Correct IFR tables for LS3/LS7 injectors in Gen III

[eficalibrator]

Guys, these spreadsheets are wrong. Do not use linear interpolation on non-linear data.

...If you're going to post some tools publicly, please make sure you understand the underlying math and physics, and not just take blind stabs in the dark with primitive mathematical tools.

As a point of order, let's start by pointing out these are not to be confused with the data I've released for the FRPP Bosch and Siemens injectors. The values I include with my DVD (along with instructions for properly applying said data) are based on actual mass vs. time and voltage as derived from Ford SciLab data.

...Or are you speaking in terms like Greg Banish who believes ONLY FULL OEM calibration will work? The masses neither understand nor can afford to do OEM style testing, that's why we meet on forums to share what we find out. Don't get me wrong I would love to have everything 100% correct...

OEM testing isn't the ONLY way, but you need a far more complete workup than the typical ASNU bench data most of the aftermarket thinks they can get away with. I'm working with companies like FAST and Continental to make good, complete data more commonplace in the performance aftermarket.

As to Greg...well, let's just say I blame him directly for giving people the horrible idea that you can use the linear interpolation on every table, as he does it repeatedly on his DVD, and it's absolutely wrong.

Marcin, I guess I missed where I endorsed "linear interpolation on every table." If one watches the DVD carefully, I only encourage linear interpolation across small sections of the offset table. The raw data points I'm working between are VERY nonlinear, but limited to the resolution provided by Ford.

The short pulse adjust table is linear as a result of the source of the data. Ford themselves model the nonlinear flow region with a single secondary slope below the breakpoint combined with a shifted offset. I think we can all agree that Ford has got close enough injector control to use this model to achieve ULEV emissions standards on many vehicles, a target much more stringent than the performance aftermarket dreams of today. Sure, we could be a little bit more robust with a full workup of mass vs time in the transitional area, but we're already well beyond the point of diminishing returns for fuel mass precision here.

At the end of this, there's a time and a place for linear interpolation. I started with as accurate of a non-linear source as possible then interpolated to fit the various GM breakpoints near that. Lot of 3rd parties have already confirmed that the resulting values were so much more accurate than what they've been struggling with that all the remaining calibration work really was that much easier.

By all means, start a fresh thread if you wish to discuss in more detail. It wouldn't be that difficult to convert LS3/7 injector data to LS1 breakpoints with a reasonable amount of accuracy using the same strategy.

[redhardsupra]

Two spreadsheets,
one for LS3:
http://www.marcintology.com/tuning/L...LS3%20Data.xls

...and one for LS9:
http://www.marcintology.com/tuning/L...LS9%20Data.xls

Here's some pics of how closely now the fitted surfaces are to the original data (LS3):


the wireframe is the original LS3/9 data, the colored surface is the fitted LS1 style surface.

...and the same thing for LS9:



and for the final show, Short Pulse Adders for LS3:



...and LS9:



Please take a look at the spreadsheets, they should be correct, but you never know, I might've copied'n'pasted something wrong.

[WHYTRYZ06]

marcin,

wow just wow good work... joe is finishing up his as we speak

[joecar]

Marcin, good job......what did you use to plot those...?

[WHYTRYZ06]

Marcin, good job......what did you use to plot those...?

joe is urs gonna be the same? i still wanna see what u come up with

[joecar]

joe is urs gonna be the same? i still wanna see what u come up with

I'm still working on it.

[WHYTRYZ06]

I'm still working on it.

okie dokie...

[redhardsupra]

Marcin, good job......what did you use to plot those...?

Matlab's surf and mesh functions for 3d stuff, line for 2d stuff. The interpolation itself is done with splines.

[mr.prick]

I'd like to know why 2 different vehicles with the same fuel injectors have different offsets & IFR.

2002 Camaro Coupe Manual 5.7 Litre LS1 12212156
2002 Corvette Coupe Manual 5.7 Litre LS1 12212156

[redhardsupra]

I'd like to know why 2 different vehicles with the same fuel injectors have different offsets & IFR.

2002 Camaro Coupe Manual 5.7 Litre LS1 12212156
2002 Corvette Coupe Manual 5.7 Litre LS1 12212156

they might not be truly stock tunes. different OS's might reflect different hardware, or just an improved calibration.
that's a Greg question if I ever seen one... Maestro?