Superchargers, Turbochargers, and Performance

[Power Hungry]

So I found this conversation on FB and thought it brought up some good points.

https://www.facebook.com/charlie.fis...58937041470148

It is an interesting discussion between blowers and turbos, and had quite a few good points. I have a number of thoughts on the subject and would very much like to continue the discussion here, if anyone is interested.

[Jackpine]

I'd be interested too, and have to admit I don't really know the difference between superchargers and turbos, so I'll look that up in a moment.

I DO know that what counts is the actual mass of air that is delivered to the engine - more air mass means more fuel can be added and that equates to more power. Heating air reduces it's mass/volume, so a cool supply is good. Pressurizing air tends to heat it, but you can't increase mass without also increasing pressure. If a turbo can increase the mass more than a supercharger, or, if the turbo takes less engine power to deliver identical mass than a supercharger, then the turbo will win.

So, that's my rather "obvious" input for now. My deck installers have just arrived, so I have to leave.

Edit: OK, I've now done a bit of research and found that I DID sort of understand the difference between a turbo and a supercharger. I learned though, that a supercharger doesn't have the lag that a turbocharger has since the supercharger is driven directly by the engine. I can see why one is preferable to the other depending on the use. I can't help but think, though, that with proper engineering, you could get equivalent power from either device.


- Jack

[Longshot270]

Without doing any research or phoning a friend that races mustangs.
WAG 1-turbo is scavenging energy that is not very useful while blower is running a belt, gear set and compressor directly on the engine.
WAG 2- turbo intercooler dropping that temp a bit? Do they put intercoolers on blowers?

A little bit of both?

Or, just like a kid in the back seat making a long drive feel longer, blowers just whine more and that's a drag on everyone.

[ticopowell]

From what I've looked at you guys have the basic understanding.
I did hours/days/weeks of research on turbos and superchargers so I think I have a decent understanding of the differences and benefits.

Turbo, uses exhaust gas to spin a compressor blade to increase the quantity of the air entering an engine.
Pros:
scavenges "free" energy from the exhaust
can have fairly simple plumbing
sounds cool when the blow-off valve goes psssssssssst
popular with manufacturers, so they are easy to find and fix
"efficient"... aka Eco boost.

Cons:
Heat (most do have an intercooler, especially stock ones in a factory car)
varied power output
"lag"



Supercharger, uses a belt from the engine's crank shaft to spin a "blower" of some sort, can have multiple styles, most common are roots and one that looks like a turbo with a belt attachment.
Pros:
power is stable, 1500rpm always makes the same power (assuming the blow-off valve hasn't reduced the pressure)
more low end power, aka torque

Cons:
can have complicated plumbing, wiring, belt routing, etc...
Heat (Most have an intercooler, either pumping coolant between the blower and the intake, or routing it up front like a turbo)
Takes engine power to run, don't quote me but Ive heard a 500rwhp car with a supercharger is making 600+ at the engine, but uses 100+hp just to run the blower.


Personally I prefer a supercharger. I used to have good reasons but I've forgotten those hahahaha. If I am going to drag race the supercharger makes sense because of the low end power and the predictability. I am not saying they don't exist, but I don't ever remember ever seeing a top fuel dragster with a turbo, just superchargers. The quicker you get to speed the faster you will cover the 1/4 mile (or 1000', or 1/8 mile, etc...).

My truck has 2 turbos, and i don't really like the power delivery, but that's partially because it can't decide which of the 10 gears to use. It definitely has a whistle under load, so that's fun to listen to, but it's so quiet I doubt my wife even hears it.

I also assume Diesel trucks (and gas ones too) have turbos because of the simplicity of the plumbing and the potential reliability improvement. If a supercharger is taking up 100+hp then you are stressing the engine that much more, and it's better for the bean counters at ford if the warranty claims are fewer because they used a turbo vs a supercharger. Most cars/trucks with superchargers (hellcats and shelbys come to mind) are built for specific things like racing. Otherwise they seem to favor turbos.

That's all I got for now. What do you guys think?

[Longshot270]

I did get to drive an ecoboost expedition from San Antonio to Corpus Christi and back one weekend to help following a backflow incident. I don't remember what the mileage was but it was better than my jeep at the time. The motor had good pep, the whistle was fun and I spent all my city driving with the radio off to listen. The passenger I had couldn't hear it and was irritated by the lack of music. Lol