Anyway of comparing torque figures from 2 different dynos?

[No Crust Racing]

Anyway of comparing torque figures from 2 different dynos?

See attached images. Old graph (Dyno Dynamics), with higher power and lower torque was done 3-4yrs ago using SAFC and SITC.

The only change, new graph on Mainlne, was a Nistune, so I could have some proper off boost/part throttle behaviour and smooth out that torque dip (through controlling the inlet butterflies properly).

Is there any way to compare the very different torque readings wit the info at hand? 

 

 

[GTSBoy]

Just back calculate a torque number from the power using the normal formula.  It won't be numerically correct, but because it comes from the only thing that actually matters (power at the roller) at least you're starting from the same basis* and can draw graphs to compare.

 

*of course, excepting the different dynos, operators, tyres, years in between, etc etc etc.

[No Crust Racing]

I have torque numbers from both dynos. They are very different (360Nm vs 550 or so). 

I know power is just a function of torque vs revs, but given these dynos do various corrections to get their numbers, I have no idea how to apply anything to either number to find something meaningful between them. 

 

 

 

[Piggaz]

http://www.wentec.com/unipower/calculators/power_torque.asp

If in speed, work out RPM.

[Dose Pipe Sutututu]

It's because the operator on the Mainline didn't use an inductive pickup OR setup the derived RPM via syncing RPM.

Once that is enabled you can select show 'Derived Torque' 

/Thread 

[No Crust Racing]

Even when plugging figures into calculators with known RPM, the output is not like either graph. 

All smoke and mirrors. 

Oh well, see how it goes Sunday and will just hope that a smoother graph means a better car to drive (yes i know graphs can be smoothed also).

[Scott Black]

http://docs.google.com/gview?embedded=true&url=http://www.mainlineauto.com.au/images/downloads/DYNO_TORQUE_FIGURES_-_THE_TRUTH.pdf

I posted this in a differnt thread a week or so ago. Should help you understand a bit better

[Scott Black]

Also the power diffence is sfa when considering its 2 differnt dynos on 2 different days, I'd love to see the boost plot from the dd run as a tiny overboost would explain the hump around 4g on the dd graph

Also the 550nm mainline number in this case would definitely be the bs number as with out a rpm trace there's no way it can give torque reading with reference to the engine

 

[KiwiRS4T]

If you are not measuring the same car on the same dyno on the same day a good way of telling the improvement is to compare say 80 to 120 km/hr times - too late for you now of course. Does the car feel better to drive now?

[Dose Pipe Sutututu]

1 hour ago, Scott Black said:

Also the power diffence is sfa when considering its 2 differnt dynos on 2 different days, I'd love to see the boost plot from the dd run as a tiny overboost would explain the hump around 4g on the dd graph

Also the 550nm mainline number in this case would definitely be the bs number as with out a rpm trace there's no way it can give torque reading with reference to the engine

 

Boom! Someone that knows

[No Crust Racing]

Quick report from track day. 

Car felt gutless, no surge of torque when it comes on boost. Also a little bit pinging somewhere up in 3rd, was not logging so cannot tell. Had a few misses/hesitation when cornering (car has surge tank setup) though tuner did note fuel pressure was fluctuating quite a bit with temperature. 

Despite the car feeling gutless and less powerful than I remember it (a few years ago) the max top speed down the straight was identical and the lap time was within 1 tenth of the previous PB 0_0

 

 

[GTofuS-T]

Are you sure it's not just gutless compared to the GTR?

[No Crust Racing]

Given the max top speed was the same, I'd say so. 

Though I need my old phone to look at the Race Chrono data and see if the corner exit speed onto the straight is the same to be sure. 

[Dose Pipe Sutututu]

car runs a Nistune with feature pack, I say jack up the FPR to 4 bar run flex fuel

 

[No Crust Racing]

Not after seeing GT-Rs "economy" on e85 and the fact I can't get it here. Annoying enough bringing back 80L at ta time for the GTR (which ate 140L at winton...) 

Silvia wouldn't be as bad, but still. That means injectors and a full retune on e85, or additional e-flex sensor then really should go to proper boost control etc etc.