Are Kompressors engaged full time?

[Baron_Samedi]

Just wondering if pootling around (wafting as it were) would cause the Kompressor to spin?

 

[Will]

I think it depends on the car/year.

Early Kompressor engined models had an electromagentic clutch that would engage the compressor somewhere around 1500RPM (?) from memory. The later models have the Kompressor engaged all the time - even at tickover.

Will

 

[Baron_Samedi]

Nice info Will.

Soo, pussy footing around the place may not save me that much juice

 

[Will]

Pretty much, it'll be running as soon as you're moving anyway.

I wouldn't worry about it

Will

 

[Baron_Samedi]

Nahhh, I like the sound of the Kompressor too much

 

[stats007]

Even if the supercharger is running there will be a bypass valve at low speeds.

 

[Baron_Samedi]

Complications complications

What does the bypass valve do?

 

[Dryce]

I think it depends on the car/year.

Early Kompressor engined models had an electromagentic clutch that would engage the compressor somewhere around 1500RPM (?) from memory.

I thought they were all still clutched. You potentially lose out on economy if you leave the supercharger engaged all the time.

The actual engagement of the supercharger on the R170 230K seems to be based on demand. AFAICT it only seems to be noticeably active above 2500 to 3000 RPM when you're heavy footed.

 

[stats007]

The clue is in the title .

 

[Smatt]

(As per stats007)
By definition, I thought a Kompressor was engaged full time, otherwise surely it would be named a turbo.

 

[rf065]

(As per stats007)
By definition, I thought a Kompressor was engaged full time, otherwise surely it would be named a turbo.

A turbo is driven by exhaust gas, a supercharger is mechanically driven by the engine.

Russ

 

[Will]

I thought they were all still clutched. You potentially lose out on economy if you leave the supercharger engaged all the time.

The actual engagement of the supercharger on the R170 230K seems to be based on demand. AFAICT it only seems to be noticeably active above 2500 to 3000 RPM when you're heavy footed.

I used to - but it's not the case.

I used to have a '97 W202 C230 Kompressor which had the clutch (as did many others), but a friends '01 CLK230 Kompressor doesn't, it runs at idle.

Can't say for other models such as the AMGs or the newer 1800cc W203s etc though.

Will

 

[Smatt]

A turbo is driven by exhaust gas, a supercharger is mechanically driven by the engine.

Russ

Yes

 

[Bobby Dazzler]

Apparently the SC engages at 2800rpm on my car, so I try to stay below 2500rpm when I'm feeling particularly environmentally aware - or tight.

 

[Baron_Samedi]

Honesty,

I like that....

I'm going to have to do some research on the M271 engine I think....

 

[Adam230K]

My engine the M111 has an electromagnetic clutch as Will said, which engages at 1500rpm, and i've felt this for myself.
Every single kompressor engine made after that (even the AMG's i believe) have their kompressors working constantly. The bypass valve is self explanatory (i think), it just releases the excess air at low rpm when its not needed.

 

[Nibbo]

I am confused (I know doesn't take much!).

I thought that a supercharger, much like a turbo, simply increased air flow so instead of the engine having to suck air in it was forced in by the impellers.
If this is the case, why would avoiding using it help fuel economy?

 

[kwakdonut]

I am confused (I know doesn't take much!).

I thought that a supercharger, much like a turbo, simply increased air flow so instead of the engine having to suck air in it was forced in by the impellers.
If this is the case, why would avoiding using it help fuel economy?

A supercharger is driven by the engine, a turbo by the exhaust gasses.

Therefore, a supercharger will work from idle up but this will probably be too much boost and thus, air is bled off.

 

[stats007]

More air requires more fuel...

 

[Baron_Samedi]

Thanks for stopping in stats007!

From my limited research I think you are correct (FWIW) and the clutch does come in at 1500rpm to give the lower powered cars a bit of punch.