Importance on Gen4 Virtual Torque?

[Alvin]

I think the basis of his point is using the injector scaling method.
.

Yeah.. And I'm saying that I've never ran in to anything like that as a issue. The box truck I mentioned above is a 07 or 08 NBS and has ID 1000's.. It's been scaled for maybe 200k miles? I originally did it in my old shop and I moved 10 years ago?

I think people confuse how critical GEN 5 torque is and think it applies to GEN 4.. Hell a lot of us will remember that we didn't get the ability to even modify GEN 4 toque until they had been out for maybe a decade?

[GHuggins]

I haven't had any transmissions burnt up either - even moving 14 to 20000 lbs around Just stated what I see coming from other tuners....

Also the torque model still effects everything on a gen 4 just like it does a gen V. Don't believe me really alter one and see how it drives. Plus as already stated even the OE makes them different for the same engines designed to move different weight. Wish Nathan was still around - he could comment on how it effected his LSA's engine behavior and trans functions...

[Alvin]

All this talk about "if you scale a tune you have to mess with torque" was bothering me..

So I took a Stock? Yukon in the parking lot.. Logged torque at an idle, read the file out... scaled the injectors. Cut the flow rate in half, doubled stoich, etc.. re-logged it.

Torque is exactly the same with the engine "thinking" half the fuel is getting to it. Torque is airflow biased like I known all along and if the airflow models are correct your torque will be as correct as it could be.


unscaled.hpl
scaled.hpl


I'm not trying to change your mind.. But people should know both sides of the story and for the amount of real world experience I've had.. I think my argument should be out there.


Also this talk of how heavy the vehicle is changes the torque??? The engine doesn't make any more or less torque when it is loaded more. The engine is going to produce what it produces.. to further that point.. I'd say a vehicle has a far greater difference in load in 1st gear vs 6th or whatever gear. There are not separate torque tables for that!? So adding torque to the tune because the vehicle is overloaded doesn't make much sense to me.

If your scaling torque up or down some arbitrary percentage to get the trans to shift harder... well you can just edit the shift firmness at the real torque you are at. If my airflow model is correct (first step in a tune) and I"m at 600 ft lbs and I want that shift firmer or whatever.. nothing wrong with changing the trans at that torque.. To manipulate that torque up and down to get a desired shift seems really wrong to me.

[GHuggins]

Get a driving log with both with the airflow models dialed in with light throttle As long as injectors scale out in your favor and you have to add air then your good, but what if you had to remove fuel? Also I've stated this several times - has nothing to do with shift pressures - has to do with hold pressure which the torque model controls - not the transmission. OE wouldn't do it if it wasn't important on the heavier trucks.... Think I've had this argument with you before - go to that thread and look at the vehicle files posted then that proved what I'm saying. Just saying this needs to be checked - you need to know which way you're shifting the tables!

[SiriusC1024]

So which of you two is the Burger King to the other's McDonalds in the NC tuning scene?

[GHuggins]

So which of you two is the Burger King to the other's McDonalds in the NC tuning scene?

LOL

I believe Alvin is down in flat country - Mooresville? - I lived there for a couple of years doing minor nascar stuff then moved back to the mountains.

[smokeshow]

The torque model on a gen4 is far more limited in what it does compared to gen 5. But it works all the same. Probably the most action you'll see out of a gen 4 torque model is downshift rev matching. Otherwise it's primarily idle control with some trans torque management sprinkled in.

[GHuggins]

The torque model on a gen4 is far more limited in what it does compared to gen 5. But it works all the same. Probably the most action you'll see out of a gen 4 torque model is downshift rev matching. Otherwise it's primarily idle control with some trans torque management sprinkled in.

Thank You Smoke...

Also something - I don't know kind of rubbed me wrong with an above statement that I wasn't going to comment on, but I "think" it needs to be clarified and just to make it clear I'm not here to argue or try and put anyone down as it constantly appears to be done to me, but...

Alvin said something here that's - well it's not wrong, but also not entirely right -

Torque is airflow biased like I known all along and if the airflow models are correct your torque will be as correct as it could be.

By this I'm referring to what the torque models reference. With the above statement it made me wonder if Alvin has played much with the torque models to understand what they are and if I'M WRONG - please someone such as Smoke or the other Greg - correct me

YES as I've already explained a little in this thread - just like nearly everything in a calibration there are two halves to the picture - two redundant's to self check one another if you will - a MAF side and a SD or MAP side to the torque models whereas the MAF side is used primarily for constant state and the map side is used or "leaned" on more so for quick pedal movements or "transient scenarios.

The MAP side of the torque model uses manifold air pressure and rpm as it's axis then defines torque via the corresponding timing for those tables... Think we all agree on that one.

On the MAF side - because I assume it's easier for the calibrators and as precise as it needs to be - it references CYLINDER AIRMASS vs rpm. I assume it's done this way because airmass is defined through dynamic air via the MAF and MAP models. Is it starting to click as to why fueling can throw things off yet?

So lets throw two scenarios in for explanation.

First off we have individual A - he's running a cammed motor with a blower and decides he needs injectors - he plans it out and gets injectors that fit his flow rate table via normal scaling - if it needs to be scaled at all to begin with and has to add air in everywhere including the idle and cruise zones of the MAF curve, hitting regular cyl air levels and even higher with the blower installed (one would assume no torque model editing would be needed other than the idle area technically and it would survive - right?)

Now let's throw in individual B - he's running a cammed motor, but has plans to install a MONSTER blower and run ethanol down the road, so he think's he's doing what's right and gets the biggest injectors he can but he doesn't want to necessarily spend the money "as things are way overpriced now" and he gets some "not so great brand xer's". Now the not so great brand xer's have injector data, so we have something going there, but due to their size and the ecm's limits we have to do a 30% or 40% scaling. What do we know that this does to the cylinder airmass level's??? Why do we scale the timing table if it's doing nothing??? Starting to put 2 and 2 together now

Now lets throw in the next part of the equation - brand xer's don't fit the flow rate table as we've discussed and requires us to pull air out of the idle and cruise areas of the MAF curve - this is on top of the scaling we've already done. If you didn't see the point before - you should now!!! So, we now have cylinder airmass levels that are lower. A MAF curve that is lower and you don't see a point in "maybe" needing to increase the torque model slightly if not more so on the MAF side and then in the lower regions of the map side??? If you don't by here, I can't help explain it much better because these are the two main extremes you or anyone might see.

I said this above -

Just saying this needs to be checked - you need to know which way you're shifting the tables!

I run into burnt up transmissions due to bad tuning or scaling often enough that it needed to be pointed out. It almost always has to do with bad scaling or bad injector data to begin with and a tune that's not fully done - such as a "MAF only" tune. I'm just trying to get the right information to those who can use it out there, so it may save them a $4000 or $6000 bill

If you don't believe it exist - just look at all the post on here where people are told "by their tuners" they need to upgrade their transmissions due to slipping and look at those tunes. I believe you stated it best when you were telling someone about getting a tune unlocked - that most the time the stuff is garbage and they're trying to cover it up That was another statement you made.

Never meant for any of this to be meant toward you Alvin and sorry you may have taken it that way. Just believe the right info needs to be out there and the reason for doing the changes or at least be aware of what's done might also require something "else" to be done

[SiriusC1024]

I appreciate the details. Never considered how injector scaling for actual injectors that require scaling would break the model. Good info.

A simple guy like me says, "If the torque model didn't matter it wouldn't be part of the tune."

[Alvin]

So lets throw two scenarios in for explanation.

First off we have individual A - he's running a cammed motor with a blower and decides he needs injectors - he plans it out and gets injectors that fit his flow rate table via normal scaling - if it needs to be scaled at all to begin with and has to add air in everywhere including the idle and cruise zones of the MAF curve, hitting regular cyl air levels and even higher with the blower installed (one would assume no torque model editing would be needed other than the idle area technically and it would survive - right?)

Now let's throw in individual B - he's running a cammed motor, but has plans to install a MONSTER blower and run ethanol down the road, so he think's he's doing what's right and gets the biggest injectors he can but he doesn't want to necessarily spend the money "as things are way overpriced now" and he gets some "not so great brand xer's". Now the not so great brand xer's have injector data, so we have something going there, but due to their size and the ecm's limits we have to do a 30% or 40% scaling. What do we know that this does to the cylinder airmass level's??? Why do we scale the timing table if it's doing nothing??? Starting to put 2 and 2 together now

Now lets throw in the next part of the equation - brand xer's don't fit the flow rate table as we've discussed and requires us to pull air out of the idle and cruise areas of the MAF curve - this is on top of the scaling we've already done. If you didn't see the point before - you should now!!! So, we now have cylinder airmass levels that are lower. A MAF curve that is lower and you don't see a point in "maybe" needing to increase the torque model slightly if not more so on the MAF side and then in the lower regions of the map side??? If you don't by here, I can't help explain it much better because these are the two main extremes you or anyone might see.

Forgive me.. This is a lot of reading.. More than I have time for but did you not write examples were the airflow models are off for some reason or another an required torque edits to get back in line?

[GHuggins]

I can see where you would interpret it that way if you were only reading what you wanted to with blinders on as it was clearly stated injectors with data as it was meant to show where the injectors once scaled required fuel to be removed via the airflow models which in turn changed the torque output - this happens a lot even with good injectors. It was also to show where you scale and change the cylinder airmass readings which can further throw it off - a lot of things can actually cause this not just limited to injectors, but anything that hits lower airmass cells... The injector example was just the extreme I used to illustrate it

[Alvin]

Yes. If your airflow models are not correct because you are fudging injector data I can see how you would then have improper torque.

In turn.. if the airflow model is correct. Your torque will fall in line.

[Alex14SS]

Ive put 20% in Virtual Torque and I can feel the car jump more & I've done this to 4 camaros now, no problems with the transmission at all.

[GHuggins]

Yes, I just finished fixing another big cam ls3 that was having power cut issues only in 6th gear because of the torque model and it had the correct injector data and fully dialed in air models.

Alex, your transmissions should last longer increasing it as they'll hold better

[Alvin]

Ive put 20% in Virtual Torque and I can feel the car jump more & I've done this to 4 camaros now, no problems with the transmission at all.

In another thread you talk about your cammed car hasn't had any VVE tuning. If the airflow models are correct the transmission will fall into place.

I don't recommend adding an arbitrary amount of torque to the tables but others here do. The same thing can be accomplished I think properly by getting the airflow models correct. Other things will fall in line too. Good luck!

[smokeshow]

The torque model functionality is independent of the source of the airflow...so long as it is present and accurate. MAF, VVE... torque features operate all the same.

[Alvin]

Right..

And changing torque will move you to different shift pressures/shift time, etc.

BUT.

Having the airflow models correct is the absolute first step. The torque models will fall in line. And where you need more hold, shift firmness, or whatever there is absolutely nothing stopping you from changing the trans tune at that reported torque level. To say that TORQUE must be tuned.. it just isn't right. You can either skew your reported torque to put you in a harder shift/hold or you can change the trans tune.


So far we've heard in this thread that scaling injectors requires a torque edit. It doesn't. I showed cutting the injector flow rate in half does not change reported torque. Then we get a big reply saying well if we scale the injectors with no data we need to skew torque (well, of course, airflow model is out the window with bad data). We've heard that heavy vehicles need the torque tables adjusted when having a heavy vehicle has no bearing on how much torque the engine produces. Then we get vague warnings that we are going to burn up transmissions cause we are not modifying the torque model... which isn't the case at all either.

[smokeshow]

Yes, you must know airflow to know torque. That bit seems obvious, but I suppose it's worth clarifying. Torque models won't necessarily fall in line though... For sensor changes, like a cold air intake, yes. But for hardware that affects torque capacity, like a camshaft...airflow =/= torque as it exists in the OEM torque model.

[GHuggins]

Once again - you need to go back and actually read my post Alvin. I've clarified this over and over again. We are not modifying the torque model for shifts. WE ARE MODIFYING it for HOLD PRESSURE. AND to Clarify this once again - IN My above post - Injectors WERE correctly put into the tunes.

Why does the OE then change the torque model? Why is the torque model there in the first place? What does the torque model control?

Changing the tune changes this stuff. Just because air or rather "fueling" is correct, doesn't mean the torque model is also correct - PERIOD..... There is a lot of forgiveness designed into it, but regardless...

AS Smoke STATED - ANYTHING that is mechanically changed - thus CAN affect the torque model... This goes down to something as simple as a TB making the engine cruise at a different pedal position changing where the airmass rides... Usually MAF scaling will help with minor things like this, but it will still shift where it's reporting from.

Also once again - you never posted a driving log for the scaled injectors with the air models dialed back in for the scaling

[SiriusC1024]

Yes, you must know airflow to know torque. That bit seems obvious, but I suppose it's worth clarifying. Torque models won't necessarily fall in line though... For sensor changes, like a cold air intake, yes. But for hardware that affects torque capacity, like a camshaft...airflow =/= torque as it exists in the OEM torque model.

You, uh, you wouldn't be referring to a camshaft's effect on torque due to DCR would you?