Too much torque!!

[R2D2]

For those of you of a mathematical bent; I have often wondered why my car is as fast as it is and why it uses fuel as it does. Let's see if anyone else can do the maths and then better still explain why!? My engine is a 1.8 kompressor M271 204046 143bhp in standard spec... you can research the torque bit!
Dyno graph below.

 

[Mike Walker]

Right - working on it now.......

 

[Bellow]

I'm confused! I thought a 1.8 kompressor M271 was a petrol engine but the dyno plot is surely of a turbocharged Diesel?
And why the slump in torque at 1800rpm?

 

[R2D2]

I'm confused! I thought a 1.8 kompressor M271 was a petrol engine but the dyno plot is surely of a turbocharged Diesel?
And why the slump in torque at 1800rpm?

It is a Supercharged Petrol engine...

 

[R2D2]

Just realised Mark (Mark300SL) would have sorted this puzzle out in no time

 

[Bellow]

It is a Supercharged Petrol engine...

That peaks at 3600 rpm??? Not since the 1920s...

 

[kth286]

For those of you of a mathematical bent; I have often wondered why my car is as fast as it is and why it uses fuel as it does. Let's see if anyone else can do the maths and then better still explain why!? My engine is a 1.8 kompressor M271 204046 143bhp in standard spec... you can research the torque bit!
Dyno graph below.

What road speed is the car doing at approx 2400 revs in top gear ?

 

[R2D2]

What road speed is the car doing at approx 2400 revs in top gear ?

Do you want an accurate answer to that ie. a test run. a guessimate would be 60mph hth.

 

[Bellow]

Unless I am missing something glaringly obvious, then either the quoted rpm is not the flywheel rpm, or that is a plot of a turbocharged Diesel.

 

[R2D2]

Unless I am missing something glaringly obvious, then either the quoted rpm is not the flywheel rpm, or that is a plot of a turbocharged Diesel.

All I can tell you is that it is my 1.8 Kompressor on a dyno....

PS. Ignore the 1600rpm reading and base the calculations on the 3600 rpm on the graph that is more reliable(?)

 

[markmifsud]

why would they show max power at 3600 rpm ?

 

[R2D2]

According to the MB literature my engine is supposed to develop 220nm of torque between 2500-4200 revs. Max power of 143bhp is supposed to be at 5200rpm. The same engine in a c200 produces 240nm between 3000-4000 and a c230 produces 245nm between 2900-5500rpm....

 

[Mike Walker]

right - all clear to me now.....

 

[Bellow]

All I can tell you is that it is my 1.8 Kompressor on a dyno....

And the question is 'why does my car make nearly double the torque it should?'?

No car just doubled its torque output on its own. Not ever!

My strongest suspicion is you have been given the wrong dyno plot. Nothing adds up. There is no other explanation. Phone them - now!

 

[Bellow]

right - all clear to me now.....

Please enlighten us. Please, please, please,please,please,please,!!!!!

 

[camerafodder]

That graph is very wrong.

 

[R2D2]

For what it's worth I was there when the graph was plotted and believe it to be correct. Remember it is an automatic as well and the bhp figures are just slighty up ie 149bhp instead of 143bhp...

 

[camerafodder]

For the sake of argument, lets say then that you've got 300lbFt of torque at 3600rpm. That equates to over 200hp.

 

[flango]

That is definitely not a dyno chart of a petrol car, you only have to look at the torque to figure that one out.

Something not right, as previously posted OP given the wrong printout?

 

[R2D2]

For the sake of argument, lets say then that you've got 300lbFt of torque at 3600rpm. That equates to over 200hp.

but it would explain how I held off a Mondeo 220 diesel and also my fuel consumption and also my long held belief that my car is quicker than it should be. The C230 kompressor M271 is the same engine.....