2 Attachment(s)
E92 - Sluggish Throttle Response?
Hey guys, hoping this is an easy one for somebody out there. I just purchased a new to me '15 Silverado 1500 with the 5.3L and 6L80E transmission. It is pretty low mileage and runs well especially at higher speeds but it just feels very sluggish in terms of throttle response when taking off from a dead stop. I know on my 2011 Sierra which has the E38 ECM I found that the "Throttle Area Increase Rate" table had throttle response in first gear nerfed below 2250 RPM's. Setting those values to 100 made a ton of difference in first gear throttle response. I was hoping to find a similar table on the E92 ECM but was dismayed to find that this table simply does not exist.
Now before anybody tells me to do a search, I HAVE. I found that the answer to my question may lie in the "Driver Demand" tab, specifically the "Torque Request Rate Limits" setting along with a few corresponding tables. I first saw that the "Increasing Rate Limit" is enabled and thought I might have hit pay dirt with the "Immediate Normal" and "Immediate Tap" tables. I opened up the tables expecting to find some comically low values for first gear only to find that the values are the same for every gear in both tables. Every single value is set to 6041.9. The "Predicted Normal" and "Predicted Tap" tables have different values for different gears but I'm not sure if I'm barking up the right tree or not.
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So several questions I'm hoping somebody can explain in fairly plain English. I'm not an idiot but I'm not an expert.
1. What is the difference between "Immediate" and "Predicted" tables?
2. The Y axis of the table is obviously the gear, the values themselves are ft-lbs, what does the X axis represent? I know the label is "Delta Torque" and delta is a change or rate of change. I just don't really understand what that means vs the actual values, both the axis values in ft-lbs and the table values in ft-lbs seems odd to me. I'm sure it makes sense with a good explanation, I am just lacking that explanation.
3. Does the fact that the "Immediate" tables have maximum values mean that there is no restriction or do the predicted tables play into it somehow?
I feel like I could also potentially disable the whole concept and get instant throttle response by just setting the "Increasing Rate Limit" flag to Disabled, but then again maybe not because the mouse over description makes it sound like this only comes into play when the vehicle is stationary? Yes I know I can just start changing values and see what happens but I generally like to try and make somewhat informed changes. Also I just bought the truck and have not bought a license for this VIN yet. I don't have any other immediate need to make changes so I might save the money for a bit if there is no help in this area.
On a related note, my 2011 has 3.42 gears and my 2015 has 3.08's so I am well aware that is going to make it feel somewhat sluggish regardless. Thanks
