Superchargers Vs Turbochargers

[Slim Mat]

Just thought I'd start a big interesting topic.

So what is it people.....Superchargers or TURBOCHARGERS?!

Tell us why!

I myself am a turbo man, hence the R32 GT-R. They make more sence!

[ztuned]

hmm good question on a skyline forum

[sh@un]

depends what style of driving you like

but pound for pound, turbos will always make more power- just look at horsepower heroes

[Slim Mat]

Man, wish I could go the Show 'n' Shine, wrong side of the country.

[Cubes]

Why not a bit of both?

Ignore the 'speco' boost guage. lol It was running 9pounds. Oh and the feet. lmao

RB30/25

<-- Gotta love the sound

[Slim Mat]

Man, that VL goes HARD!

Superchargers don't sound as good as turbos.

[Omurru]

it's like asking whats better a holden or a ford, or an rb26 or a 2jz, maccas or KFC? Everyone is gonna have different answers and reasons. Really when it comes down to it, it's what do YOU want?

[700HP-GTR33]

Super Charging.......used on cars today..NEW...give that extra 10% to 20% gain in performance without having to

drop compression that low.

Turbo Charging on the other hand....used on new cars will give to 30% more gain.

These figures all depend on size of motor,type of car and design of motor(low/high comp)

Super Charging also does not involve Inter-coolers...boost controllers...etc etc..this is why Mercedes Benz

use then on nearly anything they want to add a bit of spice too.

[Slim Mat]

Super Charging.......used on cars today..NEW...give that extra 10% to 20% gain in performance without having to

drop compression that low.

Turbo Charging on the other hand....used on new cars will give to 30% more gain.

These figures all depend on size of motor,type of car and design of motor(low/high comp)

Super Charging also does not involve Inter-coolers...boost controllers...etc etc..this is why Mercedes Benz

use then on nearly anything they want to add a bit of spice too.

Everything except the CLK-550, Ga-gish! Twin turbo V8, say over 500hp, woop! Jeremy Clarkson reckons it goes like stink. Top Gear FTW!

[Marco-R34GTT]

However superchargers aren't exactly just superchargers...

There is roots, positive displacement, centrifugal..... I myself am a fan of centrifugal supercharging, 0% lag and as RPM climes, so does boost.... I hate nothing more than blokes in V8's boasting that they've got 1000 pounds of torque thanks to 100 PSI of instant boost at 100 rpm! Never had so much off-the-line get up and go! Well when the rubber doesn't blow....

[R31Nismoid]

Take your beastmaster away...no relevance here

Anyhow... Turbos will be the better option for the RB series, considering (in turbo form) thats what they are equipped with.

Then again... It also depends on what type of supercharger... Be that Centrifugal, Roots or Twin Screw... and then taking into account the purpose of the car

[Forged]

Supercharger or Turbocharger?

I would said neither.

The future is Supercharger + Turbocharger = Ultimate efficiency

Here is why:

Twin-turbocharged FSI engines - Central aspects

Wolfsburg, 29 August 2005 - At the International Motor Show (Cars) in Frankfurt, Volkswagen is presenting to the general public a ground-breaking innovation in the drive sector: The world抯 first twin-turbocharged FSI engine ?the æŸwincharger? The compact 1.4 litre direct-injection engine develops up to 125 kW / 170 PS and has a maximum torque of 240 newton metres in the range from 1750 to 4500 rpm thanks to the combination of an exhaust turbocharger with a mechanically driven compressor.

The 1.4 litre engine delivers a power output of 90 kW / 121 PS per litre, representing a peak value for a series production four-cylinder engine. Furthermore, the æŸwincharger?delivers a torque corresponding to a naturally aspirated engine with a swept volume of approx. 2.3 litres. And its fuel consumption is around 20 percent lower.

THE CONCEPTUAL IDEA

A compact FSI engine with twin, different supercharging as an approach to the solution

The most effective way to reduce consumption is referred to as downsizing. A reduction in cubic capacity and therefore lower friction losses result in a low specific consumption, which equates to better efficiency. However, an engine with a low cubic capacity only meets the current requirements for active road safety and pleasurable driving to a very limited extent. As a result, the objective can only be achieved by supercharging. Classic turbo engines with a small cubic capacity supercharged using exhaust turbochargers have only been used to a very limited extend in the past since they have low moving-off power and are therefore less acceptable. This problem can be solved by a mechanically driven supercharger that supplies additional fresh air to the engine even at low speeds. The challenge was to combine these two systems in a rational way.

The only candidate for injection technology was the FSI technology that is now used by Volkswagen in numerous model ranges. Experience gathered during the last few years by engine developers at Volkswagen in this injection technology had revealed that FSI could be ideally complemented by the two different supercharging techniques, the result being a previously unheard of increase in efficiency.

This gave rise to the world抯 first direct-injection SI engine with twin supercharging for use in high-volume series production ?the æŸwincharger?

THE IMPLEMENTATION

Compressor for power at low speeds, turbocharger for power at high speeds

The choice for the basic power unit was the FSI from the EA 111 engine series as used in the Golf in power levels of 66 kW / 90 PS (1.4-litre) or 85 kW / 115 PS (1.6-litre). The 1.4-litre engine is a four-valve four-cylinder engine with a swept volume of 1390 c.c., a cylinder gap of 82 millimetres and a bore/stroke ratio of 76.5 to 75.6 millimetres. The focus in developing the æŸwincharger?engine was placed on designing a new, highly resilient grey cast iron cylinder crankcase in order to withstand the high pressure of up to 21.7 bar over long periods, a water pump with integrated magnetic clutch and supercharging technology.

However, the injection technology was also modified. A multiple-hole high-pressure injection valve with six fuel outlet elements is used for the first time in the 1.4 l TSI engine. The injector, like that in the naturally aspirated FSI engines, is arranged on the intake side between the intake port and cylinder head seal level. The quantity of fuel to be injected between idling speed and the 90 kW/litre output power requires a wide variability in the fuel flow through the injectors ?given a sufficient mixture preparation time after completion of injection under full-load conditions on the one hand and idling speed with reproducibly low injection volumes on the other hand. The maximum injection pressure was increased to 150 bar in order to achieve this wide range of throughflow. Furthermore, only FSI technology made it possible to achieve a compression ratio of 10:1 which is high for supercharged engines.

The Volkswagen engine developers selected a compressor with a mechanical belt drive in order to increase the torque at low engine speeds. This is a supercharger unit based on the Roots principle. One special feature of the compressor used is its internal step-down ratio on the input end of the synchronisation gear pair.

The exhaust turbocharger also kicks in at higher engine speeds (with wastegate control). The compressor and exhaust turbocharger are connected in series in this case. The compressor is operated by a magnetic clutch integrated in a module inside the water pump. A control flap ensures that the fresh air required for the operating point can get through to the exhaust turbocharger or the compressor. The control flap is open when the exhaust turbocharger is operating alone. In this case, the air follows the normal path as in conventional turbo engines, via the front charge-air cooler and the throttle valve into the induction manifold.

One of the major challenges facing the development was to achieve the best possible interplay between the two superchargers arranged in series. Only when both units ?the compressor and the exhaust turbocharger ?complement one another optimally can the small power unit achieve its required, level torque characteristic over a broad engine speed range in conjunction with a previously unheard of increase in efficiency.

THE RESULT

A twin-turbocharged FSI with two power levels

The ambitious objective of squeezing an output per litre in excess of 90 kW per litre swept volume out of a 1400 c.c. engine could not be achieved with single-stage supercharging alone. However, an upstream compressor enables the boost pressure buildup of the exhaust turbocharger to be significantly increased.

The maximum boost pressure of the æŸwincharger?is approx. 2.5 bar at 1500 rpm, with the exhaust turbocharger and the mechanical supercharger being operated with about the same pressure ratio (approx. 1.53). A straight exhaust turbocharged engine without compressor assistance would only achieve a pressure ratio of about 1.3 bar here. The more rapid response of the exhaust turbocharger enables the compressor to be depressurised earlier by continuous opening of the bypass valve. This means compressor operation is restricted to a narrow map area with predominantly low pressure ratios and, therefore, low power consumption. Consequently, the disadvantage of the mechanical supercharger system in terms of consumption can be limited.

In practice, this means the compressor is only required for generating the required boost pressure in the engine speed range up to 2400 rpm. The exhaust turbocharger is designed for optimum efficiency in the upper power range and provides adequate boost pressure even in the medium speed range. In dynamic driving, this is inadequate for the specified in-gear acceleration values in the low engine speed range. In these driving situations, the compressor is engaged to permit a spontaneous boost pressure buildup. The way in which these two systems complement each other means there is absolutely no turbo lag. The compressor is no longer needed above an engine speed of 3500 rpm at most, as the exhaust turbocharger can definitely provide the necessary boost pressure even dynamically during the transition from coasting to full-load operation.

THE DRIVING EXPERIENCEHigh performance and torque produce low consumption and enormous driving pleasure

The compressor, with its high ratio of 1:5 in relation to the crankshaft, delivers a boost pressure of 1.8 bar even just above idling speed. This provides the power needed when moving off. An electromagnetic clutch integrated in the module of the coolant pump is responsible for switching the compressor on and off. It is driven by an additional belt. A torque of 200 newton metres is available at a speed of only 1250 rpm ?and all the way through to 6000 rpm. In dynamic compressor mode, the automatic boost pressure control decides whether the compressor will be switched on in accordance with the tractive power required, or if the turbocharger alone can generate the necessary boost pressure. The compressor is switched on again if the speed drops to the lower range and then power is demanded again. The turbocharger alone delivers adequate boost pressure above 3500 rpm.

In practice, the ?400 Twincharger?drives like a big naturally aspirated engine with 2.3-litre cubic capacity. This is because the maximum torque of 240 newton meters is available from 1750 rpm to 4500 rpm. The boost pressure gauge installed as standard in the cockpit of the Golf GT 1.4 TSI is the only signal of the furious activity being undertaken by the superchargers and the complex procedure of harmonizing both systems taking place under the engine hood. The driver likes it, because when the needle is fully deflected then the acceleration really presses the occupants back into their sports seats (fitted as standard).

Source:http://www.vwvortex.com/artman/publish/volkswagen_news/printer_146.html

P.S. I remember Toyota had a similar "twin charger" system in one of its production cars in the 90s (can't recall the exact model). Some how the car was discontinued shortly after and the maker ceased further development in the technology all together. Maybe it was due to the lack of "supporting" technologys like Direct Injection (which plays a cruciall role in the formula) at the time.

[Aif]

i have always heard that superchargers are pritty limited, but i havent read into it much?

aif

[R31Nismoid]

Well you should read a lot more.

Search google using the 3 types i listed above and so on.

More than enough info

[Kozeyekan]

Supercharger = no lag but lower top end

Turbocharger = lag increases in proportion to top end.

The nissan march had a supercharger and a turbocharger, with a clutch built in to disengage the supercharger when the turbo spooled up.

Personally, I like turbos. more conservation of energy (by re-using exhaust gasses).

did anyone catch the episode of Top Gear where some mensa woman was doing the "Star in a reasonably priced car" bit and she asked Jeremy what the difference was between a turbo and a supercharger, and he had no idea?

For a guy who gets to drive some beautiful cars, and has done so for decades, he really is clueless.

Still wish I was him though.

i want t veyron.

[scathing]

Super Charging.......used on cars today..NEW...give that extra 10% to 20% gain in performance without having to

drop compression that low.

Turbo Charging on the other hand....used on new cars will give to 30% more gain.

These figures all depend on size of motor,type of car and design of motor(low/high comp)

Super Charging also does not involve Inter-coolers...boost controllers...etc etc..this is why Mercedes Benz

use then on nearly anything they want to add a bit of spice too.

That's because superchargers tend to run a lot lower boost. Hence why they don't need front mount intercoolers (some aftermarket setups may run air to water intercoolers), and why they don't need to lower the compression as much. But wind the boost up on a supercharger, and its going to need intercooling.

Mercedes uses superchargers because they're more drivable. There's zero lag, which for their market (old people who want a cruiser) makes it a perfect fitment. Also because of the target market they don't make high revving screamers, so supercharging is better suited to the type of car they build.

Don't forget that all AMG models are auto - but they don't do it because it performs better or is cheaper to manufacture etc. They do it because their customers don't like changing gears themselves.

And the most powerful Mercedes Benz engines run turbochargers. They're also investigating twin charging, and if I remember correctly they're also working on a tri-turbo diesel (2 small turbos to spool up quickly, and a big single for more top end grunt). Superchargers are slowly being phased out of the Mercedes line-up - their new engines are NA or turbocharged.

[scathing]

I myself am a fan of centrifugal supercharging, 0% lag and as RPM climes, so does boost....

Which makes it inefficient.

You either gear the supercharger to hit peak boost at redline, which means you get no boost down low and a non-linear power delivery, or you gear it to hit peak boost somewhere in the midrange and then need to run a bypass valve to stop it from overboosting....which means a portion of the supercharger's parasitic loss is for no extra airflow and is costing you power you're not making up by introducing a denser air charge.

Since a turbo is already more efficient in terms of parasitic loss compared to a Roots supercharger, that means its far better than a centrifugal one.

I've driven a 350Z that ran a centrifugal supercharger for a while before going to a single turbo. Both made the same peak power, but the turbo felt quicker because there was so much more oomph in the midrange. I would have liked to have seen a boost graph for the pair of them to see when they come on, but I get the feeling the centrifugal supercharger was geared to hit peak boost much higher than the single turbo.

[scathing]

The future is Supercharger + Turbocharger = Ultimate efficiency

Volkswagen has only released a twincharger for a 1.4L engine.

They say its because, as displacement increases, the less efficient this setup becomes. Otherwise I'm sure they would have bolted this onto their 2.0L engine and released an even better GTI....or given the R32 the kind of balls that would make it stupendously fast.

I would love to see a Kei car with a production-spec twincharger setup though. Imagine a Suzuki Cuppucino with one of these, especially in a sports setup? Yum.

[scathing]

did anyone catch the episode of Top Gear where some mensa woman was doing the "Star in a reasonably priced car" bit and she asked Jeremy what the difference was between a turbo and a supercharger, and he had no idea?

For a guy who gets to drive some beautiful cars, and has done so for decades, he really is clueless.

He's always been in the infotainment side of journalism, not the technical side. When you watch / read Top Gear or read his column in the Times, it comes through.

The man talks a lot of crap, basically.

If you want to know how well something works with impirical precision, don't bother listening to him. If you want an opinion of how it goes, which is subjective, then if you find your opinions lining up with him then it'd be good advice.

Personally, I find myself more in line with Hamster's opinions than Clarkson's (and not only because he hates my car).

[paulr33]

each has their place in the car performance world

there is no such thing as " no lag " and " 0 rpm lag" its a load of rubbish

each has lag and takes time before the compressor is efficient