Subaru Enthusiasts Car Club of the Sierras - View Single Post

knucklesplitter · 2009-09-09, 04:42 PM

OP: If (and only if) you have stock injectors and a stock or stock-sized intake then you will be probably be safe to drive the car IF (and only if) you stay out of boost. Even a few psi boost at part throttle would be okay too, but better safe than sorry. This can be harder to do than it sounds. You will also likely get CELs.

Ed should be able to get you a driveable base map to install for now. If not then I could put one together for you.

The most common issue with tunes related to elevation changes is boost control. Tunes at sea level are usually safer when going high than tunes at elevation going low for the following reasons:
-The car makes less power at high elevation at the same boost, so there is less load on the engine at higher elevation (all things being equal).
-The ECU program has tables that cut boost when the car goes up in elevation. Generally you will have lower boost up here than down at sea level unless the tuner tweaks these tables. BTW the Cobb Race Tuner software does not access these tables as far as I know, and that pisses me off.
- Turbos spool slower at higher elevation

The MAF sensor and barometric pressure sensor compensate the fueling at elevation... usually.

2009-09-09, 04:42 PM	#12
knucklesplitter EJ205 Real Name: Matt Taylor Join Date: Jun 2005 Location: Cousin-Fck, Carolina Posts: 1,475 Wish in one hand and sht in the other...	OP: If (and only if) you have stock injectors and a stock or stock-sized intake then you will be probably be safe to drive the car IF (and only if) you stay out of boost. Even a few psi boost at part throttle would be okay too, but better safe than sorry. This can be harder to do than it sounds. You will also likely get CELs. Ed should be able to get you a driveable base map to install for now. If not then I could put one together for you. The most common issue with tunes related to elevation changes is boost control. Tunes at sea level are usually safer when going high than tunes at elevation going low for the following reasons: -The car makes less power at high elevation at the same boost, so there is less load on the engine at higher elevation (all things being equal). -The ECU program has tables that cut boost when the car goes up in elevation. Generally you will have lower boost up here than down at sea level unless the tuner tweaks these tables. BTW the Cobb Race Tuner software does not access these tables as far as I know, and that pisses me off. - Turbos spool slower at higher elevation The MAF sensor and barometric pressure sensor compensate the fueling at elevation... usually. Last edited by knucklesplitter; 2009-09-09 at 05:31 PM.