I'd ever consider a supercharger on a diesel is if it were of a centrifugal design. Something like a Pro-Charger in the F1 line-up.
But even then, they are only rated to 38 PSI max boost. And although they flow a ton of CFM, enough for over 1500 HP, we don't turn a high enough RPM to take advantage of a high volume low pressure induction system. You'd be better off compounding a big turbo with a supercharger if you were looking for off idle response from the supercharger, and high boost from the turbo.
I would want a twin screw compressor like a whipple. The twin screw is the most efficient compressor on the market. Also with something like the pro-charger you would not be able to get as much boost at idle & the really low RPMs that you would be able to with the twin screw or roots type.
oh hey if the prochargers can make 38 thats all the big turbo needs to make in a mild twin setup anyway right so what if you had a procharger feeding in to a roots style and have instant full boost at 1500rpm you could break all kind of stuff
I think you'd lose quite a bit of fuel efficiency by running a supercharger vs. a turbo. Turbos use some of the unused heat spit out by the engine and convert it back to air pressure to increase efficiency through the engine. A supercharger just uses power straight off of the belt system. Basically a general engine has 33% efficiency. In other words, 33% of your power goes out in exhaust heat, 33% goes into the radiator as coolant heat, and 33% goes to the crankshaft. The reason that turbo diesels are so efficient is because part of that 33% in the exhaust gets re-run through the engine through the turbo. Another thing to think of is that boost pressure is directly proportional to engine RPM. You only make boost pressure when your air inflow outpaces the speed at which your engine can take it in. In a supercharger (with the right pulleys) you should make a constant boost I would think, because your engine speed designates your compressor speed. Any CFM that your super produces would be consumed immediately through the engine.
It would act like a supercharger when you need it, but it would capture braking energy instead of losing all that heat into your brakes.
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