Please take a look at tune/log 5.3L mild cam

[6.0_VHO]

I need help with a tune on 2006 Z71 with 4.10's

specs are:
5.3 mild cam, LT's and high flow cats, ported TB, 8.1 truck injectors, CAI
Comp cam specs out at 202/212 .507/.500 with 1.7" rockers and 116 LSA, 1.8"rockers installed.

adjusted scalar, VE and MAF tuned then adjusted PE and spark and began WOT tuning with LM2.

I have tuned a few 5.3's some stock manifold and some shorty headers with stock cats that feel much stronger down low than this truck does.

1. Is something missing in the tune or is it something else (not enough backpressure?) ?

At WOT, it is a dog until >3000 rpm then it pulls strong. I went to 31 advance with 12.9 AFR with no KR. It made a little better power at 27 degrees total and woke up low rpm PE with lower timing but it kinda flatlines in third. I tried adding and pulling timing and +/- PE AFR but it doesnt respond much better.
I am stuck and don't know where to go from here, please point me in the right direction.

[6.0_VHO]

open my conf file and look at the cylinder air on the graph. Does that look too low? I tried changing spark and PE ration to bring that up but didnt get much.

I just need a sanity check if everything looks ok or call me out on something I need to work on

[6.0_VHO]

wow, 55 reads and no help!?!

[axekick]

I think it might need to go into PE a little sooner but thats just me. Plus in my opinion it shifts too soon, but its hard for me to tell cause I have 3:43 gears so yours might be good. I don't know how you can run so much timing. I keep pulling timing from mine and still getting small amounts of KR. I'm running High octane too. Anyway, from just looking at it it looks like a decent tune. Did you put injector data from a truck with an 8.1 in those charts?

[6.0_VHO]

i copied:
Offset vs. Volts vs. VAC
Flow Rate vs. KPA
Short Pulse Adder
Min Injector Pulse
Default Injector Pulse
...from an '06 8.1L then retuned VE and MAF and zeroed out the AFR Spark Correction table to command timing from the High Octane Table only. I increased it by 2 till I got to 31 and never saw any KR but wasn't making any more power so backed it down to 27
I read different things about retarding a little bit at peak torque and +1-2 above and below there, just not too sure because it kept taking timing and wansnt making any more power. I played with the AFR a little but didn't see much difference. Can I use the Cylinder Air Mass as an indication for improvements since I am not using a dyno?

[6.0_VHO]

any ideas?

[axekick]

I have heard that these trucks really need a higher stall when changing cams and I think that's why. I know that the cam you're working with isn't huge but with the 1.8 rockers I bet it shifts the power curve up quite a bit. I don't know much about cam specs but I'm just going off what I've heard from a lot of truck guys.

[6.0_VHO]

he's at the tranny shop now getting rebuilt and a 2300 stall.
are these(post #5) the right tables to change when swapping to 8.1L truck injectors?

[axekick]

I've never changed injectors so I haven't had to change any of those tables but I believe those are the right ones. If you got the info from a truck that had those injectors then you should be safe. Does it respond well to changes in commanded AFR? If it does then your injector values must be good.

I bet that stall will be just what you need to get off the line better. My Tahoe is a slug off the line too. Its a 4X4 with 3.42 gears and I'm seriously considering putting some 4.11 or even 4.56 gears in. I don't think you can get a whole lot of low end torque out of the tune. If anyone knows anything that does I'd like to know it as well.

[6.0_VHO]

it seems like it takes a little longer to settle in on a commanded AFR than before the injector swap and the idle swings a little. I increased the PE enrichment rate a little but I wasnt sure if those I had to swap all those tables or just the Flow Rate vs. KPA

[Brandon_]

I have almost the same cam 202/212 550 lift and 116 LS.. Ilmy ve table is lower than stock across the board.
Did you have any luck sorting this out?

[anniversaryss]

Tune and log would help tremendously.

[Brandon_]

Here is my most recent log and tune.. Like I said it seems strange that my VE and MAF is well below factory levels. I realize this is a mild cam and my VE table isn't perfect, but still...