Strange Tuning Question

[TooMuch03]

So last night I was thinking... generally this is when the problems arise. I was thinking about tuning, specifically the difference between towing tunes and race or street tunes. I generally use one street/race tune and a towing tune. I have always kinda liked the idea of having a single do it all tune.

When you push the button to switch the truck to tow/haul mode, the transmission changes shift pressures, TC lockup, shift points, etc.. It does this regardless of whether the truck is tuned or stock. My question is would it be possible to have the engine change its fueling tables, pulse width, timing, etc. from a race file to act like a tow file just by pushing that button? If it isn't possible, why not? If it is, why hasn't it been done or attempted?

Just brainstorming again...

[cartmanea]

Interesting idea. I know tuners will do special things in tow/haul mode, like lock out OD and such. Maybe there is limited space in the PCM memory that would prevent this from working, but I'd be all for it!

[DEVERO2]

I like that thought. Then you would never have to worry about remembering the tune. Just hit tow/haul like normal and you are good to go.

[hvac man]

Vivian's aggressive tow comes close. There seems to be more engine response w/o the tow haul engaged, and the shift points definitly change.

[sootman73]

with what limited knowledge I have on programming there could be an issue with available memory. I think it would require some pretty in depth programming changes to the software structure. You would have to have a data table(or multiple tables) to pull information from and you may not have enough available registers to do this programming change. Tuners would most likely not be able to do this as they change parameters in a program and then their software writes the tune file.

[Lilpooh]

I had asked a similar question, here is the answer I got.

ATTN: SCT & Tune writers?


Sent from AutoGuide.com App

[cartmanea]

Similar question, but different implementation. You were asking about a shift-on-the-fly setup whereas this would enable that functionality using the Tow/Haul mode. I guess the difference would be, your question required the tuner connected and switching done on the tuner, whereas using Tow/Haul puts it all in the program and is likely more feasible.

[kdogg85]

It could if the tow/haul button actually communicates with the PCM and not just the tcm. Or if the tunes can be setup to look at the tcm parameters and make fueling changes that way. I don't know of a PCM that has a memory setup for that, would be nice though.

[Lilpooh]

I would think that it's the same concept, Mitch pointed out that the PCM is flashed with the SCT for that specific tune (race,tow). I would imagine there is only enough memory room in the PCM to hold one set of parameters.

His second paragraph seem feasible if there are extra memory slots in the PCM.


Sent from AutoGuide.com App

[TooMuch03]

Originally Posted by cartmanea

Similar question, but different implementation. You were asking about a shift-on-the-fly setup whereas this would enable that functionality using the Tow/Haul mode. I guess the difference would be, your question required the tuner connected and switching done on the tuner, whereas using Tow/Haul puts it all in the program and is likely more feasible.

Right. What got me thinking was that when you engage to/haul, the TCM, which is integral to the PCM, switches to a different set of tables and parameters for better towing performance. Why can't the ECM, also integral to the PCM, do the same thing? Is there not enough memory? Or has no one figured out how to do it? The ECM also uses different tables for cold operation vs. normal, it would be the same idea, but instead of the switch to the modified tables being triggered by engine temperature, it would be triggered by the tow/haul mode being engaged.