I'm at 5000 ft and I will be going to sea level to race. What exactly should I be looking at. I know fuel and boost for sure, but is there anything else that could be that out of wack?

Cory

 

anyone?!

 

If your tune has been made @ 5000ft, you will knock @ sea level...
I just experience the same situation going from Mexico city (7200ft) to Acapulco (sea level)....
Get prepared to adjust AFR and timing!!!
I guess something can be done with the barometric compensation because it's clearly bad calibrated from factory but I did not do any research yet.
Good luck.

 

i also live in méxico, if i go to sea level i have to lower wdc about 15% to get the same boost, also change fuel and timing for knock

 

Did you have knock problems simply because you went into higher load sites that weren't previously tuned correctly?

 

Actually, loads does not appear higher. My tune was "perfect" for Mexico's altitude (0 knock ; continous 11.2 AFR tap @ 10.8) and the CEL starts to turn up while I was getting closer (and lower) to sea level (I think it starts to flash arround 5000ft so may be you will have less to compensate)...
I did some logs and catch some knock...
It is not linear, I just got alerts right after spool up (2-3 knock sum) and high revs (6-8 knock sum)...
I had to adjust some AFR and take out 2-3 degrees timing in high rev to still running 10.8 - 10.6 AFR without knock... (boost set 22psi tappering 19psi).
With a bit of luck, barometric compensation starts to do it really bad after 5000 feet!!!
Please keep us informed!
Cheers.

 

log it and adjust the tune as necessary

 

I moved from Idaho (5500asl) to Maine (~0), and drove it in the evo. In the first day of the trip, I wound up having to turn the boost down. Knock light was going off. Got here and retuned, and wound up taking around 2* at peak tq and 2-3* at redline. And had to richen up afr to get back to where I was.

Like Mellon said...You just going to have to log and adjust accordingly.

Also, when I was there at 5500, I would race at 3000 or so. All my tuning was done at 5500, and I never felt like it was "right" at the track. Maybe it was just me making excuses for my driving. But Im pretty sure the difference in altitude had something to do with it. If you dont log and retune, expect to be a bit slower than you should be.

 

The ecu will try to make adjustments however on a stock power scale. Just have to log at sea level and make adjustments.

Plug heat range may need to be cooler if your borderline now. And absence of knock does not mean heat range is good, it's for preignition

 

Is it safe to assume that if a stock ECU is tuned at sea level the AFR is enriched as altitude increases? Has anyone in a valley observed this on their wideband gauge as they drive up into the mountains?

 

I noticed that My afrs at 5000ft are 11.1-11.2 and when i went to sea level they dropped to 10.5-10.6... I had to turn the timing down 3-4* at peak torque and towards redline... my boost went up to almost 24(22 at 5000ft) but I did make more power! 285 at 5000 310 at sea level. All in all, took me about an hour to fix.
Edit: I will try and post logs for difference... also wanted to say my power curve shifted to the left about 500 rpms so I did a little tuning around that as well!

 

Any thoughts??