Discussion and questions related to the course MoTeC M1 Software Tutorial
I was on the dyno lastnight tuning on of our cars i tuned the VE table within 3% trims on the ntk wide band.... Did my first wot run on dyno it made 900whp... On the 2nd run the whole VE table was too rich !!!! Over 15% so this didnt make sense to me i attached dyno wide band and it was 1 point in the afr richer then the ones on the car keep in mind i am using proper injector data fuel prssure sensor fuel regulator manifold refernced ......wat cld have happened
If the VE fuel model is working correctly I've found it to remain exceptionally stable from run to run - Definitely you shouldn't be expecting to see a run to run variation of 15%!
I would be looking initially at what had changed between these two runs that could have affected the fuel calculation to ensure that your runs are in fact comparable. Was the boost pressure and inlet manifold temperature similar? How about fuel pressure? Also make sure that you aren't applying any mixture aim trims that you're not aware of for aspects such as inlet manifold temperature or engine temperature for example.
If the runs appear to be under identical conditions but you're seeing such a dramatic difference in lambda, I'd also look at what the delivered injector pulse width is. If this is identical between the runs yet you have a lambda variation then something else is affecting the engine operation outside of the ECUs control.
With regard to the lambda sensors, it's not uncommon to find that 2 widebands will read differently to each other and a difference of 0.1 AFR is actually pretty good in my experience.