Hi I'm very new and trying to understand tuning hoping to get to a HP class soon, but reading thru the forum I see a lot of reference to Neural and VE, can somebody explain or point me where I can find the difference between the two, and the tuning differences as far as performance.
Thanks
Neural Network is a very sophisticated... Google has tons of info. VE is short for Volumetric Efficiency, Google has tons of info on that too. Not being a jerk but you'll learn a lot more from studying multiple sources than what I could ever type here.
I did a search and found nothing related to tuning but thanks.
You cannot tune NN, its all predefined maths within the logic of the PCM. Your inputs are very limited, mostly just your engine size, displacement, and injector size and settings. Beyond that the PCM will do its own algos on airflow and torque. You can read about HOW the PCM does the math, but in no way would you ever want to start trying to mess with the predefined algos the engineers spent years figuring out. Your VE table becomes somewhat redundant when NN is still on, its one of many inputs to the formula, whereas when you turn off NN it is one of only a FEW inputs to the math.
For a lightly modded car, NN calcs will still be close enough to leave it on. Once you go boosted or heavily modded, you will want to kill the NN and work from the ground up on your VE table and airflows.
Thanks that helps.Originally Posted by 06300CSRT8
After rereading your question I see I missed the last part so my apologies. I thought you just wanted to understand what each was. Thanks 06300CSRT8 for being helpful.
Yeah, what happens inside the NN is a f'n mystery.
In fact, a lot of what happens even when it's turned off and the VE is manually tuned is an equal mystery.
I would have to agree lol
Until recently, I would have agreed totally with the above comments.
But of late, I have found the latest vehicles (2014/15/16) work better with the NN on.
The NN is so interlaced with so many functions, that turning it off causes more drivability issues than it solves.
I've had a few battles recently getting 15 and later year models to drive as nice as I want.
Eg. Tuned a 2015 Whippled Jeep SRT with NN off. Made great power, drove good, but had a couple of drivability niggles that couldn't get on top of.
Spent days and days fiddling and don't get me wrong, the thing went good, most would be more than happy.
But I'm a stickler for perfect manners and just couldn't quite get it spot on.
So gave in and started tune again with NN on. Within just a couple of hours it was sensational, has never driven better, trans is buttery smooth but shifts solid, engine is super responsive and has perfect start/idle, cruise, transients, pedal feel with no drivability niggles at all.
I have redone a couple of other 14+ tunes now that were frustrating me also and have had the same result.
So maybe don't toss the NN out just yet, even on more modded and boosted cars.
Is your WOT fueling near commanded with NN on even with forced induction setups? I was curious after looking at my fuel trims driving around on a stock 392 if WOT hits target or not but haven't had time to put my wideband in.
Good recommendation here. We tune quite a few of the late models and have had the same experience. Keep the NN on and save yourself the aggravation.
How do you adjust fueling if it's wrong in open loop/PE situations without hacking the injector tables?
Fuel/Fuel Mass Multiplier/Vacuum Multiplier is your friend
Use PE table to get AFR nice and smooth, with maybe some trimming of the injectors.
No need to be precious about injector tables, they are a tool like anything else.
Hey - in a perfect world, changes to VE base table would be nice, but currently we have to work with what we have.
Great info, guessing they must have broadened out the NN logic to accommodate broader airflows including in boost and part throttle boost. I still love the simplicity of my older PCM but look forward to when I upgrade to having some easier times with tuning.
I tune everything with NN on.
Does that imply that you make changes with VE tables with NN enabled? Everyone who has posted anything about trying to tune with NN enabled reports that VE changes do not have any effect.
Maybe something is screwy with my mpg gauge in my 14 wrangler but it shows 11 mpg with NN enabled and 15-19 running off tuned VE.....both with identically altered cam timing.
Will have to hand calculate.
Damn, I have to eat my own words.......
After giving in and turning NN back on on that 15 whippled jeep, it drove real, real good.
But I can't live with the swings in AFR that NN on has.
Because the VE is incorrect and we are fudging inj scaling and modifiers to get a result, it is never really correct.
Wot is good and CL is good but in-between is really a bit of a crapshoot.
Drives great as long as you don't log the wideband. hahaha.
So I went back to NN off and had another go.
Found the niggles related to DFCO that were bothering me and now it is really AWESOME !!
Fueling etc is spot on..With NN off you have to define every little thing, where-as NN takes care of a lot of it for you.
So if you have the time and patience, NN off can be a winner...
What are the settings relayed to VE learning about? Is it something in addition to fuel trims? I turned it off when tuning my VE but would like to know what it's about. I haven't even thought to see if the scanner shows a parameter for anything related to this.
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