Hello everyone, this maybe a dumb question but how reliable are HP/Torque figures gathered from OBDII apps?
Not as HP/Torque numbers compared to the real ones, but for example I was getting 160Nm of torque on my 86hp 1.2 but now Im getting 135Nm max, can this mean I'm loosing torque ?

I’ve found as for torque values it never comes close. I’ve had two dyno runs First was 261ftlbs second was 258ftlbs and the app shows no where near that figure.

 

On the other had the wheel horse power figure seems to be very close! Always worked out when doing it my car was around 150hp which was proven on my dyno run at the end of last year. I used the OBD 2 dyno app on Android it gives you a actual dyno graph on wheel hp.

 

Richard

The app uses accelerometer or GPS data to determine the acceleration, and the values for the vehicle weight so the accuracy is dependant on all those factors. The better the calibration and info you put in, the better the data you will get back. 

 

I have found the most reliable way to measure acceleration is with an accelerometer app like PerfExpert. Don't bother with dyno mode, a timed run in 3rd or 4th gear pull will produce a nice repeatable graph which will closely mirror your torque and boost curve.

Thank you for your answers, but my question being, if with the same car, same weight, same car values put on the app, same app but different runs, can a big dip in torque mean a real loss ?

Not even close when mine did it it was something like 700bhp. 

Sure but if one day, for example, I get 500 torque from 5 pulls, and the next day I get 200 can it mean my car lost some torque ?

It's possible yeah, but to be honest they are so unreliable it's not worth bothering. Like I said, logging the actual acceleration g through a gear won't give you a torque figure, but it will give you a graph you can compare to other runs and gauge relative performance.

Edited 14 January, 20188 yr by FlexibleMouse

9 minutes ago, FlexibleMouse said:

It's possible yeah, but to be honest they are so unreliable it's not worth bothering. Like I said, logging the actual acceleration g through a gear won't give you a torque figure, but it will give you a graph you can compare to other runs and gauge relative performance.

I'll give it a try, thank you !

No problem, if you do a 3rd gear timed run pull post it here so we can see how our cars compare. As you can see from my graph the peak torque is from the supercharger, then there is a dip while the supercharger disengages and the turbo is still spooling.