Advice:427 supercharged LS9 injector/LS7 MAF

[exploder]

I am just looking for a little guidance here. I have a customer that brought me a 427ci LS7 forged motor and also a A&A Ysi supercharger kit/ LS9 injectors modified for 80lb flow and a LS7 MAF. I have already installed the motor and cranked it up with its old stock tune without the supercharger. It ran fine and everything but it would not run with the LS7 maf plugged in; only with the original (as expected).

What I am trying to decide is whether or not I want to jump straight into just doing a hack job maf after it maxes out or should I just go straight 2 bar. If I use the MAF where and how do I start tuning it? (do I just plug it in and start autoMAF or is there something else that I need to do to make the LS7 card MAF work).

The customer also brought me a set of modified LS9 injectors that are supposed to flow around 80lb/hr. Are there any IFR tables for these injectors or some like them? Or do I just use the IFR spreadsheet and make and educated guess?

I am attaching a copy of the original tune file unmodified by me from the last tuner. I will appreciate any advice on these aspects and was also interested in if I did go SD for the customer if the STFTVEcalculated PID is a good way to go or if there is a new way better than AUTOVE or STFTVEcalculated?

[joecar]

If you can copy his tables into a 12212156 file (F-car if he has cable throttle, Y-car if he has DBW) and get it running the same, then you can jump to COS5 and install a 2 bar MAP sensor.

Regarding LS7 MAF: try adding or subtracting 10% and see if it runs... I don't know how the LS7 MAF table is scaled, but if you can get it running so you can log MAF g/s then you know how to adjust B5001. How much time do you have to play with the MAF...? When you have the LS7 MAF on there, do any DTC's show up...?

Also fix the all of out of range cells, they make the PCM do extra processing.

Send me your email address, I'll email some spreadsheets for LS9 injector tables mapped to LS1 tables.

[odd boy]

Joecar,

please post these files and make them sticky. I am interested too

[joecar]

These are the injector tables from LS3/LS7 and LS9 interpolated to fit the LS1 injector tables (paste-with-labels)...

LS3/LS7: GM calculated B4001 based on rail pressure 58.0 psi.
LS9: GM calculated B4001 based on rail pressure 61.4 psi.

So for LS9 you may want to either run 61.4 psi (if you can) or rebase B4001 for 58 psi.

[Redline Motorsports]

Well here we go again...............the injector data is probably no good with injectors that have been modified from that data point.

How much power to do plan on making? A set of 63.5" (@3 BAR) will support 950 RWHP FI with a rise and rate fuel system.

I don't know what year the processor is but I'm sure you'll hit the limits of the MAF unless you either re-scale the calibration or ditch it for a 2 BAR setup.

You can't just unplug the MAF as it also has the IAT built in. If it doesn't run with the MAF disabled, then the VE is off good.

There are some tutorials available that should get you going.

Howard

[joecar]

Oh, I didn't see "modified" in post #1... sorry, my mis-read... Howard is correct.

[exploder]

We are shooting for around 850whp. The car is an 01 model as far as OS goes currently. I guess I will just have to wait a few more days until I get all of the injectors here and go from there. I am also going to seperate the IAT sensor out from the maf to aid in the 2 bar. Will these injectors IFR tables at least get me close even though they are modified?

[joecar]

The IFR table will have to be rescaled for the new flowrate and for rail pressure.

[Chuck L.]

1050FW/@ a loss of 20% driveline, should put the RW at 840.
Using a BSFC of .6, and a DC max of .85, I see needing an injector with a flow rate of 93#/hr.
The Siemens 80#, [Fl114992] inj, run at 58psi should do the job, and not have to be modified.[92.4#/hr]
If run @ 61.4psi should get 95#.
A good flow number on the intake/heads, could get the BSFC down a bit, and help w/ a flow cushion..
Right/wrong????

[joecar]

Good analysis.

Would BSFC .6 be typical for boosted application...?