This is one of the best threads I've seen on here about this.
This is one of the best threads I've seen on here about this.
Still confused as to why the PCM is calculating such a huge difference for hp/tq between VE and NN tuning.
Listen to this ^^^ which is also my preference - unless the car is equipped with a rowdy cam, then turning off ANN makes the idle/driveabilty tuning easier.Originally Posted by Hemituna
I love to break all the rules it seems...
Tuning with NN on, I set-up PE as an adder above stoich for my required AFR target.
Then I tweak fuel mass till that target is achieved.
So now if I make changes to PE, actual AFR pretty well follows what I command.
I thought this was common practice no?? Or is everyone still doing the DS NN thing of screwing the PE way up/down to get fuelling kinda correct at WOT??
I often add extra break points for Inj Ms also to get it real nice.
I VE tuned my car and it ran very well. It's currently an NA 5.7 Challenger at 12.0 @ 112.5 in the 1/4. I am switching over leaving ANN on to see if there are any advantages. So far, the first thing I noticed is that I used to run lean on part throttle when the ECTs were really low. If I compensated by changing the ECT VE Correction factor table, it would throw my full throttle tuning all out of whack. Once my car hit 120* on the ECTs it would all correct itself anyway. With ANN on, I'm not seeing this swing.
My wideband just started throwing error codes or I would attempt to get an updated 1/4 mile time on Saturday. Instead, I'm going to tweak my buddy's Charger (VE tune) and then switch him to ANN to see which can pull a better time.
2013 Dodge Challenger RT Plus - Shaker
It is completely.. But working around injector offset scaling and adjusting your FA commanded to get a certain AFR across the point is the wrong way to do it.
Every car I've tuned I've disabled the NN and tuned according, Start up, Idle, Transient and WOT. I guess there's a right way and a lazy way.
Bader Norris
MEP Tuned
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The end result is what really matters. Sometimes there are different ways to get there and people get hung up on what is the "right way" to do it. In the end if two cars drive the same, run just as well as each other, and are just as consistent and safe I would consider the tunes pretty equal even if two completely different approaches were taken to get there.
If you can point out issues with a tune done one way and not a different way then that's different
So as I mentioned above, I'm trying out the method of tuning with ANN on. To help with scaling the injectors, it would seem that a table set up to show Fuel Trims (STFT + LTFT) with fuel mass to RPM would help. See below. The thought being that as long as you required a sizable count of maybe 25-30 hits per cell, you could drop this into an Excel doc that would quickly average each row and give you a good idea how much adjustment you need.
2017-03-11 20_31_27-VCM Scanner_ 2013 Dodge Challenger R_T, 5.7 L, 8 Cyl, 2C3CDYBT0DH579357 [031.png
2013 Dodge Challenger RT Plus - Shaker
what i discovered these days i tune the car on the dyno on 12.4 AFR
on the street it goes to 13, i rework it to 12.4 or 12.5. next week 11.9 then i rework it to 12.4 then it goes to 13 afterwards !!
especially 6.4 across all its models. could NN cause this issue ??
I noticed that with VE tuning as well. Then I noticed that the load from the gearing seemed to have a lot to do with it. It's a little leaner in 1st and 2nd, right on in 3rd and then slightly more rich in 4th. I run an A5.
2013 Dodge Challenger RT Plus - Shaker
i tune on 4th if the car on 3.06 or 3rd if it is 2.82 or less.
HellcatANN.jpg
AFAIK there's no reason to have RPM in that hitso if you are leaving the ANN on. That's not how that table is in the tune. This is how I do it but that's just me.
That's the reason I posted it. I wanted some constructive feedback so thanks. I'll rework it like yours to give that a shot.
2013 Dodge Challenger RT Plus - Shaker
On a dyno? I have 3.92's and I have a nice long, remote straight stretch on a rural area to use.
2013 Dodge Challenger RT Plus - Shaker
Copy the Row Axis label of thte InPW v Fuel Mass table for the histo, use the Fuel Mass for Cylinder 1 and STFT, LTFT or both depending on what you are doing. One thing I have found in the Dodge tunes that I've done is there isn't enough breakpoints for the the area you actually need to tune. Depending on what your trims are you might have to rescale the table to give better resolution.
I used ID1700's on that Hellcat and had Paul@ID gave me data with those breakpoints to make things a lot easier for me.
Attachment 67428
Here is what my histo setup looks like. For STFT or LTFT(or both) go under the Generic Sensors and select them there. In Generic they are listed as STFT and LTFT, that's the average between to the two banks. This is easier than having to make a math channel to average each bank out. For driviability I use STFT and LTFT and for WOT I use just STFT since LTFT aren't used(Hellcat only).
However, if you are tuning a Dodge that isn't a Hellcat and doesn't have factory widebands you will have to set up a histo to log Lambda Err vs Fuel Mass instead of fuel trims vs. Fuel Mass.
If you aren't using Lambda do yourself a favor and do so. It's so much easier and faster than AFR.
Last edited by Jay@HAP; 03-13-2017 at 01:04 PM.
I was just noticing on the Hellcat we have in the shop that when the NN is off that it uses both VE banks even with the VE bank 2 set to disabled. We have 1300cc injectors and upper lower pulley and it seems to be having real trouble with some sort of base airflow calc ( the car seems to hunt like CRAZY ) and pull it self with the NN off. AFRs are right where they should be but the car hunts with the NN off. I feel like the IPW scale to tune is just wrong but if it makes the car run clean I dont care lol. Seems like theres all sorts of corrective functions running even with Closed loop is shut off and the NN is off still.
Doc
Doc's Performance & Dyno Tuning - Las Vegas NV . Tuning any and all cars!
Turning off NN means you have to correct little things in the tune that NN is adjusting for you. I wish Dodge setup all the tables correctly for NN off but things like cold starts often aren't very good with NN off without other places in the tune being adjusted. I don't have much experience with Dodges but do not mess with turning off NN because of the little quirks that are too difficult to anticipate. I have a 392 Hemi daily driver and just don't see where it drives any better with NN off either.
The using both banks even with the switch set to only use one seems like a normal thing too. When I first started doing a VE tune with NN off I noticed that it was still using the VE table for that bank.
I wanna learn how to tune the entire NN - I only deal with cars that are high end and weird - so having to rely on the NN is not something I prefer to do =)
Doc
Doc's Performance & Dyno Tuning - Las Vegas NV . Tuning any and all cars!
so this is my tune what i need to start tuning the VE please
jeep.hpt
So when we make a histo of trims vs fuel mass what do you do with that data? Obviously cant copy and multiply cause its backwards logic correct? Positive trim would mean decrease in fuel mass
this is of course non hellcat based. In theory could you not set up a custom math parameter and multiply it by -1 to invert it.
i.e- (STFT+LTFT) *-1
Last edited by bkg06gto; 03-22-2017 at 09:33 PM.
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