Power, Torque and rolling roads

[fredfloggle]

Two engines may make 125 foot/pounds of torque, but if one is a FixOrRepairDaily turning at 5,000 rpm and another is a Honda turning at 10,000 rpm, the Honda is doing more work than the FixOrRepairDaily, therefore generating more power.

HP = Torque x RPM / 5252

so the FixOrRepairDaily makes 125*5000 / 5252 = 119HP,
but the Honda makes 125*10000 / 5252 = 238HP - must have been an S2000 _

I think it is valuable to point out that rarely does maximum torque occur at maximum RPM - only in the case of race engines where this may be desired .

Therefore it may not be accurate to state that because an engine generates for example 125 ftlbs torque maximum , that we can extrapolate power figures at various RPM's , this can only be done by knowing the torque curve .

The moral of this essay is - it is better to make torque at high RPM for a screamer! - and thats why beause Hondas rev so high they produce the power!

Maybe , however , if the torque curve can be compressed so that it is not necessary to rev to 7500 RPM , then for a road car , this is generally preferable - gear train losses do not increase straight line .

 

[c200Kompressor]

My C200 kompressor as 190.4 CV and 266.5 NM of torque

 

[tuikku]

.
C200cdi, -03

 

[Bobby Dazzler]

Welcome to the forum tuikku!!

250bhp from a C200 CDi - that's a superb improvement over standard - well done!!

I dread to think how much it cost though!!

 

[tuikku]

.
Thanks
I am from Finland.
Most of MB,s here, probably are diesels.

It is an old paper.
I have now little different program.
Power is over 190kw between 4000-4400rpm.
Engine pulls very easily till 5000rpm.


I bought this car as a new, and I have driven now over 170 000km.
Over 100 000km with 170kw, or more.
Car is in “every day use”. I drive a lot.

 

[1998K]

My C200 kompressor as 190.4 CV and 266.5 NM of torque

Your W202 C200K is a 1998cc with similar power and torque of 230K engine, that was a special engine suitable for Italian, Greek and Portugal market, due to tax reason.

I had till 1 and half year ago a C200K sedan, it was my first Mercedes and was the less expensive and more reliable car I'v ever owned

 

[tuikku]

.
Still, same 200cdi

Blue=boost
Red=torque
Black=power

 

[bigyin1]

This isn't really power/torque or rolling road, but a 0-60 testing using a very accurate GPS device, figured it should go in here:

http://farm4.static.flickr.com/3505/3738983186_c28b6ed438_b.jpg

After trying 2-3 times and getting low 13's i tried again with a few revs built up and left foot on the brake and off I went and clocked just under 11.9 which i'm quite happy with. I do have a 0-100 one too (tested on closed roads obviously), have a guess what time that was??

 

[Bobby Dazzler]

I've downloaded Dynolicious to Mrs D's iPhone. Will have a play and share results.

 

[Sp!ke]

This isn't really power/torque or rolling road, but a 0-60 testing using a very accurate GPS device, figured it should go in here:

http://farm4.static.flickr.com/3505/3738983186_c28b6ed438_b.jpg

That graph looks way too linear to me.. I wouldn't put too much trust in those results.

 

[bigyin1]

That graph looks way too linear to me.. I wouldn't put too much trust in those results.

I would, the product i'm using is called a Driftbox and is made by a company that supplies many manufacturers, most car magazines and some forumla 1 teams with their datalogging equipment and are accurate to 0.1mph in driftbox guise, using their more expensive equipment makes it even more accurate. This isn't some gimmic on a phone but a sophisicated piece of timing equipment.

 

[Mark300SL]

Driftbox is a cheaper version of the Racelogic Vbox unit I have used when performance testing for magazines etc. I am sorely tempted to get one for myself as at the moment we only get accurate performance data from Santa Pod and out on track is where the CRX is most at home.

Its certainly perfectly acceptable for very accurate home results


I have some very very complex Excel spreadsheets from a couple of years ago showing just how detailed the GPS logging and speed calculations really are


Mark

 

[RBYCC]

Driftbox is a cheaper version of the Racelogic Vbox unit I have used when performance testing for magazines etc. I am sorely tempted to get one for myself as at the moment we only get accurate performance data from Santa Pod and out on track is where the CRX is most at home.

Its certainly perfectly acceptable for very accurate home results


I have some very very complex Excel spreadsheets from a couple of years ago showing just how detailed the GPS logging and speed calculations really are


Mark

Mark

Have you ever used the G-tech unit with the 3 axis accelerometer ?
Not GPS based.
Very accurate and data can be downloaded to a computer.

Ed A.

 

[bigyin1]

Driftbox is a cheaper version of the Racelogic Vbox unit I have used when performance testing for magazines etc. I am sorely tempted to get one for myself as at the moment we only get accurate performance data from Santa Pod and out on track is where the CRX is most at home.

Its certainly perfectly acceptable for very accurate home results


I have some very very complex Excel spreadsheets from a couple of years ago showing just how detailed the GPS logging and speed calculations really are


Mark

I could ask if I could get a group discount? My mate that works there is on holiday just now but i'll ask him when he gets back.

 

[Mark300SL]

Mark

Have you ever used the G-tech unit with the 3 axis accelerometer ?
Not GPS based.
Very accurate and data can be downloaded to a computer.

Ed A.

Ed I have one, and an AP22 etc etc

But I dont trust it as we compared figures at Santa Pod (FIA Dragstrip) and the Gtech was just too far out to treat seriously. GTech claimed rediculous accuracy that just wasnt realised in real life when compared to strip data accurate to a 100th of a second.


Mark

 

[Norse]

Uberwagon asked a interesting question in this thread.::

What happens when you put a car with antispin on a dyno??? As on my E-class, when the rear wheels start to move and the front wheels are standing still won't the antispin kill the throttle??

 

[Bobby Dazzler]

It's possible to put the car in "dyno" mode which is a supposedly a "secret" setting which can be accessed using similar menus to those which are used to switch between KPH and MPH, adjust timing for interior lights, etc.

Dyno mode disables systems such as ESP, ASR, ABS, etc and hence the reason it's a "secret" setting - it removes all safety systems, and so in the wrong hands and on the road it could be dangerous!

 

[sebyuk]

engine problems

hy i buy a mercedes c 220 cdi automatic 2002 and i have a problem with this car is not going moor then 3000 rotation and i dont now way?


is somebody to helpp me please

 

[BlackC55]

Ask a new question in the engine section.

 

[arkamelis]

wow dont you just love this guy, think il take my car to him when it needs tuning up
Thanks for the info Mark