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Turbo or Supercharger?

  • Turbo!!

    Votes: 26 37.7%
  • Supercharger!!

    Votes: 43 62.3%

Age old question. Turbo Vs. Supercharger

11K views 78 replies 33 participants last post by  bet on black 
#1 ·
So.... What do you guys think? Do you like a turbo(or two, or 8..) or a supercharger?

We'll make this general and say on a sbc, but the application really doesnt make much diff.... lol

Im highly partial to a turbo because I've been around them and know a bit about them and how to make power from them..

Plus I love the sound...

Ok, pro's and cons to both sides...

Pro turbo,
No loss of power due to belt, (runs off exhaust pressure)
can produce a ton of Psi
efficient design
Better gas milage than supercharger
Great sound

Cons of turbo
Obvious boost lag (big con for 4 cylanders)
plumbing can be a problem
difficult install
inconsistant boost from turbo sometimes

Pro supercharger
Instant power
easyer install
More readily avalible
Great sound


Cons of supercharger
Belt drag at high end
Not for tight fit engine bays
less fuel efficient


Andrew
 
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#2 ·
gotta go supercharger. IDK which is "BETTER" but on a SBC i think a Supercharger is the way to go. Plus it just looks angry. if ur on the street nothing wants to mess with you. But i like to intemidate so thats just me.
 
#5 ·
Id agree that turbo's are probably more efficiant as far as lighter weight, no big belt to turn and it doesnt take power to make power........But, A turbo in no way matches the looks of a big ole roots blower stickin thru the hood of your car.
So if you want a sleeper then go Turbo, if you want the looks go roots supercharger. HG :thumbup:
 
#11 ·
Personally I'd go with a turbo for my car.. but thats A: because my trani wouldnt do very nicely with a blower, and B: because I love the TQ curve. C: A blower just wouldnt fit...

Besides, Im used to 4 cyanders with turbo's...

Dady's cars are 944 turbo porsche's... 2.5l turbo with 430 hp with the larger turbo
 
#12 ·
Well, my choice is clear enough.......

I just dont understand the whole turbo lag thing. I am running a very large turbo and there is no lag. It has to do with having the proper setup. If you put a huge turbo on a tiny engine there may be some lag, but with the EFI systems available with ALS(antilag system) control it is not really an issue.


Chris
 
#15 ·
Chris, the lag is with the 4 cylander and smaller 6 cylander engine's that rely on the turbo. Large v8's have enough tq to not be able to notice the lag..

Putting a small turbo on a 4 will give less turbo lag, but much less hp... and a large turbo (especially a large hot side of the turbo) will cause more turbo lag Thats what lag Im talking about...



Ya, that was a very inefficient use of turbo's on the 8turbo car.. Each turbo produces what, 2psi? geez...

Andrew
 
#16 ·
I know of people running HX50's on 2.2 liter race cars with little issues of lag. That turbo is large enough for a big V8. The key is what I mentioned before with the ALS. By retarding timing and dumping raw fuel in the exhaust the exhaust heat and pressure can be greatly increased in drag cars. In rally cars a similiar technique is used between shifts to reduce spool time.

Another strategy is to us a hybred turbo with a very small turbine and a large compressor. Then a large wastegate is used to bypass the extra air that would cause the turbine to become a restriction.

As for the 8 turbo engine, the turbos all produce the same boost. Probably around 15 psi considering what they are using.

Chris
 
#19 ·
No, turbos do not use power to make power. They use spent heat energy in the exhaust to drive a turbine instead of just letting the heat out of the exhaust. While there is some pumping loss on the engine it is minimal if the turbine is properly sized. Do some reading on thermodynamics.......

Chris
 
#20 ·
I went supercharger. In the forced induction world, what's cooler than a big blower? Mad Max would probably never made a dime if that car had a turbo under the hood.....


Also, just b/c you have a supercharged engine doens't mean you have to chop a huge hole in the hood - look at the new Buick Ultra's, it's a supercharged grandpa ride. (which is only a change of pulleys away from making a nice sleeper...)
 
#21 · (Edited)
TurboS10 said:
No, turbos do not use power to make power. They use spent heat energy in the exhaust to drive a turbine instead of just letting the heat out of the exhaust. While there is some pumping loss on the engine it is minimal if the turbine is properly sized. Do some reading on thermodynamics.......

Chris

Chris, not saying you're wrong because I know that you know what you're doing, I just need a bit of clarification on something.

I was under the impression that turbos work on the 'flow' of exhaust gasses to 'rotate' the turbine, not just the presence of heat. This is where the pumping loss comes from because a normally free-flowing exhaust is now restricted and disrupted by a turbine.

Just want to be sure that this is correct, because this information leads me to understand what happens when 'lag' occurs. It's when the engine is revved and has to wait to produce the 'flow' of exhaust to be able to turn the turbine to produce boost to feed back to the intake to increase performance. The fact that the turbo depends on exhaust causes lag, not heat.

I'm not 'saying' this is what really happens, and I'm not 'saying' I'm right and you're wrong. I'm saying this is the first time I've heard something other than what I was told and understand to be true by someone ('you') who is probably more credible than whoever I heard it from. In fact, I'm asking you because I really don't know anyone else who know's their sh!t like you do when it comes to turbos. hehehehe.

I'm waiting for a response before I vote because this is pretty much the biggest determining factor for me.




RESPECTIVELY CONFUSED :thumbup: :confused:


MoocH
 
#22 ·
I am not thermo guru by any stretch of the imagination.

The best way that I can explain it is that there is a certain amount of energy that is needed to drive the turbine fast enough to make boost. That energy is extracted from the exhaust gas. This energy is in the form of heat and pressure and is expressed as enthalpy(I think), or total energy of the media.

The In an NA application exhaust pressure is minimized to increase flow and decrease the pumping loss to the engine that is needed to expell the exhaust gas. In a turbo engine the exhaust gas is restricted to increase velocity pressure and temperature. This causes a build up of energy before the turbine. As the gas travels through the turbine to reach the lower pressure/lower heat side of the turbine it gives up a portion of the energy to turn the turbine.

When I say that there are pumping losses this is where this comes in. Basically a turbo engine sees about the same power loss as any engine would see with a restrictive exhaust system. I guess you could say that it robs power from the engine, but it is different from a belt/gear driven blower that automatically takes ~10% of the power generated to turn it.......in my mind at least.

Maybe I am just dead wrong.....like I say, I am no expert.

Chris
 
#23 ·
Although turbo's do create some restriction in the exhaust which does take power it is no where near the power waisted drawing energy directly off the crank in a supercharged application. I used to vote for s/c but the more I learn about turbo's the more I become convinced that they are Superior
 
#24 · (Edited)
TurboS10 said:
No, turbos do not use power to make power. They use spent heat energy in the exhaust to drive a turbine instead of just letting the heat out of the exhaust. While there is some pumping loss on the engine it is minimal if the turbine is properly sized. Do some reading on thermodynamics.......

Chris
actually they cost the engine some HP as with superchargers.

The reason?

They create back pressure in the exhaust runners and headers and force the engine to work harder everytime those exhaust valves are opened. They cause more heat and restrict the exhaust flow leaving the car almost totaly useless under 3000 RPM, or when there is no boost(or too little) to compensate for the extra work the engine has to do.

Basicly, when the exhaust valve opens, that exhaust gas in the exhaust system before the turbo pushes against the gas trying to get out of the engine making the engine lose a bit of power first, and then as the piston is still rising the engine now has to force that gas through a small turbine thats causing the restriction and hampering performance. Yes turbos might use less power to make power, but they still USE power.

There is no "free" power added out there, that is nothing that can make power without taking it first. Well... you can count NO2, but the cost of that is in engine wear.

And turbos do not "use" heat, they help create it by restriction and pressure of the exhaust gasses. Heat is a turbos enemy as with any engine part. Back pressure is a turbos friend. I know enough on "thermodynamics" thank you.
 
#26 ·
87442lover said:
actually they cost the engine some HP as with superchargers.

The reason?

They create back pressure in the exhaust runners and headers and force the engine to work harder everytime those exhaust valves are opened. They cause more heat and restrict the exhaust flow leaving the car almost totaly useless under 3000 RPM, or when there is no boost(or too little) to compensate for the extra work the engine has to do.
NO! A properly built turbo exhaust is designed to maximize velocity by using slightly smaller pipe than would be used on an NA engine of the same power output. When the engine is not making boost in the low RPM the increased velocity is a good thing. If there is not enough flow to cause pressure ot build in the exhaust then the system is not robbing any power to speak of.

87442lover said:


And turbos do not "use" heat, they help create it by restriction and pressure of the exhaust gasses. Heat is a turbos enemy as with any engine part. Back pressure is a turbos friend. I know enough on "thermodynamics" thank you.
And wrong again.

Perhaps you can explain why EGT will drop ~200 oF as it passes through the turbine housing. The turbine does use heat or more specifically heat transfer. Heat is energy and the turbine extracts energy from the exhaust gas to do work.

Do some reading on ALS and you will find proof of this. By using electronic control of fuel and timing, exhaust heat can be increased at a give RPM to spool the turbo. It is used on rally cars between shifts and on drag cars to spool the turbo on the line when the engine is not loaded and not moving much air. This works because the added heat increases the energy in the exhaust available to do work.

Chris
 
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