LM4 vs LM7 VE tables
Thread Starter
Teching In
Joined: Mar 2024
Posts: 4
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LM4 vs LM7 VE tables I am in the process of swapping a 2004 LM4 (5.3) in place of my old 2001 LR4 (4.8) into a P38 Range Rover LS swap. Iron block was waay to heavy for the car. Since I had to do a TON of custom harness grafting, I am trying to avoid replacing a harness. My logic had been to just put a 2002 LM7 tune in my 411 and call it good. To be sure, I pulled the bin file data out of the LM4 PCM (newer Blue/Green style) and discovered that there is a huge difference between the VE tables for the LM4 and LM7. Everything I have read indicates they are essential the same motor. Other than the aluminum block of course. Anyone have any ideas why? Or do I just load the LM7 stock tune and call it a day. OBTW, the LM7 is running pretty darn good on the 4.8 tune, but is throwing P1884 codes at me. I assume the 4.8 VE tables are pushing the limits of the fuel trim corrections trying to feed the 5.3.
TECH Senior Member
Joined: Jun 2016
Posts: 22,303
Likes: 3,619
From: Central Cal.
The difference in displacement (4.8L vs 5.3L) makes a big difference in tuning.
You're right, they are essentially the same engine, besides block material and displacement.
Same cam, heads, intake manifold, sensors, and injectors.
It should plug and play between the two.
There should be a tune for the LM4 in a depository somewhere.
You're right, they are essentially the same engine, besides block material and displacement.
Same cam, heads, intake manifold, sensors, and injectors.
It should plug and play between the two.
There should be a tune for the LM4 in a depository somewhere.
TECH Fanatic
Joined: Jul 2022
Posts: 1,043
Likes: 393
From: Alaska
I pulled a trashed 5.3 out, and stuck in a 4.8, started right up and ran alright with stock tables.
Got better with base running airflow adjustment. NOTE : the VE table self adjusted when the correct DISPLACEMENT was keyed in.
Also, for some reason, the 4.8 can take substantially MORE spark advance.
.
The MAIN difference between the 4.8 and the 5.3 is that the short stroke engine makes the same power as the heads/ cam airflow will permit, it just does so at a few hundred RPM higher.
Short stroke motors REALLY run well in front of LOW gears.
Got better with base running airflow adjustment. NOTE : the VE table self adjusted when the correct DISPLACEMENT was keyed in.
Also, for some reason, the 4.8 can take substantially MORE spark advance.
.
The MAIN difference between the 4.8 and the 5.3 is that the short stroke engine makes the same power as the heads/ cam airflow will permit, it just does so at a few hundred RPM higher.
Short stroke motors REALLY run well in front of LOW gears.
Thread Starter
Teching In
Joined: Mar 2024
Posts: 4
Likes: 1
LM7 tune worked Thanks for the help on this. Got the LM tune loaded in tonight and all seems well so far. No more CEL and a nice power bump. This should do nicely. A huge improvement over the old setup
