Are speed density tunes dramatically effected by elevation change? I believe Evo X ecu’s can adjust for elevation changes, but I’m not sure if the evo 9 does on speed density.

thanks in advance… I’m sure I could google some info, but it’s been a while since I posted on the forums.

 

Yes. Once you remove the MAF, which contains the static pressure sensor, your ECU has no way to adjust fuel for altitude. This means if you were tuned at sea level and travel to 5000 ft, where there is 15% less oxygen, your SD tune will be way too rich.

 

You can get the SD harness to add a pressure sensor for baro compensation

 

This would explain my issue at Portland International Raceway. (500ft above sea level)

I tuned the car two nights prior, fp green 25psi tapering to 24psi in Las Vegas. (2200 ft)

On my second flying lap the car started breaking up on the front straight, so I got out of boost. It started breaking up on the back straight again so I called it a night for the road course. Once I got back to the hotel, I lowered the boost just slightly. I also added a full point richer of fuel in those load cells. The rest of the weekend was auto x and speed stop, but I had no more issues with it breaking up. Although, I never hit 4th or 5th gear like I was on the road course.

 

I want to get the mrfred spoolinup harness but have not been able to find the 2D SD active baro patch anywhere. Do you remember seeing it anywhere by chance?

 

@unkn0wn. my friend @Pal215 is searching for the exact same patch to remedy this situation. He bought the MrFred harness but also needs the patch. He's a really good mech and tuner so I have confidence that he'll eventually get it to work. You might want to stay in touch or partner with him on this.

 

Where can this harness be purchased? I'm also on SD.

Thanks

 

Bump this:
Good information if I ever take my car out to the mountains of California

 

Bump for good info!