Importance on Gen4 Virtual Torque?

[C6_Will]

I have been tuning for a while but have never personally knew a true way to go about modifying the Virtual Torque tables on gen4 stuff. Personally I just increase the bottom line until I see some numbers I think the vehicle would roughly make on a dyno in that timing area, then interpolate top to bottom. Seems to work ok most of the time. I?ve heard from some tuners say there is no need to modify these tables on gen4 stuff and I?ve heard some say they?re a must. Just trying to see what y?all think and maybe some of your ways to get new data for the table?s based on mods. Thanks I?m advance.

[SiriusC1024]

Accuracy matters there for torque management. That includes torque truncation for shifts and max torque converter input. Also plays a role in traction control.

[sgod1100]

I've got an M6 cts-v and I've never touched virtual torque. Is it pointless to alter it when you have a manual trans?

[SiriusC1024]

You'd still need it for TC if that matters.

Remember also that a lot of the controls are torque-based. Anything in the torque management tab. Anything where the values for a table/menu are lb-ft. Look around. Evaluate their importance.

[sgod1100]

You'd still need it for TC if that matters.

Remember also that a lot of the controls are torque-based. Anything in the torque management tab. Anything where the values for a table/menu are lb-ft. Look around. Evaluate their importance.

Gotcha, thanks. I have all that shit turned off

[blindsquirrel]

These are torque-based controllers. They calculate everything based on torque, not airflow like the older ones. And it only knows how much torque it's making from what you've told it it makes at a given point.

[Alvin]

Not very important on GEN 4 IMHO

[SiriusC1024]

Yes, not hugely important. Tuning torque calcs on Gen 4 is putting on the finishing touches - necessary for the things mentioned previously.

Changes to torque are proportional to changes in volumetric efficiency. Spark advance has it's effect (MBT), but it's smaller in comparison. Mainly it's volumetric efficiency, so adjust based on changes to VVE.

[07GTS]

ive only see some need if u have a camshaft u can get the idle torque back to the factory range so the throttle follower and idle area is a bit nicer to control

[GHuggins]

Super important on scaled injectors especially if you want an auto to last. Manuals - mainly just idle areas, but it can play with throttle and timing off idle as well. Those that say it's not necessary usually don't live around mountains where it's very easy to make an auto slip especially when you've added a couple hundred hp pulling steep grades in higher gears than you used to.

Just keep in mind the values in the tables aren't accurate to begin with. You need to increase them by roughly how much torque you've added percentage wise at those new air and map levels. There are multipliers playing into things that you can't see plus the EQ ratio ones that you can see.

[C6_Will]

Super important on scaled injectors especially if you want an auto to last. Manuals - mainly just idle areas, but it can play with throttle and timing off idle as well. Those that say it's not necessary usually don't live around mountains where it's very easy to make an auto slip especially when you've added a couple hundred hp pulling steep grades in higher gears than you used to.

Just keep in mind the values in the tables aren't accurate to begin with. You need to increase them by roughly how much torque you've added percentage wise at those new air and map levels. There are multipliers playing into things that you can't see plus the EQ ratio ones that you can see.

The car that actually made me post this question is a buddy of mines 12 model grand sport with A&A kit and 6l80. We installed a flex fuel sensor and a set of fic1000s in it so I had to scale the injectors threw the stoich. The tune he bought the car with, the torque tables had never been touched. Do you have a somewhat method on getting these tables closer to real life or do you just ball park most the areas off experience?

[Alvin]

I've never had a GEN 4 transmission act any differently after scaling injectors, nor have I had the idle do anything odd.

I'd say most issues people are trying to fix with virtual torque go away when the airflow model is really dialed in independently. If your' trying to up a 6L's shift firmness with pressure (not the right way) you might need to make torque adjustments to get it back right again.

[SiriusC1024]

The car that actually made me post this question is a buddy of mines 12 model grand sport with A&A kit and 6l80. We installed a flex fuel sensor and a set of fic1000s in it so I had to scale the injectors threw the stoich. The tune he bought the car with, the torque tables had never been touched. Do you have a somewhat method on getting these tables closer to real life or do you just ball park most the areas off experience?

Yes, not hugely important. Tuning torque calcs on Gen 4 is putting on the finishing touches - necessary for the things mentioned previously.

Changes to torque are proportional to changes in volumetric efficiency. Spark advance has it's effect (MBT), but it's smaller in comparison. Mainly it's volumetric efficiency, so adjust based on changes to VVE.

[GHuggins]

I've never had a GEN 4 transmission act any differently after scaling injectors, nor have I had the idle do anything odd.

I'd say most issues people are trying to fix with virtual torque go away when the airflow model is really dialed in independently. If your' trying to up a 6L's shift firmness with pressure (not the right way) you might need to make torque adjustments to get it back right again.

I've had 2 different customers in the last 3 months alone have burnt up transmissions because of injector data - of course the airflow models weren't dialed in fully either - maf only tunes, but either way... Also it has nothing to do with shift firmness - even though it will effect it - it has to do with line or "hold" pressure... The transmissions ability to "hold" a gear once it's in it - especially pulling steep grades or loads behind the vehicle You honestly may never even notice it on flat ground. Don't get me wrong either - I've run stock torque models in "vehicles" that weigh 14000 lbs empty, but factory already set "those" particular torque models up for that "planned" weight and they weren't running any sort of injector mods. I left the torque models stock in them to get them to downshift with any sort of throttle application on the map sides then increased the airmass sides slightly for the added line pressure, but again those were pretty close from factory.

I adjust solely off of percentage of torque added. Transmissions hold up better. Idle areas are done to obtain idle timing and to get idle control back to stock levels. You have to watch out with injector scaling because of light throttle - it can actually start to hit negative areas in the torque models due to the different ignition timing levels. Whole tune needs to work together - as pointed out by everyone on here...

[GHuggins]

Originally Posted by SiriusC1024Yes, not hugely important. Tuning torque calcs on Gen 4 is putting on the finishing touches - necessary for the things mentioned previously.


Changes to torque are proportional to changes in volumetric efficiency. Spark advance has it's effect (MBT), but it's smaller in comparison. Mainly it's volumetric efficiency, so adjust based on changes to VVE.

This actually works really really good on the map side of the torque model - just don't recommend it as much on the airmass side...

[SiriusC1024]

This actually works really really good on the map side of the torque model - just don't recommend it as much on the airmass side...

Why not on the airmass side?

[GHuggins]

Hard to explain and just going off of experience. Airmass side is based off of MAF and your just going by the added or subtracted torque - a lot of the time just the added airflow will make up for a stock torque model for example on the MAF side and is another reason why injector scaling can effect things - don't think it does take an ecm with the necessary lb/hr limit and do a half inj flow rate double stoich scaling and then put the injector data in correctly if you're able to - MAF curves will be completely different even though they shouldn't be - just like if the injector data was pefect then all you should have to do is plug in the new data and fueling would stay the same as before - right? Nothing ever works that way... VE is map based, so your map torque model tables follow the same shape as your Ve table even from factory so you can directly apply those corrections made to it. The MAF and power curves are still linear and smooth or at least they should be so that side of the model should just be adjusted off of the added torque when need be - you can use delivered torque before and after mods for best adjustments. Fifth gens reveal a lot more on the torque model side of things and how the ecm will use them for throttle and spark control. If you're good on the fifth gens then you can apply those same philosophies to the 4th gens.

You and Alvin are both correct in the fact that the added airflow has already increased the reported torque - as long as everything is dialed in correctly - this needs to be considered when making adjustments... Again if you have any before and after logs really help to keep things right... I use stock idle logs for making idle adjustments all the time - you can get timing and control right back where it needs to be fairly quickly.

[SiriusC1024]

Oh duh I see what you mean. Yes, I was referring specifically to MAP as well. The VVE tables are based on that.

[Alvin]

I don't mess with Gen 4 torque and don't have burnt up transmissions following me around.

Hell just swapped a blower on a box truck one of my race car customers has. We swapped the blower because of the mileage. Its somewhere north of 300k miles.. The trans is still doing fine. Hes got two of these actually.

To say or hint you need to modify gen 4 torque stuff or else your going to have trans issues is just not correct.

[SiriusC1024]

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

Accurate torque would be beneficial to truncation on shifts and torque converter lockup wouldn't you say? As far as transmissions burning up maybe there was gear hunting/going in and out of lockup on these towing vehicles. Same reason it's smart to disable overdrive while in the mountains (on the pos late 90's-early 00's Ford transmissions anyway).