2015 Silverado Virtual Torque Tuning

[Drif10s10]

I have a 2015 silverado 6.2 with a BTR 220 cam and Yank 2800 triple disc. I'm dealing with a stalling issue when coming to a stop sometimes and when im on and off the throttle moving my trailer around the house. Normally the truck will fire back up, but yesterday it went to limp mode and the P16F3 came up.

Is there any tips/tricks to tuning VT with a stalled TC?

I've lowered the VT tables in the idle areas down to where the idle is fairly stable. Its a slow increase from 700 to 800 and then comes back down.

I've been reading and watching everything related to virtual torque, but nothing specifies what to do when tuning with a stall.

If the torque multiplication at 2800 is 2X like the website says, do i need to double the VT table in this area?

The yank is bigger and heavier than the stock. When I let off the gas my TCC slip goes negative 100-200 rpm. I have all of my slip tables set to 0. Could this cause the engine to pull timing and stall out?

[04silverado6.0]

I would start by reducing torque in the idle areas and in the area you are having trouble. Lower values in vt will command more torque to be added to keep the rpm stable. Post tune and log.

[Drif10s10]

VT is lowered by 30ft-lbs in the 500-1000 range.

I had the truck in drive, with the foot brake pressed, gave a little gas then left off when the truck died in the last 30 seconds of the log.7-23-23 COLD START IDLE.hpl MY TRUCK. STOCK VT LOWERED 30 IDLE.hpt

[Drif10s10]

What changes need to be made based on this log. I'm idling lower than the base of 750 set. After 3-5 times of running the engine, the P16F3 code comes back and i have to disconnect the battery to reset the computer.

My torque converter doesn't lock till the trans temp reaches 70 degrees. With the sure cool bypass and the routing of the exhaust, my trans doesnt reach temp till I'm 10 miles down the road. This gets to be very loud at 4am driving to work. Is there a way to lower this?
Attachment 135019
Attachment 135020

[GHuggins]

There is A WHOLE lot more to idle tuning one of these than just modifying the torque tables. First and foremost I would focus on fixing your VE table. That thing is a mess These are the 0 cam setting torque model tables I'm running in one I'm finishing up. I dial all of the models in to the best of my ability - not just the 0 for what it's worth. I would recommend keeping yours at least close to the same starting out for the different cam settings. If you really look at these close you'll notice the map model and even a little of the airmass model follow rather closely to the VE tables new shape. There's a lot in the torque model for throttle opening and closing on both decel and take off and are on the opposite sides of the model with one being slightly lowered and one being slightly raised with spark - hint hint - will aid in throttle response and your problem both, BUT your airflow and fuel models both alike have to be dialed in for all of this to work correctly and then you have the idle and idle spark settings that will also work with all of this. Also keep in mind the cam needs to be locked at 0 and dialed in there then moved to maximum travel and dialed in there for correct VE dial in. Proper VE dial in, proper fuel density table dial in and proper MAF dial in is all needed for proper torque control to even begin to be thought about. I would shape the idle area of the torque model slightly for now to get it to idle right and then revisit it after everything else is done.

Attachment 135029Attachment 135030Attachment 135031Attachment 135032Attachment 135034Attachment 135035

[Drif10s10]

Thanks. I will dive into these areas. I am new to this but want/need to learn. I'm addicted to speed, just don't the financial backing to go as fast as I want. So the more I can do myself, the more I can medicate myself.

The attachments will not open for me. I get an invalid attachment error.

I do have LT4 injectors and HPFP with a lash cap installed. I copied the fuel settings from a stock 2017 corvette z06 file in the tune repository. I did this planning to run e85 and nitrous in the future. I believe I made all of the changes needed. What do I need to look out for to know if I have proper fuel density?

Are you adjusting MAF and VVE at the same time or separate? I've seen both methods being used.

Can you elaborate alittle more on the mess of my VVE table. Is it the ridge at 2500? The sharp peak at 4500? The step ups as the pressure increases? How the graph looks to be interpolated (linear) vs. rounded (humps)? All of the above?

[GHuggins]

See if that isn't better.

LT4 injectors actually stick to their stock density tables fairly well once installed in other vehicles or engines. It should only require minor changes from that standpoint but basically if you want fueling to stay the same at all temps and corresponding rail pressures you have to dial the density table in for it. Otherwise fueling and corresponding torque will never stay the same. I've fixed a lot of cold engine or hot engine operation problems with this table alone.

Since you're not a lt4 from the factory I recommend failing the MAF, locking the cam at 0 and dialing it in that way. Then change the cam to the max degrees you're going to be running and dial in the coefficients for that as shown above. That VE table had +/-3 to 4 trims for different temp errors with the majority of errors staying around +/- 2 percent. I've got a lot of time in that tune though as well as the owner taking the logs.

You can look at your VE table vs the one I posted above or even compare it to a stock and you'll understand what I'm saying. The lower decel / light throttle cruise area is used for returning to idle and when you have those dips and ditches and can cause all sorts of torque mis-calcs on it's own. Goal is to have fueling right, but you can usually tell by the shape if it is or not.

[Drif10s10]

Yes the new attachments are working.

I have noticed that the truck goes into limp mode mainly in the afternoons and that these problems came about in the middle of this heat wave we are having in southern Louisiana.

I see the differences in the VE tables. Since this will be street tuning, what filters can i apply to help with getting good logs?

[nicul15]

Do you find the stock truck injector flow rate alcohol multiplier accurate?

A lot of people set this to 1.0 across the board. I don?t understand why gm would fill this in on the 5.3 like that if it didn?t translate to the lt1

[GHuggins]

Do you find the stock truck injector flow rate alcohol multiplier accurate?

A lot of people set this to 1.0 across the board. I don?t understand why gm would fill this in on the 5.3 like that if it didn?t translate to the lt1

Don't set it to 1, however that would be more accurate than the stock settings. If you don't know how to dial it in copy the one in the SD section and paste that into the MAF multiplier - which is located under the injector flow rate table. I don't know why GM did them that way, but I've never found them to be right. In fact I guess because it's so hard to find non ethanol fuel GM left the 10% set to 1, which is also wrong if you're running non ethanol fuel vs ethanol because 10% ethanol will obviously require a little richer mix - right?

I will say this - once you figure out how to modify the multipliers - they all work the same way in a fifth gen. Also you don't multiply them - you add a set number to them that is calculated from an error - if that helps you any...

[Drif10s10]

I have LT4 injectors and HPFP. I pulled everything over from a 2016 stock Z06. The only tables not matching is my SOI/EOI cranking angle, High Pressure Desired, and my Leading edge angles. I multiplied the stock Y axis by 1.32 for the 32% lobe on the cam.
FUEL COMPARISON-1.pngFUEL COMPARISON-2.jpgFUEL COMPARISON-3.jpg

I only run 93 octane E10 pump gas in the truck. So my stoich is set to 14.1 across the entire table. Once i get a handle on the tuning process, I'll add the ethanol sensor and dive into running E85.

GHuggins - just by you mentioning certain areas to look at is helpful. This gives me a focus area to research. I copied the SD multiplier to the alcohol multiplier under the injector flow rate table. I don't see a MAF multiplier. Is this the correct table to paste it in? I think its funny how people talk about the huge changes in sizes when dealing with engines and all they are referring to is .125" of change. Even the differences in these two multipliers is up to .07500.
ALCOHOL MULTIPLIER.jpg

I've been working on the VVE table. Only up to 4k rpm though. Based on the lower half of the graph vs the upper half, does it look like im heading in the right direction?
VVE CURRENT.jpg

[GHuggins]

Yes that looks a lot better and is the correct location for the MAF alcohol multiplier. Would be nice if they just labeled it that way since that's what it is.

For reference a difference of .07500 is a difference of 75% with the gen V multipliers

[nicul15]

Ghuggins - thanks very helpful. Now moves the fueling the right direction.

Drif10 - a flex 5.3 file shows 1.0x and goes higher as E increases