I have been playing with the idea for a while of writing an Auto Tune program.

Kind of like Map Tracer, but it would make changes to maps and items for you.
It would be aimed toward beginners and get the basic items set up for you.
Like Injector Size and Latency, MAF Scaling, VE for SD, etc.

I have been thinking about the Fuel part of it and wondering what would be the correct equation.

Like for WOT:
Injector Size % change = 1 - (WideBand_AFR / AFR_MAP)

If the Map was 12 and WideBand 11:
Injector Size % change = 1 - ( 11 / 12) = +8.3%
It would increase Injector Size 8.3% to lean things out.

Would this equation work? I'm not sure if you would have to account for anything else, or since Injector Size is a volume/time it would change anything.


Anyone have any thoughts or know of any software like this?

 

With all the additional corrections (lean spool, baro, temp, acceleration enrichment, injector latency), I think it will be significantly more complicated then that.

You also need to be careful how you approach the changes, as it's better to work slowly up to the desired AFR vs. trying to hit it all at once.

Autotuning works well at low loads, but I wouldn't put it in the hands of a beginner for WOT tuning. Cool idea though and would definitely be a valuable tool for injector scaling and latency if you worked the injector latency table into it.

Doing something that was less live tuning, but maybe more like statistical based logging and analysis setup to eliminate/filter the unimportant data and compensate for the additional corrections might also be very useful.

 

i think it would be nice for VE on SD lol or like they said tuning low load cruising. they have this feature on power commanders and stuff for bikes. it basically logs the A/F and map traces it and you input what AFR you want at each point on the map and it recomends changes to the map to get you desired AFR.

 

Auto tuning on the autronic and the AFR tracking on the MAFT Pro have been around for awhile but its always been kinda iffy. Havent played around with it on the PC3 and PC5 but not sure if it would work with boost fast enough anyway.

 

AFR_MAP(Request 32) has most of the corrections added to it, I believe. If not a different MUT Request would be used. Latency has minimal effect at WOT. Throttle changes would be filtered out, only 100% TPS would be used for Injector Size Tuning.

Injector Latency Tuning would be done from Idle and Low Load Cruising Logs.

 

And would you use MAF scaling in there anywhere?

 

You're touching on the first thing that came to my mind way back when jcsbanks originally posted his live mapping patches: not just automatically making adjustments to maps on disk, but potentially pushing them to the car in real-time.

 

wow u guys work fast

it would be nice for SD and VE, maybe someother stuff. other than that, there are too many parameters that feed into it IMO.

hmmm when will there be an autotune that adjusts timing just below 1* of knock

 

the optimum timing isnt always 1* before the knock threshold. it is MBT so tuning timing based on that logic would not yield the bst results. especially on E85

 

i know but it would "put" you in the right place to start and it would make it easy for pump gas guys granted the knock sensor behaves...

 

Maybe, maybe not...

All depends if the car is knock limited ( makes MBT past knock), or not. Subaru's will often knock and have the power keep rising because the other pistons are still getting good combustion events, and the power generated by the extra timing in those other cylinders is more than enough to make up for the power lost in the knock event cylinder.

Scorke

 

WOT autotuning is almost never used. It's just too risky. Sensor response time, data filtering, and careful increment control is extremely critical. Autotune (at the level implemented by most standalones) IMO is strictly for low load tuning.

I guess if you wanted to go full time closed loop you could give it a shot. Sounds EXTREMELY sketchy though. You don't want it to cycle around your tuning point at all, as 0.5:1 change in AFR is massive on pump gas and could easily lead to engine damage. You would want some long term control that slowly adjusted and tried to never go leaner then your target.

But hey, I don't really mean to be a nah-sayer. I'm just pointing out that WOT auto-tuning is actually a very sophisticated system when done correctly. If you are going to put the effort into doing it, I just hope you see the larger picture and can implement it without all the short comings that most systems have.

I've used the auto-tuning on an Autronic. Yes, it is AWESOME for mapping the car when you have like 30 load sites and 30 RPM sites and you limit it down to low loads and engine speeds. You can define what conditions it becomes active. Take a 20 minute drive down the freeway and the car has nearly perfect AFRs. A few minutes smoothing and the car runs great. For a standalone on speed density, 20 minutes to tune part throttle is awesome.

But it is complete crap for trying to tune idle conditions and I would even consider using it at WOT. At cruise, it's not uncommon to see it running 2.0 full points lean as it searches for the target AFR.

 

i think the auto tune would be beneficial for SD aplications mainly. or for DIY tuners like how its used with the PC5 on bikes. thats my .02 hope this comes to fruition before i have to tune VE for my SD setup lol make my life easier.

 

You might be surprised, but modern VW cars run full time closed loop... even in WOT areas.

That said, I don't think this is good at all for WOT. I like it for MAF Correction (DSMLink/ECMTune does this) but not for most other applications. Humans are smarter than computers when it comes to this... and the adjustments you are talking about are some of the easiest to "get close" before a human would have to step in for the program anyway.

 

Closed loop AFR in boost is a big negative.