Had car on RR today, help needed on dyno graph

[CupraTDI_Rob]

I had my car on a rolling road today, and i'm a bit confused with the results and how to understand the graph.
The rolling road isn't a up to date one and it doesn't measure torque.

On the graph all it has is KM/H and KW and i'd like to know how the RPM and BHP was worked out from these figures.

Here is the graph

Results were 199BHP at 4100 rpm

And 254 lbs/ft torque and this is no where near what it should be, should be around 300 lbs/ft
The guy worked out the torque by doing this calculation 5250 X peak power divided by peak rpm.
So 5250 X 199 / 4100 = 254

But this calculation doesn't work on diesels, it only works on petrols, i have tried it on other petrol and diesel cars using manufacturers figures.

Any help on understanding the graph and how RPM and BHP is worked out from the graph would be greatly appreciated.

Cheers.

 

[devonmikeyboy]

I hope you didn`t pay for that dyno run.

 

[RobM]

Did they draw that graph by hand?

 

[lc_allan]

Did they draw that graph by hand?

I was just about to ask that...

This the place?

sorry

 

[DPJ]

Torque = Horsepower x 5252 / rpm

So, at the rpm where you are making maximum bhp, your torque would be 254 lb/ft.

But that's not the point where your engine makes maximum torque, is it.

 

[Big_daddy]

the graph dosnt look right, my inkjet printer can do better than that.

 

[devonmikeyboy]

I take it this is the place where you went.
http://www.t-m.co.uk/index.htm

 

[devonmikeyboy]

And this is thier veerrryyyy old dyno.
http://www.t-m.co.uk/rrd.JPG

 

[CupraTDI_Rob]

Having just looked at other dyno graphs on here its pretty piss poor in comparison.

Anyone know of any other RR that are in and around the Colchester area?

 

[lard44]

Engine Advantages in Witham has one that I know of, although I would pootle down the m25 to Big Boys Toys in Thurrock tbh.

 

[olaf]

BBT dont have a rolling road I dont think!

Place next door does though.

 

[lard44]

BBT dont have a rolling road I dont think!

Place next door does though.

Doh!

That's wot I meant honestly...

 

[ibizacupra]

those are gear changes as they work up the box yea?

power calc works on diesels too ya know.