LS1LT1 Forum banner

Impala tune

1300 Views 2 Replies 2 Participants Last post by  Poda
I have a 1994 Fleetwood.. LT1, 4l60e.. aka, an Impala SS in tux.
Car has no mods, and on this motor I'm looking for the most optimized bone stock LT1 possible
If I remember correctly (and I don't always do, so feel free to correct me) the Imps were tuned slightly differently than it's Caprice/Roady/Fleet LT1 counterparts
In my ongoing research to tune the car, I saw somewhere that someone was thinking of putting a 94 Impala Tune, with the Caddy V4P (Towing Package good for 7000lbs) pressure table section, into a 94 Roadmaster. I understand that the V4P is a great tune to have tranny wise for longevity and optimal shifting if you're going to be enthusiastic with your right foot in a 4500lb car..
So the burning question is: what's the difference between an Impala SS tune and a basic Fleetwood/Caprice/Roady tune? Specifically in the engine management.. obviously tranny tables can vary, as well as rear end, etc. But that's easily changed over
I can attach the .bins for each if need be..
1 - 3 of 3 Posts
TunerCat and TunerPro have .bin compare functions. I took a quick glance comparing the Impala SS to a stock caddy and a Caddy VP4. Just engine management settings (not transmission). The spark, VE tables were basically the same. O2 rich/lean was set a little leaner for the SS and caddy has speed limiter MPH & RPM lower than the SS. The SS tune I looked at had PE fueling differences over the caddy tunes. Looks like all the drive-ability (and V4P towing) differences were in the transmission, TCC lockup tuning, plus each has hardware, suspension and mechanical differences. I think the VP4 has some different transmission internals, but don't really have time to research that out. Bottom line looks like putting a caddy tune in a SS will richen it about 1-2% and it will drive like a family sedan. Early softer shifts, more TC engagement,w/RPM limiter around 48-4900 and and speed limiter set at 108. Caddy tune may have a less fuel in PE mode, not sure if that's seat of pants noticeable. As far as the engine it will run without any noticeable differences.
See less See more
Thanks Bobdec.. So if I put an Impala tune on my Caddy, I'll lean it out 1-2%, harder shifts, higher speed limiter, less TC engagement.. That could actually be an improvement ;)
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.