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  #16  
Old 03-19-2006, 08:09 AM
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Quote:
Originally Posted by Ricochet
I was misinformed. They have two intake pipes going up and meeting eachother at the same throttle body. For a turbo, rip out both those stupid plastic pipes and just make one steel pipe going from the turbo to the intake.

Ok cool so it still has dual intakes right?
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  #17  
Old 03-19-2006, 06:41 PM
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Dual intake pipes, yes.. but only one intake. They love to overcomplicate things like here where they added a second pipe. I drew a picture to hopefully clear it up for you.

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  #18  
Old 03-19-2006, 07:11 PM
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ohhh ok gotcha. Thanks for the drawing....i would have known if i had removed his plastic shield on top of the engine. That damn thing there confused the hell out of me since i saw two pipes.
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  #19  
Old 03-19-2006, 07:22 PM
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How can you not know the difference between a turbo and a Super charger?
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  #20  
Old 03-19-2006, 11:21 PM
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Quote:
Originally Posted by spinn360
How can you not know the difference between a turbo and a Super charger?

because he is teh King of teh N00bs!

also....

Quote:
Originally Posted by SilverSpear
Needs turbo maintenance each 30K miles (I think)
nope - no scheduled maintenance for the turbo. many '02 WRX's running around with higher than stock boost with 100,000+ miles on stock turbo.

Quote:
Originally Posted by Ricochet
On a V6 yes you can go twin turbo, but each turbo would have to be small because each one is only feeding 3 cylinders. You could also have one huge turbo to feed all 6 though. There would be some lag, but at mid/high rpms there would be a lot more power potential where two smaller turbos would reach peak psi earlier.
an alternative twin turbo set up would be to operate sequentially - a small turbo to provide quick, no-lag boost, and a larger turbo that joins in at higher rpms and makes big power. you don't see these setups very much anymore because they are pretty complicated. i believe the JDM Legacy RSK's and Toyota Supra MKIV's twin turbo systems worked this way, among others.
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  #21  
Old 03-19-2006, 11:57 PM
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Yeah that would be setup like the single turbo design, both being on the pipe where all 6 exhaust pipes meet. Not worth it unless you have a bajillion dollars burning a hole in your pocket.
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  #22  
Old 03-20-2006, 05:43 PM
oab_au oab_au is offline
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Quote:
Originally Posted by SilverSpear
But there is a concept between the two that I am not getting straight. You all know that when the A/C pump is ON, you feel the engine less responsive, like if you are pushing gas while overloading the car with 4 passengers. When you turn the A/C OFF, the car is in "relief" with better responsiveness. This happens because the A/C pump is activated with the engine rotation power. The supercharger uses the same concept, it takes power from the engine through the belt but on the other hand it pumps air back into the engine, hence providing power. But still the engine is stressed from that additional pump he has to activate even though it is providing more compression.

As for the Turbo, it is getting its power from the exhaust, so there is no stress on the engine except for that additional compression that the turbo is providing over the pistons.

Is my statement about the Supercharger above, correct? Then the engine will be "USED" more than the turbo engine.

And what are the Pros and Cons of each one? Let me be the first to state them:

Supercharger:
Pros: No lag at low rpms, and quick responsiveness.
Does not need continuous maintenance as the turbo does

Cons: higher fuel consumption from being continuously turned on with the engine
Power vanishes at high rpms.
Consumes engine life more than a turbo engine.
Belt driven, so it is gaining power and loosing power also in the same time.

Turbo:
Pros: Lower fuel consumption than the supercharger.
Power increase at high rpms.
Consumes engine life less than the supercharger.
Gains power from exhaust gas and not directly from the engine, hence the engine is gaining without a loss.

Cons: no power at low rpms, in other words, a lag.
Needs turbo maintenance each 30K miles (I think)
The supercharger takes power from the engine when pumping boost. When cruising the blower is spinning in a partial vacuum, so it consumes very little power. In fact I have had blower belts break, due to a backfire, and the blower just kept spinning, due to the engine pulling air through it.

The fuel consumption is the same for both, as long as they are driven the same.

Quote
"Gains power from exhaust gas and not directly from the engine, hence the engine is gaining without a loss." Quote.

The old saying " you get nothing for nothing". The turbo does consume power from the engine. To fit the turbo, the existing exhaust system has to be removed and replaced with a short system to power the turbo. So the power that the factory exhaust provided is now lost. The low speed Inertia is not there, or the high speed resonate system is not there. So this must be considered as power taken to drive the turbo.

The other differences are the supercharger has a cooler air output than the turbo, that suffers from heat transference from the turbine side to the compressor side.

The supercharger provides boost at low rpms, but is inefficient above 1.5 atmos boost. The turbo provides little boost below 2500/3000, but can produce boosts in excess of 1.5 atmos.

Harvey.
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  #23  
Old 03-20-2006, 07:51 PM
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Quote:
Originally Posted by oab_au
The supercharger takes power from the engine when pumping boost. When cruising the blower is spinning in a partial vacuum, so it consumes very little power. In fact I have had blower belts break, due to a backfire, and the blower just kept spinning, due to the engine pulling air through it.

The fuel consumption is the same for both, as long as they are driven the same.

Quote
"Gains power from exhaust gas and not directly from the engine, hence the engine is gaining without a loss." Quote.

The old saying " you get nothing for nothing". The turbo does consume power from the engine. To fit the turbo, the existing exhaust system has to be removed and replaced with a short system to power the turbo. So the power that the factory exhaust provided is now lost. The low speed Inertia is not there, or the high speed resonate system is not there. So this must be considered as power taken to drive the turbo.

The other differences are the supercharger has a cooler air output than the turbo, that suffers from heat transference from the turbine side to the compressor side.

The supercharger provides boost at low rpms, but is inefficient above 1.5 atmos boost. The turbo provides little boost below 2500/3000, but can produce boosts in excess of 1.5 atmos.

Harvey.

We have all been schooled by Harvey.....I feel so blessed
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  #24  
Old 03-21-2006, 10:08 AM
hayasa hayasa is offline
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Just to throw in a few of my comments in the debate, coming from an STi with tuning and lots of time to mess around with engines.

1. Check out the "how things work" web site (http://auto.howstuffworks.com/supercharger.htm and http://auto.howstuffworks.com/turbo.htm) for info on turbos and superchargers, but the info is a bit dated. There are lots of books out there, too, for the truly interested. I've collected most of the more popular ones, so I can give you thumbs up or down before you buy. First lesson - a turbo is a type of supercharger. The complete term is a "Turbo-supercharger." However, I like lots of folks use the term "supercharger" (sc) to mean a non-exhaust driven forced induction system.

2. Keep in mind that there are two types of (non-turbo) superchargers, centrifugal and positive displacement-type (roots, screw, etc.) They are different in applications, and some of what was mentioned earlier only applies to one or the other.

3. The biggest differences in output between a turbo and a sc is efficiency. A mild to good turbo will return a 80% return on power increase (100% being double the power of a non-forced induction engine, all things being equal), while even the best supercharger rarely gets over 50%, though this generally applies to positive displacement-type which is the most common on commercial vehicles.

4. Also, the boost curve is very different because the rotation of the supercharger is directly in proportion to the speed of the engine. For instance, a "properly" tuned supercharger will get the most boost at the highest engine rpm, while a turbo can make peak boost long before redline. And yes, turbos lag, but proper tuning and design engineering can minimize the lag.

5. Finally, another difference is cost. Generally, a turbo system with a customized exhaust, tubing, intercooler, and LOTS of install time will far exceed the cost of a simple supercharger. The SVX is a little unique, but on other cars a complete single turbo will cost roughly twice what a supercharger will run when all is said and done...

Last edited by hayasa; 03-21-2006 at 10:18 AM.
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  #25  
Old 03-21-2006, 09:26 PM
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Yes, you can build an engine with dual superchargers. Centrifugal superchargers are basically belt-driven turbochargers.

I've seen a Chevy V-8 set up with a pair centrifugal superchargers. He had port fuel injection and the intake runners were completely seperated for the two banks of the engine with each supercharger independantly feeding it's four cylinders.

This was back in the late '70's or early '80's. Although the plumbing was neat, as far as I can remember the port fuel injection was what intrigued me the most at the time.

All superchargers 'use' a lot more than 5 HP . . . Think of SilverSpear's comment about turning on your AC, multiply that by quite a bit. The difference with a supercharger is that it's making more power than it's using.

Dan

Last edited by intelisevil; 03-21-2006 at 09:34 PM.
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  #26  
Old 03-22-2006, 12:01 AM
dmnknightomega6 dmnknightomega6 is offline
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Cool

After all This Tech Info. You Might look into turbo lag and misfiring turbos. Just to complete it. Might as well
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  #27  
Old 03-22-2006, 12:18 AM
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Quote:
Originally Posted by n00b on demand
We have all been schooled by Harvey.....I feel so blessed
Well he is our technical SENSEI
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