Steve in Seattle

That likely wouldn't matter, unless this car was purposely made to run open loop (very rare, and for extreme situations... and the one time I did hear of a guy trying this it was a speed-density, boosted application and was having problems... until the BLM locker for OBDII applications came out). I also heard of people tossing this idea around for 4/7 cam swap ideas (bank-specific O2 feedback can cause fueling problems), but I've never actually heard of someone using it for that (the only 4/7 swaps on LT1's I've heard of were in Carb'd or FAST PCM situations).

Even the most radical NA builds (way beyond this run of the mill 383) just adjust lookup tables and switch DTC's on/off, there's typically no "coding" or algorythm adjustments needed (the OEM PCM is VERY robust and makes table adjustments cover nearly every possibility). There are a few exceptions of course (like a BLM-locker), but most everything is "just" a matter of changing the right table value, flag.

There are very few advantages to disabling the O2 sensors... my money's on this 383 just having a normal spark/fuel change, no change on O2 operation.

As mentioned, you should have no problem with detonation. higher altitudes can use lower octane, and even if he DID drive it to sea level on 1 tank he HAS knock sensors... they can adjust spark to compensate until the next fill up. (but honestly my build probably has more compression than this 383 and we run 91 octane at sea level ALL the time. Nothing spectatular if you have functional O2's and knock sensor (and a big enough cam )

sbs

Tons of people run open loop tunes. And most of them are not for "extreme situations", they are simply due to tuner ignorance or incompetence.

I prefer to not ***ume how the car in question was tuned, especially since that could lead to the OP getting screwed.

Steve in Seattle

Ok, iff you say so. Most incompetant tuners (I'm not gonna name someone specificly mind you) wouldn't know HOW to set up a open loop tune properly, but that JMHO.

ummm... ok, apparently you didn't read the thread or know what open-loop tuning requires. You honestly just can't do an open-loop tune at 14.7:1 A/F like you can in closed loop with O2 feedback. An open loop tune almost universally requires the tuner shoot for a richer A/F to avoid lean-out in the various conditions it can see. If the car happens to be a open-loop tune it's already rich.

This is all beyond the point however... if it's fine in texas with 93, it'll be fine in colorado with 91. Like I said, we run more compression at sea level in this area without issues.

WS Sick

That cam isnt too compression friendly woulkdnt you say.