2010 sierra 5.3 vvt tuning

[04silverado6.0]

Has anyone had any success tuning vvt on the gen 4 5.3? I have searched the forums and most info is for the 6.2. I have made a new vvt table to try tomorrow but do not have a dyno for testing. If anyone has advice or a tune file they will share it would be appreciated. Here is the stock read and the file with the new high baro table.

[04silverado6.0]

I ended up finding a couple more forums after hours of research. Here is what I came up with on the vvt tables.

[That_guy]

Are you trying to tune a stock VVT cam or aftermarket?

[04silverado6.0]

I probably should have given more details, the truck is fully stock.

[verlon]

Calibrating VVT is a delicate thing.
There are two extreme strategies - maximum power and maximum fuel efficiency. Stock calibration combines both and you can see different trends in different rpm/load zones. Maximum power strategy (like you did) will give excellent pedal response but very poor light load fuel efficiency. Maximum power is obtained by maximizing cylinder airmass, it's simple physics. Have you performed a series of WOT pulls to measure airmass vs rpm with small cam retard steps or just took someone else's 'known good tune'? I think second is the case. Easy, convenient, but not reliable - you can reproduce someone else's mistakes.
To get maximum fuel efficiency you have to minimize torque losses - mostly pumping loss. Main factor influencing pumping loss is vacuum, so we have to reduce it. But reducing it to near zero is not a good idea because at this point depressing pedal further will give us absolutely nothing, i.e. we'll get junky pedal response. So limiting vacuum to 15-20 kPa will give us acceptable pedal response and significant pumping loss reduction.

the truck is fully stock.

Why have you changed final drive ratio then?

You've changed [TCM] 5100 - Maximum Line Pressure. For what? Pressure control solenoids are feeded thru AFL (Actuator Feed Limit) valve which limits Feed Pressure to 110PSI. Have you replaced AFL valve or you have some secret considerations doing so?

[Alvin]

There is not a lot to gain in this setup with VVT tuning. GEN 5 stuff stands to benifit in a few cases but typically you can make big changes to VVT on Gen 4 cars and barely make a difference in power.

I wouldn't recommend doing it without a dyno. Often changing the cam timing will give the engine a different sound which people mistake for more or less power. I know that sounds odd.. but been there done that situation.

[04silverado6.0]

I forgot about the gear swap. I was not aware of the AFL in these trans, I have been raising max line pressure and it seems to give some boost in shift feel. I did log and watch airflow and the VVT table I used was not copied. I did copy the idea of my strategy however. This has been a process with multiple edits.

[04silverado6.0]

[TCM] 15580 - Max Line Pressure vs. RPM vs. Gear: Maximum line pressure in each gear in relation to engine speed. This table is below the 110psi limit stock and may be the reason I am seeing a difference.

[verlon]

I wouldn't recommend doing it without a dyno. Often changing the cam timing will give the engine a different sound which people mistake for more or less power.

Tuning cam timing is relatively easy when you choosed your strategy. A dozen of daily driving logs for cruising zone and several WOT pulls for power zone. The rest can be exprapolated and hand-drawed.
VCP Spark is much more difficult to calibrate. Different engine sound is a spark related thing, not cam timing. Changing cam timing you just moving MBT.
I wrote about how it works five years ago and have sent to support all necessary information.
https://forum.hptuners.com/showthrea...Fraction-Model
But HPT team decided to ignore it completely.
VCP Spark can be calibrated universally for all conditions, not only EGR zone as was done stock, but you have no tool to do it.

I forgot about the gear swap. I was not aware of the AFL in these trans, I have been raising max line pressure and it seems to give some boost in shift feel. I did log and watch airflow and the VVT table I used was not copied. I did copy the idea of my strategy however. This has been a process with multiple edits.

Ok, just it looks overretarded at high rpm. Many tuners looks at 2010+ engines with 12* cam @ high rpm and thinks it will do something good on older engines.

[TCM] 15580 - Max Line Pressure vs. RPM vs. Gear: Maximum line pressure in each gear in relation to engine speed. This table is below the 110psi limit stock and may be the reason I am seeing a difference.

You will never hit this stock limit on a healthy trans. Look at NA and SC Corvettes - they have the same values as your stock truck.

[04silverado6.0]

I guess I learn something every day. I have seen people recommend raising line pressure to 3000+Kpa even on stock trans. I haven?t got a chance to upload the last tune for the truck. Overall with 2 days of tuning it is a whole new truck and picked up noticeable power and driveability. It seemed to pick up power with less spark as well.

[Alvin]

Changing valve timing by advancing or retarding the cam will very much cause a audible tone change to the engine that people can mistake for a power gain/loss.

Just think.. if you advancing the cam.. The exhaust is opening sooner, sending more of the power stroke out the tail pipe.. at a higher pressure.... Its going to sound different.

[verlon]

Changing valve timing by advancing or retarding the cam will very much cause a audible tone change to the engine that people can mistake for a power gain/loss.

Just think.. if you advancing the cam.. The exhaust is opening sooner, sending more of the power stroke out the tail pipe.. at a higher pressure.... Its going to sound different.

It is, but retarded spark (relative to higher MBT due to retarded cam) will lead to similar conditions - higher exhaust pressure, but because of higher exhaust gas temp due to efficiency loss. It's like power upshift with spark torque reduction. And this (spark related) sound change is much more noticeable.