ToxicWS6

so ive finally got my car back on the road and using same tune i had dialed in great, just on a 6.0l instead of a 5.3L, im starting to do some clean up tuning, one of the first things i noticed though was it was correcting from -11 to -18 (green) ish through most my area on the ve table, mainly lower rpms and idle as im breaking my clutch in atm, which to me is its too rich atm, and for being a 6.0l instead of 5.3 i thought to would be lean if anything, well with that being said i checked my WB readings and they all read pretty good, 14.8-15.2 in the idle/cruise area.

should i trust my WB readings and be done with that area or should i try tuning the ve table in using fuel trims again?

also noticed the 1 or 2 times ive hit boost it was reading 10.4-10.7 instead of the commanded 11.8 i use to get.

only thought is the new fuel system (-8 lines and FAST fuel rails) instead of stock everything but injectors, is causing it to dump more fuel on this tune cause it has more of a supply then before

lq4, brute speed blower cam, ls6 intake, 60lb seimens injectors, -8 feed lines, 340lph pump, Fast rails, Fuel lab regulator

jimmyblue

iTrader: (11)

I don't have a beef with negative trimming especially
on a boosted motor, where you sure don't want a lean
surprise on transient throttle. Let the short trims take
that out, starting from a place of safety, is OK by me.

Is the displacement value trued up for the new block?

If you reused the heads, intake, exhaust I'd expect the
6.0's VE curve to fade early compared to a 5.3 drawing
through the same plumbing, and then you'd overestimate
airflow and end up fueled rich. But changing the delivery
system can also provide you more fuel pressure at the
big end, than maybe you had with the prior setup.

I'd say you're just in for a full redo, having changed so
many aspects at once.

ToxicWS6

at this point yeah, im pretty much going back through and redoing a lot, for the 5.3L i use to have it was an lm7 with 243 heads so 9:1CR, the lq4/6.0 is 317 heads at 9.5:1CR, rest is the same

i actually got the mid to low range a lot cleaner pretty quick but still rich is, -5 to -9, still shows up as 15.1-15.3 ish though on WB (its been awhile but green negative number means take fuel out its rich, but yet the WB is reading lean?)

and biggest thing stumping me now is for boost enrichment, its commanded 1.26 which should be 11.65 (14.68/1.26 = 11.6507) and im still getting pig rich low 10s (10.2-10.8)

this just thought of though so may or may not make sense.. lol, if im hitting 165kp say but at %67 throttle, would it have that pressure to dump fuel but not have the full 100% throttle of air flow to match it?

i dont remember ever having this issue before though, and i pretty much thought if i commanded 1.26 Boost enrichment it would trump everything else and make it a 11.6 afr when in boost, weather its a little bit of air or a lot

that all above said i notice my injector values are a lot lower then they use to be, probably where they should be since i have proper rail and lines now but, on a quick pull like ive done they would be maybe 60-70% give or take, now if i boost and hit say 165kpa there at 30-40%

whats the chances of this being a fuel pressure difference between old set up and new? old was stock fbody regulator with 340lph pump and 60# injectors, with a tester on it at idle i was around 70-72psi, new set up is same pump and injectors but with -8 lines, fast rails and fuel labs FPR set at 66-68psi, im thinking of possibly turning up to 72psi see if it helps with issue

eaglegoat

Adding more pressure will not make it run leaner. Are the injector values you have in the tune set up for the 66-68psi your running? I'm betting they are not.

ToxicWS6

Probably not, good call, that being said, would it be better to turn fuel pressure up to where they are tuned for or try to get the data to scale them down to the pressure im at? Which wasnt chosen for any real reason minus thats where it started to idle normal and smooth out

eaglegoat

That's a personal choice. I'm betting you have 4 bar data in the pcm and it was just tuned around (bandaid) that data. If you're running a return system now I'm betting you're not set up for that either.

ToxicWS6

Ok, if i was to do this the right way (which i do ) what would be there first step? Putting fuel pressure to the rated 43.5lbs and putting in the correct values for that?

ToxicWS6

Also ill post tune when i get home and i would like u to nit pick it if u dont mind lol

eaglegoat

GM fuel pressure is 4 bar(58psi). Most injectors are rated at 3 bar(43.5psi). "Right" is subjective. I'd suggest you set your fuel pressure to whatever your data indicates. It's not nessesarily what I'd do, but it's what I suggest you do.
My computer took a dump recently and I'm figuring out what I'm gonna get next. Sorry.

You've got more going on here than just some settings in your tune. You also have a discrepancy on what your wideband is showing and what your trims are showing. That can have lots of different causes.

ToxicWS6

So u would agree the wideband and my trims arnt quite accurate?

LSX Power Tuning

iTrader: (4)

If you're in closed loop you cant use your trims and the wideband at the time. Your trims are going to be correcting your part throttle fueling to 14.7 so your wideband will always be reading really close to that. You can log your trims and then go into open loop and do another log and check again with the wideband and you should get the same numbers or really close to the same.

ToxicWS6

ok ill try that and see how it comes out, thanks!

LSX Power Tuning

iTrader: (4)

Sorry I meant to say you CANT use your wideband and trims at the same time. I corrected the post.