Appreciate it, will definitely have a non stock air intake, will be a 96 LT1 T56 put into a 61 Rambler wagon going on an 87 monte carlo SS chassis. One of my usual mutt builds!
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Hiya,
Since you are building a new intake tract, use the 01-06 Truck MAF, it is much more forgiving to intake tube changes(Initial tune I posted is set up for that). Make sure it has at least 12" of straight tube after the MAF, and a high quality air filter before the MAF that will reduce any turbulence before the MAF. These things will drastically help you in the tuning process.
The Express uses the same MAF as the F/Y car LT1 or early LS1. Should be able to copy the LT1 injector data into the 0411 tune. The Van tune will need some timing added to it. From there tune the VE tables with the MAF failed. Once you get the VE tables dialed in, re-enable the MAF and start tuning the MAF curve. The LT1 should pop right off on the van tune and run fairly well. But it will definitely be down on power without some timing added to it, van tune only has like 24° total advance.
Personally I would use a DBC P59 and use the Mexican GMT800 L31/5spd tune as a starting point. Segment swap over the 6spd trans segment from a 2005 CTSV that also had a P59 with the same OS.
Same MAF sensor, same ICM on the vans as the LT1. LT1 is also sequential. Not hard toduplicate the LT1 timing curve if you know what the gm/cyl value is throughout the RPM range at WOT as well as what the MAP sensor reads at WOT. Then you can rinse and repeat for any rpm and load. Spark map in my aluminum head 383 L31 would probably be very close for an aluminum head LT1. I can post that tune.
Agreed. I would definitely expect to use injector tables that math the type of injector that is installed. The L31 Poppet style injectors are very different from traditional fuel injectors.Quote:
I wonder about '0411 injector parameters LT1 vs. L31?
IME the stock one ton van injector voltage compensation is incorrect below 10V. If left stock our commercial vans have difficulty starting with a low battery and the exhaust is very rich at idle if the voltage drops. Leaving those tables intact could really mess with traditional injectors.
The injector parameters are from TunerCats OBD2 software:
1997 LT1
Attachment 19521
2002 '0411 L31
Attachment 19522
2002 LS1 .bin file:
2002 LS1
Attachment 19524
Been a little bit, I wasn't getting notifications that this thread was being replied to but wanted to say thank you all for the help. Since I started this post I actually found an 02 Express van in the junkyard and grabbed the PCM. Turned out to be a 156 OS which is a common one and I could read it with tunerpro. This one was a factory 350/4L80e tune, and I did a segment swap to make an M6 tune using an 02 z28 file for the transmission side. I still have to update the injector data, thank you for that help! I will be running the stock 96 LT1 injectors since the engine is stock. With the mention that the LT1 uses the MAP sensor for spark tables, should I fail the MAF and just run in SD mode, or better to keep the MAF? I do not have a 96 timing table to look at, but I do have a 95 LT1 tune to reference that I can copy over to the van tune. Because I will be using the 4x crank wheel it will be running in batch fire mode, no more sequential.