EFI and elevation changes
Banned
Joined: Jan 2007
Posts: 2,301
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From:
RE: EFI and elevation changes
The MAP sensor is what determines outside barometric pressure (elevation and cold heavy
dense cool air vs hot dry summer air). (this is a simpified explanation)
It compares outside air with what is happening in the manifold.
Thus determining (with other sensors) idle, cruise no load,
cruise pulling up a hill, WOT.
It makes the initial computation decision of amount of fuel needed.
The O2 sensors is an after the fact decision. If the fuel was originally too
rich or too leanthey further refines the process.
How the PCiii will act don't know.
But either way you'll be ok. Perofrmance and mileage may suffer somewhat,
but should be enough that you would notice it.
dense cool air vs hot dry summer air). (this is a simpified explanation)
It compares outside air with what is happening in the manifold.
Thus determining (with other sensors) idle, cruise no load,
cruise pulling up a hill, WOT.
It makes the initial computation decision of amount of fuel needed.
The O2 sensors is an after the fact decision. If the fuel was originally too
rich or too leanthey further refines the process.
How the PCiii will act don't know.
But either way you'll be ok. Perofrmance and mileage may suffer somewhat,
but should be enough that you would notice it.
Cruiser
Joined: Mar 2008
Posts: 105
Likes: 0
From:
RE: EFI and elevation changes
I have on 07 ultra with stage 1 down load. Runs on the lean side but when I ride at 2000 ft.or higher I get 4 MPH better
millage even going up and downin the moutains. Never pings and runs great!
Ride On !!!
Outstanding HDF Member
Joined: Apr 2007
Posts: 2,046
Likes: 1
From: Canada
RE: EFI and elevation changes
Ilive at the foot of the Rockies in Alberta which is 3500' above sea level and run the rockies almost every other weekend up to 9000' and not a single issue. I am running a Tmax on an 07 bike though. 
Cruiser
Joined: Feb 2008
Posts: 166
Likes: 0
From: California Desert
RE: EFI and elevation changes
02 Ultra with ECM flash and SE 95" stage II. Have been to the top of Pikes Peak (14,110') and several times up to 10,000 feet with no problems at all. Fuel injection compenates just fine. Don't know about PC III.
Stellar HDF Member
Joined: Apr 2007
Posts: 2,339
Likes: 486
From: Nor Cal
RE: EFI and elevation changes
thats what FI is all about it changes for you based on altitude and temp, dosent matter where you tuned it at. if it was a carb your buddy would be right.
Mike
Mike
Stage I
Joined: Mar 2020
Posts: 1
Likes: 0
From: Broken Arrow OKLAHOMA
Elevation issues
This is probably a stupid question, but I am planning a trip to the Rockies and one of my buddies keeps telling me that I will have issues with my engine pingingsince my tune was done at (roughly) sea level. I have a PC III, and always thought the PC III adjusted the amount of fuel depending on the air density sothe air fuel mixture was constant regardless of elevation.Am I wrong? Help me out guys!
Club Member
Joined: Apr 2016
Posts: 11,448
Likes: 8,275
From: Inland NW
We all struggle with the lack of o2 on a NA engine.
Damn, this is an old thread!
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