Just sat in my car logging it idleing with a few revs to see if the graph works okay.

All is good, SWMBO is going to hold the laptop later whilst i take it for a blast.

I just did a second run and plotted it into excel.The graph Looks looks great.

I did my run in third gear this time instead of forth which they say is the most accurate. The figure were torque - 183.7lb/ft (still quite high)

power- 175hp lower than before.

Allow plenty of time if you want to plot the chart.

octavia_vrs.pdf

why only rev it to 5500 when the engine revs happily to between 6500 and 7000 rpm? :confused:

as bhp is a product of (torqueXrpm)/5252 making the torque higher in the rev range means more bhp even if its the same torque reading.

If you are refering to my first post the torque started to drop off after 4000rpm and that was the highest bhp reading over the run.

The second posted chart i took it to 6500rpm.

ahhh, i haven't actually looked at that yet

Quick question but do turboed cars reach their max bhp before normally aspirated cars? (in the rev range)

normally as tehy make the torque lower but not always, my mazda which is an old skool 1.6T makes peak torque at about 5500rpm and peak power at about 6500 or something silly.

Next time remind me not to take SWMBO in the car with me.

Got such a Roasting.................speed limit............blah blah.............police, blah blah, stop going so fast blah, blah and all this before i reached 60 on the motorway.

Will have to try again sometime soon on my own. Im in the bad books now.

Next time remind me not to take SWMBO in the car with me.

Got such a Roasting.................speed limit............blah blah.............police, blah blah, stop going so fast blah, blah and all this before i reached 60 on the motorway.

Will have to try again sometime soon on my own. Im in the bad books now.

:rofl: ........... Tell her i told you to do i, blame me, I'm always in the 5hit with women

Oh and next time don't take her with you

Sorry to revive an old thread, but this is the closest i've come to finding the answer i'm looking for.

I'm pretty hopeless with excel/open office when it comes to graphs and formulas, so if someone can offer me a few tips i'd be gratefull.

I need to sort the formula for getting my NM converted to Lb-Ft (i have a torque converter, but i don't want to convert hundereds of figures myself if i can help it) so if anyone knows of a dummy guide, that would be great.

Then i need to know how to multiple RPM by Lb-Ft divided by 5252 in order to get BHP. I have no idea how this is done either, so again all help is gratefully received.

I think i should be able to graph it all from there, but any further tips would be great.

(i should point out that i tried the guide on page 1 but had no luck :( )

Did you look at this?http://www.ross-tech.net/vag-com/examples/Block_120_Tutorial.xls

Did you look at this?http://www.ross-tech.net/vag-com/examples/Block_120_Tutorial.xls

Yeah, that link was on the first page. I just can't seem to figure it out.

Was hoping someone might be able to explain it a bit better. I really am hopeless with this stuff.

Thanks for the link though

You need to create 2 new columns bhp and torque.You have to convert every figure to Lb ft first (Nm x 0.738)These figures go in the first column, Thats the way i did it and i didn't find a way around it.

The equation for the hp figure is lb ft x RPM/5252

This will give you your hp figure for the second column.You need to do this for each set of figures.

Then follow the the rest of the instructions.

It is a very lengthy procedure but the graph at the end looks good as my pdf file shows.

You can work out your highest bhp/torque without plotting the graph by taking the best figures and working them out.

You need to create 2 new columns bhp and torque.You have to convert every figure to Lb ft first (Nm x 0.738)These figures go in the first column, Thats the way i did it and i didn't find a way around it.

The equation for the hp figure is lb ft x RPM/5252

This will give you your hp figure for the second column.You need to do this for each set of figures.

Then follow the the rest of the instructions.

It is a very lengthy procedure but the graph at the end looks good as my pdf file shows.

You can work out your highest bhp/torque without plotting the graph by taking the best figures and working them out.

Cheers mate.

I didn't realise i had to do the NM>LB-FT conversion myself, and then graph the BHP from there. I thought there was a formula that could do it for me, so no wonder i couldn't do it.

Will have a go now

post us a graph when/if you get it done will ya

post us a graph when/if you get it done will ya

If i can, i will (whats the best way? i really am hopeless )

Here is the graph with all the log and conversions incase anyone wants to check it?

I think it's quite high, but not complaining if it isn't.

block 20 graph.zip

VAGcom calculates torque and bhp values based on sensor readings - MAF, MAP pressure, temperature, ignition timing, amongst others. It makes some assumptions about engine efficiencies and calculates the output based broadly on the amount of air the engine is consuming.

Nice graph.

what gear did you take the readings in.

Glad to see you got it working.

VAGcom calculates torque and bhp values based on sensor readings - MAF, MAP pressure, temperature, ignition timing, amongst others. It makes some assumptions about engine efficiencies and calculates the output based broadly on the amount of air the engine is consuming.

Does that make it more, or less accurate than a set of rollers? :confused:

Nice graph.

what gear did you take the readings in.

Glad to see you got it working.

I had a quick look at the Butt Dyno page, and mentioned taking the log in a gear that i could get through the rev range without breaking the speed limit. 3rd seemed to be the right gear for a dual carriageway, so i logged 3rd.

I had a quick look at the Butt Dyno page, and mentioned taking the log in a gear that i could get through the rev range without breaking the speed limit. 3rd seemed to be the right gear for a dual carriageway, so i logged 3rd.

I'd make third at full chat to be about 110 on the speedo .

Must get around to doing this myself when I can find a suitable quiet bit of "private" road one night...........:P

I'd make third at full chat to be about 110 on the speedo .

Must get around to doing this myself when I can find a suitable quiet bit of "private" road one night...........:P

110? KMH?

Or is that in a Petrol?

Mines TDI and full chat in 3rd is aprox 70-80mph.