Last week my girlfriend and I finished our big move from Idaho to Maine (2800 mi, 4.5 days). She drove the Uhaul, towing my Jeep. And I followed in the Evo. She is terrified of driving the car, but apparently not the uhaul. So many things to take care of with the Evo now...AFR is about .7 lean, knock in upper rpms (knock light patch), new gas (was running 91, and I found a place with 93 here), and I need a cat now (never had inspections before, and didnt have a cat on the car when I bought it).

I was living at 5500' elevation, now we are pretty close to the ocean. Im guessing less than 200' asl. The car ran like crap for most of the trip. We left ID at 5500' asl, and quickly got to around 3500-4000' asl. The WB was showing a cruise AFR of right at 15.2 in ID, then went to around 14.7 around 3500'. Then we went up to about 8000' for a breif period and and AFR went all out of whack again (~16.0). Then after getting back down to around 2000-3000' it started to settle down again. But then we where in Ethanol country. EVERY station in the midwest had ethanol in the gas and hardly any of them had at least 91 oct. The car would hardly idle, but was [I]okay[I] under cruise conditions. Then it started to get better about the time we started to run into 93 oct and more stable elevations. I was almost to the point where I wanted to unplug the battery every morning, just to reset trims.

Now that we are here, Im finding that only a few stations actually have 93 oct. With 91, it knocks pretty consistently. And only knocks sporadically in the upper RPMs on 93. I am also noticing that my WB is showing about .7 too lean under WOT. Right now Ive just turned the boost down, and changed some of my tune back to stock (excluding open loop areas). Ive yet to find a good place to get some logs. It is pretty crazy to see and feel the difference that the new conditions have on the car. It pulls like a **** compared to before.

Is the AFR being .7 lean what you would expect? I was at 11.8, tapering to 11.3 on 91 oct @ 5500'. Now it is at 12.5, tapering to 12.0 on 93 oct @ ~200', with some knock in the upper RPMs.

Im getting ready to put a HFC on for inspections. What changes should I expect to make as far as timing and fuel? Will the timing threshold be lower, since VE is going down? I am assuming that I will hit different load columns, but just want to know about what to expect.

Thanks, and sorry for the novel
-CB

edit:and I forgot to add that I was getting pretty darn close to 30mpg. I calculated it at the first couple of stops, and got over 30mpg. But then I checked my odometer using the mile markers for about 10 mi several times (pretty boring trip..) and came to the conclusion that I need to multiply all of my mileage by .95 to get anywhere close accurate mileage. I have 245/40/17s.

 

I live 75' asl. I'm running 24-25psi with 3-14 degrees timing, stock turbo, full tbe exhaust. 12.2 tapering to 11.1 at redline. Straight Shell 93oct.

360/340 DLL with just a TBE, LICP, and boost solenoid.

 

I've found that at sea level you can run less timing and boost than at 6000'. I live in the mountains 6000' and commute daily to sea level. I found that I had to tune at sea level and live with the compromise at altitude. I making 430 horse to the ground with a 3076r on cali 91, meth and a high flow cat. I don't think the cat will hurt you all that much.