Altitude Change?

[Project2G]

Hey what's going on guys? I just moved to The Denver area from Southern California. I got the gst shipped here and when I went to pick up my car I noticed my Safc2 was on a different screen so I'm not sure if the transporter messed with it or if the altitude has something to do with it. When I try to go WOT it feels extremely sluggish and won't hit full boost. Do I need to change my settings since I'm a mile higher then I was in Cali? If anyone can help me that would be great. I'm staying in Littleton, CO right now. Thanks.

 

[sbiggi]

Setting may need to be changed a little, but since dsm's use a maf, it shouldnt really need much change.
Sounds like they messed with it.

But, the car is going to be slower up here. You lost about 15% of your power.

 

[Project2G]

Thanks for the reply. I was browsing through the safc2 and realized my settings have been erased. No idea how or why but I changed a few things to make it run a little better but I am going to try to find someone local to help me create new settings because I'm now hitting fuel cut.

 

[kenamond]

I wonder if they disconnected the battery for transport. I'm no SAFC expert, but that may have wiped it clean.

If the SAFC just alters the air speed values from the MAS, then it could be that the change in density cannot be compensated for automatically and would require a bit of a re-tune.

As for losing 15%, I'm not sure if that's the case. The PR of a turbo depends on altitude. At 8000ft, atmospheric pressure is only 11.8psi as opposed to 14.7 at sea level. So the PR at 12psi (stock) boost is (14.7+12)/14.7=1.816, while at 8000ft it is (11.8+12)/11.8=2.016. So the turbo is running at a 10% higher PR at 8000ft than sea level. If you're at the top of an efficiency island in your compressor map, the altitude increase might push you to a less efficient point of the map, increasing compressor output temps, decreasing air mass to the cylinders, and increasing the propensity for knock. But at the same time, you are flowing less air and have a bit more fuel headroom, so you can increase boost a bit as long as knock or compressor efficiency aren't the bottlenecks. But the end result is a drop in power.

Okay. I'm done geeking out.

Mack

 

[n8dsmdriven]

I just received my dsm link and am going to start tuning, should i be worried about the altitude affects or density?

 

[UnsafeAtAnySpd]

Just be glad the car you drive most of the time is turbocharged. When I moved here to Cheyenne (6100 feet) from Cali last year, I felt like my CTS-V turned into an early 90s Accord. Major power loss.

 

[sag1441]

yeah N/As get raped up here. cant even get a literbike to power up in first without chopping the throttle, pullin, or preloading.