BBC swap - which OS to run?

I need advise on which OS to run for my BBC swap. I've been tuning and tuning an 02 Camaro OS but can't seem to get it tuned the way I think it should run.
My biggest issues are:
- Bank 2(even) runs very rich compared to Bank 1 (odd) at idle and part throttle.
- #2 plug gets fouled bad, tends to be pig rich at idle.
- It has a major lean spike on tip in when going WOT
- Unable to log 4L80e specific channels

Car is a:
- 96 Impala SS
- controlled by a 0411 PCM
- running 12212156 OS (02 Camaro LS1) with 4L80E segment swap

Engine:
- L21 454 from a 2000 school bus
- .060 overbore (468 cid)
- Forged flat tops at 8.7:1 SCR
- Stock 4" crank, forged rods
- AFR 265 Oval heads
- Straub Tech cam 229/229 at .600/.600 on a 110 LSA
- Holley EFI intake w/4150 flange with Holley elbow
- Holley 95mm TB
- Accel 44lb/hr injectors
- CNP ignition (LS1 coils)
- Custom LT headers 2 1/8" primaries, 3.5" collectors

Transmission:
- Built 4L80E - early model rebuilt in 2000.
- Circle D 3900 TC

L31 express van file with a 4l80 segment from factory. 01 express van tune file in the repository.

The one in the repository is for a 1500 V6/4L60E
12208322

BTW, will that work with a 24x reluctor and Coil Near Plug ignition?

Now I'm curious to know what options exist in specific LS Calibrations. Is there a cross reference chart that lists all of the options, like DBC vs DBW B's, E-fans, 4L80E, etc?
Is it common practice to use whichever fits the best, and then do a segment swap to get things like E-Fans and such into the other calibration?

2002 Express in the repository, not 2001.

No opinion as to whether that's the right one to use for this situation, but the switch from 4x crank to 24x is at System > General and the Crank Lo Res option - '1' for 4x, '0' for 24x.

Thanks for saving my fumble there. blindsquirrel

Quote:

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Originally Posted by blindsquirrel

2002 Express in the repository, not 2001.

No opinion as to whether that's the right one to use for this situation, but the switch from 4x crank to 24x is at System > General and the Crank Lo Res option - '1' for 4x, '0' for 24x.

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Thanks for chiming in.

The reason I question using the LS1 calibration is because of the Tip In lean spike and the unbalance (split bank) fuel trims. I'm obviously not tuning an LS1 engine, or even a L18 for that matter.

1. Does plenum and intake runner volume make a difference when selecting a calibration file?
2. Is there a table for setting plenum volume in an Gen3 calibration file?
3. How do you fix the lean spike on tip-in?

I'm trying to solve the split bank fuel trims by tuning the VE and MAF tables by splitting the difference between two lambda sensors, one in each bank. I'll then let the CL fuel trims sort out the difference per bank. Mind you there isn't much difference between the two banks in PE mode, just at idle and part throttle.

Transient fueling is likely the tip in issue. Fixing your transient issues will slightly alter your fueling so your VE table must be dialed back in afterwards. I might get some flak on this but i would be running this in open loop without stft at all.

Quote:

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Originally Posted by Oleblu

Transient fueling is likely the tip in issue. Fixing your transient issues will slightly alter your fueling so your VE table must be dialed back in afterwards. I might get some flak on this but i would be running this in open loop without stft at all.

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Which are the transient fueling tables?
What approach do you take to adjust them?

I suspect that a GEN 3 ECU, or least an LS1 calibration, can't handle the volume of air at tip-in for my engine.

• The stock L21 intake appears to be a lot bigger than an LS1 intake.
• My current induction setup (Holley BBC single plane large oval, Holley 4150 elbow, Holley 95mm taper TB) is even bigger than that of the L21.

A GEN 4 calibration has a setting for "Manifold Volume". I've read that it's vital for tuning out lean spikes at tip-in.

• Is it possible that my intake volume is more than twice the size of a stock LS1 intake?
• Is there a setting in an LS1 calibration for adjusting manifold volume?

There is no manifold volume adjustment in the p01-p59 pcm. In the fuel tab under transients you will find multiple tables multipliers and adders

Quote:

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Originally Posted by blindsquirrel

2002 Express in the repository, not 2001.

No opinion as to whether that's the right one to use for this situation, but the switch from 4x crank to 24x is at System > General and the Crank Lo Res option - '1' for 4x, '0' for 24x.

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Just need to clarify a key point. What firing order do you have to use with the 02 Express calibration and 24x with CNP ignition: LS, or SBC?

Hi there, I've got a similar 454 project in the works so here's something on the firing order, the 7.4 is Vortec based either in L29 versions common to Suburbans, Express vans, GMT400 trucks from 1996 to 2000. The L21 version used in Kodiaks, Topkicks, some Isuzu chassis & motorhome chassis 1998 to 2001. Firing order 1,8,4,3,6,5,7,2. Distributor rotation clockwise.

I am working on getting my 1997 0411swap CNP up and running as well, and I am having the SAME exact issues as you originally ran into. I know this was a few years ago but could you ever figure out why you have one bank running richer than the other? I am also running a basic ls truck tune setup for the correct firing order and LEXTECH helped me get it setup to fire up after following his wiring instructions.