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High Altitude Efi Maps?


tsiklonaut
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Never heard of one, but don't think it is necessary as the efi system should adjust automatically for air pressure and outside temps

 

You're sure it measures the pressure too? To my knowledge it's just the temperatures (air and engine), but since 2-strokes have no Lambda-sensor feedback from the exhaust for mixture adjustment thus they cannot adjust for the high altitude (this must be done via proper re-mapping?)

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You're sure it measures the pressure too? To my knowledge it's just the temperatures (air and engine), but since 2-strokes have no Lambda-sensor feedback from the exhaust for mixture adjustment thus they cannot adjust for the high altitude (this must be done via proper re-mapping?)

Yes,there is a sensor for the pressure.

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Yes,there is a sensor for the pressure.

 

Yep, spot on! While it's not marked in any specs I found some nice OSSA EFI info here. Basically OSSA has built their own version of closed-loop EFI via pressure sensor (most EFIs use Lambda (O2-) sensor for mixture instead), hence it should adapt the correct mixture according to altitude. Case closed. :)

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A pressure sensor doesn't make it closed loop or even close to behaving like a closed loop system, It will only measure negative pressure similar to a Maf sensor.

 

Without a lambda sensor to measure the state of compustion, the ecu is only guessing the fueling.

 

Having said that a properly mapped Ossa is fantastic, I really like these bikes, I've ridden a really good one mapped by Cambs Trials.

 

Enjoy it while parts are available!!!

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  • 7 months later...

Not exactly on topic- but does anyone have an explanation on what the different maps that are available do?

 

Some seem self-explanatory, but others that have things the ++ at the end. Perhaps the 'road' 2nd map is extra rich?

 

maps%20ossa_zpswupg1pst.jpg

Edited by lotus54
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Anyone tested their EFI OSSAs on high (2500+ meters) altitudes?

We have two events here in the Sierra's at 7,500 and 7,800 ft (about 2,500 meters+) and a  couple more at 5,500 ft (1,800 m); ridden the OSSA 280 at most of them and the power is down slightly, idle is lower but the rest of the behavior is fine.  So much so I never thought too much about the elevation.  The vertigo has a special map (#4) for high altitude but I forgot to run it this last weekend (7800 ft).  Ran pretty good on map 1 but I wish I would've remembered #4, heard it ran great on that.

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I was on a bus recently at about 11,000 ft. the bus had no problem, the cars and motorcycles had no problem, only the cyclists looked a bit knackered. If the Ossa can't cut it with these mundane everyday vehicles it just about says it all about 2T EFI.

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