VersaTune User Forum

Is it possible to implement Roll Launch on our ECU? And also, is it possible to implement the function of switching ignition maps in real time, say, from a button on the steering wheel? It would be convenient for those who have two tunes, one for methanol, the other without.

Not really, the factory ECUs in general do not have additional inputs to work with. Also remember we're basically changing the calibration tables, the actual/original ECU logic is not altered.

mituc wrote: ↑November 17th, 2021, 9:53 pm Also remember we're basically changing the calibration tables, the actual/original ECU logic is not altered.

Quite a shame, especially when compared to ECUs from other manufacturers (for example, LS engine ECUs from General Motors. How I wish we could toggle the MAF and run speed density!).

ahayden04 wrote: ↑May 31st, 2022, 7:34 pm Quite a shame, especially when compared to ECUs from other manufacturers (for example, LS engine ECUs from General Motors.

Brake boosting works just as good.
Are you sure you don't need a stand-alone ECU even on the LS platform to make anti-lag and rolling launch work?
Also keep in mind these are ECUs designed in the early 2000's, while the LS platform kept going on the marked even to this date.

ahayden04 wrote: ↑May 31st, 2022, 7:34 pm How I wish we could toggle the MAF and run speed density!).

Well, speed density is actually a downgrade from having a MAF sensor.

Also keep in mind these are ECUs designed in the early 2000's, while the LS platform kept going on the marked even to this date.

Absolutely. I was referring to our ECUs having logic that aren't as clear/exposed, whereas even the 1999 GM ECUs were fully unlockable and accessible, albeit less feature rich.

Well, speed density is actually a downgrade from having a MAF sensor.

Indeed, but for development purposes, having the ability to turn off the MAF and fuel trims is unbelievably helpful. To do my speed density, I allowed HPTuners to do math tables and auto-populate values. Once it was done, I left fuel trims off during MAF calibration (only looking at AFR differences). It was definitely easier than worrying about transitions from Closed Loop to Open Loop Now I run the MAF obviously

ahayden04 wrote: ↑June 2nd, 2022, 1:33 am Indeed, but for development purposes, having the ability to turn off the MAF and fuel trims is unbelievably helpful.

This is a pretty well researched platform so to be honest I'm not sure what R&D process would make this useful.
However, turning off the fuel trims entirely (or just in closed loop) is perfectly and easily do-able. Actually I do turn them off in open loop in all my tunes. There are pro's and con's to this: by example if something happens with the intake or MAF (some hose cracks, MAF gets dirty, and so on) you will have no corrections on the fueling. On the other hand with all things intact the ECU will have one less thing to worry about and the difference in response can be felt quite a bit inn certain situations.

As for when doing work on the MAF cal you can still look at the fuel trims to apply corrections to the actual MAF calibration. You can also import one of the pre-existing MAF calibration from the dedicated thread (or request for one there) and you will have a lot less work to do so you can use the gained time to work on the rest of your tune.

Also keep in mind that the way the logic from the OEM firmware may be altered by only changing the values in these calibration tables we have access to, but the actual logic embedded in that firmware cannot be changed. By example you can prevent a tune to ever go into open loop (say, you tune for full time closed loop), but if you allow the tune to go from closed loop to open loop then you cannot change what tables to use, as the firmware logic will transition from the closed loop tables to the open loop ones. You are only tuning the transition point, but not the actual process.