7427 upgrade tuning help understanding

[typhoonss92]

copcar injectors are 83lb @ 15psi. I have mine set at 22 when it is cooler our and goes down to almost 20 when hot, I live in Fl.
So with all the different places/excel sheets to calculate I should be 96-100lb per injector. I think I need to go a touch higher because I am maxing out the VE table in a few places but the problem for me is the red spring I have for the fpr maxes out at 22 and I would like to be able to got to 23 or 24 but can't find a spring, may just go external fpr unless anyone knows where to get a spring that has a range of lets say 20-26ish psi.

[stew86MCSS396]

Didn't know those existed. Got a part number for those and perhaps a link to where I might be able to acquire some. thanx!

[typhoonss92]

ebay search "tbi cop car injector". 17084327 - Yellow / Brown - 5.7L / 350 Police Package 76 Lbs/ Hr @ 12.5 PSI, 83 Lbs/Hr @ 15 PSI

[dave w]

ebay search "tbi cop car injector". 17084327 - Yellow / Brown - 5.7L / 350 Police Package 76 Lbs/ Hr @ 12.5 PSI, 83 Lbs/Hr @ 15 PSI

Based on the information in this link: http://www.gearhead-efi.com/Fuel-Inj...d-part-numbers ... the 17084327 injector has a factory rated flow of 65 PPH

dave w

[typhoonss92]

https://www.ebay.com/itm/SET-of-TWO-...UAAOSw8A1ajG~e
not sure how true their test is but here is what I got about 2 years ago. What is the psi for 65# from GM. this may be where my calculations are off for fuel and why I may still need a few more psi.

Dave I know you played with springs for the fpr years ago, do you know of one that will work to get me around 22-25psi, the red one they sell only gets me to 22 and I consistently keep maxing out my VE table up high map.

I also set the closed loop as you said and had 2 datalogs today one to the parts store with a little getting on it and the second cruise and highway. I have a little up and down rpm in park with the a/c off with in on don't get it. I think it started when I used the simulated nbo2 from the wbo2 and I am going to swap it back to the 3 wire I originally had setup to see if that makes a difference. Also the blm is no where near the wbo2 readings it is always rich. With the wbo2 being 28in down stream I would need to make changes to the o2 settings but not sure which ones or what to possibly change them to. If you have time any thoughts

[stew86MCSS396]

Didn't peak at this ^^^bin but the previous one target AFR was set at 14.1:1, would that be cause for lower than 128 BLMs??? Sorta read that's something you would do for E10 tuning.

Yeah...I chased my tail on a tune that Holley told me the size of the injectors but kept seeing injectors going static. Decided to run factory known sized injectors and the tune is way better. Think attributed to Holley rating their stuff at 28 psi while AFPR was set for factory 12.5 psi. Idk what to believe, I'd like to concoct a flow bench and test these Holley ones.

[dave w]

Attached are more spreadsheet screen shots from the same combined data logs previously posted.

Injector Duty Cycle should increase with engine load / engine rpm.

BLM's and WBO2 data are not aligned. Closed Loop WBO2 tuning will have better overall performance!

For a daily driver 16197427, I like tuning with stock injectors, stock spring, with stock injector parameters. Perhaps, using higher flowing 16197427 7.4 liter injectors, stock spring, with 7.4 liter injector parameters is an option to think about?

Spark Advance is challenging, perhaps an experiment with minimum temperature for Knock Retard set to 151 Celsius will provide valuable data?

dave w

[dave w]

Attached are more spreadsheet screen shots from the same combined data logs previously posted.

Injector Duty Cycle should increase with engine load / engine rpm.

BLM's and WBO2 data are not aligned. Closed Loop WBO2 tuning will have better overall performance!

For a daily driver 16197427, I like tuning with stock injectors, stock spring, with stock injector parameters. Perhaps, using higher flowing 16197427 7.4 liter injectors, stock spring, with 7.4 liter injector parameters is an option to think about?

Spark Advance is challenging, perhaps an experiment with minimum temperature for Knock Retard set to 151 Celsius will provide valuable data?

dave w

I tune a daily driver 16197427 with two Oxygen Sensors, the factory O2 sensor and the WBO2. I do not use simulated NBO2 data.

I tune a daily driver 16197427 with factory default AFR fuel ratios.

dave w

[Fast355]

Attached are more spreadsheet screen shots from the same combined data logs previously posted.

Injector Duty Cycle should increase with engine load / engine rpm.

BLM's and WBO2 data are not aligned. Closed Loop WBO2 tuning will have better overall performance!

For a daily driver 16197427, I like tuning with stock injectors, stock spring, with stock injector parameters. Perhaps, using higher flowing 16197427 7.4 liter injectors, stock spring, with 7.4 liter injector parameters is an option to think about?

Spark Advance is challenging, perhaps an experiment with minimum temperature for Knock Retard set to 151 Celsius will provide valuable data?

dave w

Anything with a 7.4 and the 7427 used a 46 lb/hr injector @ 28 psi. Barely enough fuel to support a stock 5.7 Vortec much less anything making any power at all.

I use 14.1 stoich on our E10 here. The fuel trims always seem to fall into line more easily as do the WOT air/fuel. 12:1 around peak torque and lean out to about 12.6:1 at higher rpm.

[PlayingWithTBI]

copcar injectors are 83lb @ 15psi. I have mine set at 22 when it is cooler our and goes down to almost 20 when hot, I live in Fl.
So with all the different places/excel sheets to calculate I should be 96-100lb per injector. I think I need to go a touch higher because I am maxing out the VE table in a few places but the problem for me is the red spring I have for the fpr maxes out at 22 and I would like to be able to got to 23 or 24 but can't find a spring, may just go external fpr unless anyone knows where to get a spring that has a range of lets say 20-26ish psi.

I got this spring from ebay, and running @ 28PSI with the adjuster barely turned in. I think it's from a 95-96 7.4L, so this may not help unless you go higher than you mentioned.
https://www.ebay.com/itm/GM-TBI-28ps...97.m4902.l9144