Virgin To The Tuning World....LY6 in place of LM7 ....Needing experienced assistance

[TheRagged1]

so like the title says... first time tuning anything...I own a shop and do anything automotive so im familiar with the logistics of mostly everything, but tuning has me a little overwhelmed.

What i have going is an 01 tahoe that had a junk 5.3l (LM7) and i put an LY6 out of an 08 in it ... it runs pretty decent but i know theres massive amounts of adjusting for improvement.. Im just not experienced/confident enough to know what to adjust without potentially hindering anything

it has the stock trans (4l60e)/torque converter, t-case, tire size, O2 sensors, MAF, valve train, ECU, resonant knock sensors (with aftermarket brackets)...all stock per vehicle application..

stock LY6 parts consist of: original intake/injectors #12580681, MAP sensor


other upgrades when built was a ls3 cam #12623063 non VVT
Dur.@ .050in. 204/211
Lift - .551 / .552

Lingerfelter conversion module

92mm throttle body ...cable driven

no egr with LY6 ...im sure your aware

just really looking for pointers on where to go from the little bit ive changed / or if someone can build a base tune and instruct me where to go from there... ill pay.. if youre not having me pay your mortgage that is... have original stock file for both the LM7 and LY6 vehicles if that helps at all... tell me how dumb i am and what ive done wrong ..not gonna hurt my feelings..i get it.... just trying to learn and get this running better where its happier.. this is the current tune file im with and changed very little. just a little obvious things (to me)...... any help/ insight would be greatly appreciated

Thanks, Andrew

[blindsquirrel]

What fuel system is it - LY6 returnless rail, returnless fuel system? What's the rail pressure as measured with a gauge at key-on?

[TheRagged1]

the vehicle has a return fuel system that i had to use the corvette regulator/filter to adapt to the returnless fuel rail. the hiflow fuel pump i put in it reads 75 psi at the rail at all times.. key on / key on & engine running

[5FDP]

Toss the corvette filter regulator in the garbage or on the shelf, you can't use them with high flow fuel pumps.

75psi is way too high, you need to regulate the fuel pressure down to 58psi. And as I said in the other thread get the rest of the injector data for those injectors.

[04silverado6.0]

Here is your injector data at least. At 58psi.

[blindsquirrel]

the vehicle has a return fuel system that i had to use the corvette regulator/filter to adapt to the returnless fuel rail. the hiflow fuel pump i put in it reads 75 psi at the rail at all times.. key on / key on & engine running

That is not a return-style fuel system. 'Return-style' is shorthand for 'referenced', meaning the fuel pressure is variable because of a vacuum reference hose, NOT whether it had a separate fuel return hose back to the tank. You have a 'returnless' system that runs the same fuel pressure at all times no matter what the engine is doing.

[blindsquirrel]

Here is your injector data at least. At 58psi.

That does not match what's in an early E38 128-640 kPa file -
2008 Silverado 1GCEC19J28Z240561 E38 5.3 LY5 4L60 1214830015.hpt

Fun fact: these injectors were used in E40s, early E38s (128-640 kPa scale), late E38s (128-768 kPa scale), and also early E67s ('07-'08 Trailblazers et al) and late E67s ('09 V8 Trailblazers).

The E40 tables are very very similar to the Gen 3s, it's mostly a straight copy-paste between them, filling in a few blanks, and using the spreadsheet to convert the Short Pulse Adder table (spreadsheet works on all year Gen 4 Short Pulse Adder tables, those are all the same regardless of early or late table style).

[04silverado6.0]

I believe I got the data from a tbss but don't remember the year. Maybe I should double check my work. I have definitely used this with success. Edit: It was a 2008 TBSS.

[blindsquirrel]

Like I said, if you use a 2006 E40 file it's mostly just copy-paste. It has the same 0-80 kPa VAC IFR & Offset tables already.

12580681 and 19421333 are the same injector with the same specs, old vs. new/current part number.