Anthracite SC

We had this discussion a LONG time ago, and I can't find it in the archives, and since it's basically a new generation of members here, I thought it would be cool to start a new discussion about it.

Turbocharging vs Supercharging?

what's better?

I've heard conflicting points on both sides.
Some people say supercharging is better for low end and turbocharging is better for top end.

That's a very basic statement.

Can any more experienced owners or operators of supercharged or turbocharged cars come into this discussion and help me understand the pros and cons of each again?

thanks.

awj

It's up to the parts available, cost, and application. IMO

A supercharger works driven by pulley from the serpentine belt.
Pros:
Up boost by reducing the size of pulley.
Boost at low rpm.
Nice whining sound.
Probably a little cheaper.

Cons:
The pulley can only get so small. Not as much boost potential.
Parasitic drag. It takes power to make power.

Turbo is driven by exhaust gas.
Pros:
More boost potential.
nice whine
More sounds -

Cons:
Turbo lag - it takes time for the exhaust gasses to get the turbo spooling
More maintenance and additional equipment required.
More expensive.

I'm looking at F-max, Toyomoto, or a piece together set-up.
f-max around 5,000$
toyomoto 6-7,000$
piece together - don't know yet, need to do more digging.

No turbo yet, just thought I'd chime in because I'm bored.

Anthracite SC

Thanks for the pros and cons..but which one is better for ultimate performance?

awj

It's too hard to say for sure. You can get stellar performance out of either with enough money and know how on your side. To be hard pressed, I'd say turbo. But on the SC400 a supercharger may be a better way to go.

Lex Luthor

This could be a looong response, but we can boil it down to a couple of categories. Efficiency (of the unit itself, plus volumetrically and thermodynamically), cost, power production potential, spool-up time, ease of installation, and availability.

Efficiency - Generally speaking, a turbocharger blows away a supercharger here, the beauty of a turbo is that the compressor is driven by the wasted thermal, sonic, and kinetic energy of the hot, expanding exhaust stream. This is really one of the best features of a turbo, and wins half of the argument for me. A supercharger's compressor is driven off of the engine's crankshaft, creating a significant parasitic loss just to drive the unit. For example, a 4cyl with a blower running 6-10psi will lose anywhere from 12-20hp just to drive the unit at the boost level. On the other end of the spectrum, a Top Fuel car eats up about 700hp just to drive that huge roots blower.

Cost - Both are in the same ballpark

Power - A turbocharger hands down has more ultimate power potential than a supercharger

Spool Up Time - contrary to popular belief, a properly sized, smaller turbo can be made to spool just as fast as a blower, without getting into housings, wheels, AR, etc, but this smaller turbo will obviously be more limited in how much it can flow and therefore, how much maximum hp it can produce. The fact that a blower is driven directly off the crank is what gives it that quick spooling and that nice, linear power delivery.

Ease of Install - Since a supercharger requires less plumbing, and in some cases no external oil feed, it is generally easier to install.

Availability - both are readily available, but some turbos are definitely hard to get a hold of, but there's so many choices out there, that it's all good

VERDICT - for mild street applications, for a bolt-on and go with a 30-40% increase in hp, the supercharger wins (centrifugal that is, though a roots blower does have a nice linear power delivery). For anything serious, where you know that in a year she'll feel slow again, turbo is for you. I tried to keep it short, but nothing's that simple, depends on what you're looking for.

healerhand

One word:

Hardcore, Horsepower Junky, race intention = Turbo
Daily Driver, Race once a while, low maintiance =supercharger

SupraCoup3

that was more than one word

awj

Hell yea - turbo me baby. Good info Lex.

SC300TURBO

iTrader: (2)

i dissagree.......there is no additional maintainence for a turbo besides using mobil 1 synthetic and just good basic upkeep on the car..and for daily driving its great ...if you want to dive the car like normal you keep it at low rpms...when you wanna fly you keep the rpms up...no one races at low rpms....and with a proper sized turbo you can have spool up in the 2000 rpm range.....also a roots type charger has no lag.....but a centrifigal charger does have lag........so there for no better than a charger at all........and as far as boost adjustability...turbo you pusha button or twist a **** on the fly...//.....or even have a boost controller that controls boost by specific rpm and gear....while on an s/c you have to change belts and pulleys.....
a turbo is alot more functional...makes more power......totaly adjustable on the fly.....and kicks s/c *** but htats just my opinon...and a very stong one at that with eveidence to back it....Jeff

JAC JZS

I agree my TT has almost no turbo lag whatsoever. Also sequential setups are the best for reducing turbo lag and still produce very good hp.

abutler696

JAC JZS........are you the same guy on supraforums with the ebay auction for your supra who I've been talking to with the 94 auto tt?

lex400sc

A sequential intercoolled twin turbo can defeat all the turbochargers faults. Plus the blow off sound is music to my ears.

I would only use a supercharger when an engine benefits more from it than it would a turbo. IE: 4.6L Ford engine.

Now this is a TURBO!............

Lex Luthor

Looks like an SP63.

wwest

Both are compromises.

The old saw about the turbo boost being "free" simply doesn't hold water. If you want to PUMP a specific volume of air up to a certain pressure level that will take a finite level of energy, WORK!

Most turbos will not come on-line until the exhaust gas volume/pressure is sufficient, enough "waste" HP, to do the work of compressing the incoming airflow. And on the high end many, if not most, turbos have a pressure bypass so as not to overboost the engine, more "wasted" energy.

The main problem with SCs lies in the very same area. SCs can be "geared" to provide sufficient boost pressure even at idle, but unless it has a clutch that pressure must be bypassed after doing the work of pumping it, not very efficient.

Secondarily if the SC is so geared then by the time the engine speed is mid-range and beyond tremendous amounts of pressurized airflow is being bypassed, DUMPED!

The best of ALL worlds would be a variable speed constant dispalcement SC driven by a hydraulic servo motor with the hydraulic pressure/flow supplied by the power steering pump and metered by an electronic servo valve so the SC rotation rate always exactly matches the engine's need for pressurized airflow throughout its RPM range.

One of the diesel engine manufacturers has now done exactly that.

Since there is no way a turbo can be brought on-line quickly at the low end an SC is obviously the best solution if its output can be somehow modulated to match the engine's airflow needs as dictated by the position of your throttle foot, of course.

wwest

Oh, almost forgot.

Guess what your power steering pump is doing when you're driving straight ahead at 60 MPH?

Pumping the power steering, hydraulic, fluid up to 3000 PSI just so it can be immediately by-passed right back into the sump/reservoir.

Power steering pumps much have enough low speed pumping capacity to provide 3000 PSi of volume even at idle when you're manuvering into a parking space. Can you imagine how much energy is being bypassed, wasted, at 60 MPH, 3500 RPM?