Discussion and questions related to the course Practical Dyno Tuning
For me at the moment, one of the more daunting aspects of tuning relate to the initial setup of the ECU and all the different compensation tables, settings etc to run on each specific ECU. Could I assume that before you can really "get good" at deciphering all these settings and using them to your advantage that you really must become familiar with each particular ECU before you can really tune with them? I figure the more exposure you have to certain brand (and engine type for that matter) the better results your going to get, right?
I also just bought an Adaptronic ECU so if you ever had plans to demo one that'd be sweet ;)
Looking through known good base maps and larger model specific forums to understand stuff like sequential turbo control, or oil metering pumps (rotary) as well as known model specific issues like common "wonky" IAT correction to deal with manifold heat soak or sensor offsets and other additional compensation maps makes a big difference. Most ecus should have an explanation of their fuel model process in the tuning software or manual but it isn't always fully documented. If they have a simulation system that can be useful too. With most moving to fuel film models it should get a lot easier as acceleration enrichment between brands can be like comparing carbs with fixed volume throttle pumps with constant velocity or tapered slide etc, probably the trickiest part if they are not documented thoroughly. It can pay to look at a basemap vs modified setup with fuel pressure compensation as well as you get a better idea of the real engine VE as opposed to uncompensated fuel tables which absorb correction associated with fuel pressure regulator sag which is ususually worse on factory regs (this is also a trap for inflated egos trying to back calculate airflow/power with assumed BS air or fuel consumption without fuel pressure correction "I'm at 87% inj DC with 700s so I'm making ~XXXhp"). Injector staging strategy can also be quite different between ecus or different modes in the ssme ecu.
Sounds like good advice, thanks mate. Still so much to learn!
Speaking of Accel enrichment, I don’t see Andre making a lot of changes in this area in the worked examples. It sounds like that is truly where tuning becomes an art form when you have to respond to how the car feels on the road. It would be fairly hard to tune for accel and decel tables using just the numbers alone, no?
If your wideband step response/logging frequency is poor it will be more difficult to do by numbers but most modern systems should be good enough if you have worked out how the acceleration enrichment actually works, if it is % of measured intantaneous load multiplied by throttle movement rate or something else for the initial enrichment, and how the decay works. There is obviously a small delay in most MAP load based ecus which is why throttle enrichment is required, likewise you need to understand the combined "transit time" of the exhaust gas (which changes with load/engine speed)and sensor response to understand what is happening when you stsb the throttle.
If you are working with older gear with low logging frequency you still want to see what data pounts you have match your target lambda values for the loads you transition through, but could be a big of guesswork where car feel helps.