How should I wire my LS?

Woot! Love seeing this one come together. 

In reply to DILYSI Dave :

You are a lot braver than I am.  I labeled pieces of blue tape for every connector on my engine harness.

So a possible plan diversion bump. 
 

It appears that the combination of manual transmission and E38 truck ECM has issues.  Since there was never a manual truck, it wants to see a 6L80 talking back. 
 

There are some possible work-arounds by flashing it to think it's a Corvette, but then you also need a Corvette pedal and throttle body.  And there seems to be a not insignificant number of folks who manage to brick the ECM when trying to convert it to a manual version.  And then you lose VVT because there was never a manual and VVT in the same vehicle. 
 

Given these, I'm leaning more towards aftermarket.  I'm up for hearing why OE is still the way though. 

In reply to DILYSI Dave :

No VVT in a manual trans?

I know DoD/AFM was never used with a manual, did not know that about VVT.

Can you move to an E67? Not sure that if requires a reluctor wheel change.

If it's a matter of CAN signals, you could probably build a 6l80 spoof box pretty easily and cheaply. That might be a fun project.

Pete. (l33t FS) said:

In reply to DILYSI Dave :

No VVT in a manual trans?

I know DoD/AFM was never used with a manual, did not know that about VVT.

It appears so, though I'm open to being wrong.  Read a thread on HP tuners where they speculated that GM feared fast revving and open clutch tagging valves, so they only put VVT in automatics.  Dunno if that's valid or not, but mine will be MUCH faster revving than anything GM would sell, given the 7.25" clutch and flywheel setup it's gonna run.  

Keith Tanner said:

Can you move to an E67? Not sure that if requires a reluctor wheel change.

If it's a matter of CAN signals, you could probably build a 6l80 spoof box pretty easily and cheaply. That might be a fun project.

Maybe?  But the fun project is supposed to be the car.  The engine management is just a step along the way, not another project unto itself.  :)

In reply to DILYSI Dave :

I'm looking into it :) I have a lot of GM documentation on CAN messages, maybe I can make a little doodad for you. I'm the one who thinks this would be fun.

If you can, that doodad would likely be kinda popular.  And if you're making a doodad, the ECM also wants to see a VSS that often is missing.  They will run without it, but I hear it's compromised.

Keith Tanner said:

Can you move to an E67? Not sure that if requires a reluctor wheel change.

If it's a matter of CAN signals, you could probably build a 6l80 spoof box pretty easily and cheaply. That might be a fun project.

6L80 had an ECM/TCM setup.  So you would need to spoof data outputs that make sense, not just signals.

That's one reason I went to a Holley.  I remember spending hours scouring HP Tuners forums to try and figure out if I could use an e38 (6l80-based) with a manual.  The results were not encouraging.

This looks pretty encouraging. 
https://forum.hptuners.com/showthread.php?36796-wont-rev-past-4000-RPM/

So we need VSS and a signal for "not in park" which is basically the neutral switch on a manual. Duplicating those with a little $25 box would be easy. What else?

I love that it is "So we need..." vs "So you need..."

GRM family is best family.

Bump....

My build is progressing and I now have a Haltech R3 in hand and am about to dive into wiring. I'm planning on 90% of the sensors staying the OEM GM stuff, but there are a few deviations I'm considering. Figured I'd throw the door open for input and advice here as well....

1. I want to replace my original oil pressure sender with a pressure / temp sender. Probably the Bosch one.

2. I likely will want to integrate a crankcase vacuum sensor to monitor the dry sump and vacuum regulator. Any input on a good one?

3. One of the Haltech groups suggested using the same Bosch temp / pressure sensor to feed fuel data as that data would let the ECU compensate better for fuel density. True story? Worthwhile?

4. MAP vs MAF? The donor vehicle had an IAT and MAF integrated into the intake piping and a MAP in the manifold. My gut feeling was to go with a TMAP in the manifold and eliminate the MAF. But if there's a good reason to retain the MAF I don't want to let wiring simplicity and/or laziness override that. Thoughts?

5. E85 Sensor - No immediate plans to run E85, but I've run it in the past and could see using it in the future. That being the case, I'm tempted to go ahead and wire it in now even if I'm not using it or am just running E10 through it.

6. What am I missing?

4. From what I've seen, running a MAF is the real secret to making an LS run well. I forget all the details, but once we zeroed in on getting that calibrated properly the driveability of the engines improved a lot. 

In reply to Keith Tanner :

I cannot see any reason to not run a MAF.

Calibrating them is stone simple and once you do that, 80% of your tuning is done.  Fix the VE tables, also stone simple, and that is another 15%.

Run a MAF. I have not heard of anyone having as good of drivability off throttle or part throttle as MAF tuned motors (vs SD tuned). 

Suggestion #1, make sure ALL grounds are readily available for inspection, clean, make amazing contact, have appropriate contact/connectivity and you will eliminate 75% of troubleshooting issues once running. 

Slight threadjack for what may be a really dumb question - I may go with a turbo in the future on my LS swap.  Right now, still running the MAF, but have noticed it seems like turbo builds I see on youtube end up deleting it.  Is that just to make piping simpler, or is there a valid reason to ditch it for a boosted setup?

eastsideTim said:

Slight threadjack for what may be a really dumb question - I may go with a turbo in the future on my LS swap.  Right now, still running the MAF, but have noticed it seems like turbo builds I see on youtube end up deleting it.  Is that just to make piping simpler, or is there a valid reason to ditch it for a boosted setup?

I'm not tuner, but if I were to guess its for piping simplicity, eliminate potential maf sizing restrictions, and possibly because its easier to tune a car when you only look at WOT AFR's then it is to deal with part throttle applications where the MAF based tunes really shine. 

In reply to Olemiss540 :

That is the thing.  Power enrichment is a separate map from the VE and the MAF tables.  It knows the injector characterization, it knows how much air is going in, it looks at the PE table to get the right AFR.

You don't tune like a carb, you characterize the engine and the airflow and THEN define the air fuel ratio.  Much simpler.

It is just waaaaaay easier and better to get the MAF curve right because then fueling and ignition timing are correct.