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Old 01-16-2013, 10:35 PM   #26
Stelvio Dreamer!
Mike.C's Avatar
Joined: Dec 2007
Location: Brisbane-Australia
Oddometer: 592
Originally Posted by grneggz;20503073[B
It then sends this information to the Power Commander V and automatically corrects it while you ride.[/B]

I have have had a PCV with Autotune on my Guzzi for years.

Actually everyone is right, just not putting the whole picture on the wall

The key here is "corrects it". Corrects it to what???

Well simple.. An AFR (Air Fuel Mixture) map programed into the PCV. This AFR Map is generated by either one of two procedures and does not change "on the fly".

1) Put the bike on a dyno, and use an O2 sensor up the tail pipe to measure the AFR of the engine, from which an new target AFR map is generated and uploaded to the PCV
2) Use the wide band O2 sensor attached to the auto tune and ride , accept trims, ride accept trims, ride accept trims etc etc etc until with each ride the iteration in the adjustement of the base map to achieve the target AFR is very small.

What the auto tune then does is NOT vary that base map, it just accounts for varying riding conditions by trying to get the AFR in the engine as close as possible to that map as external conditions change such as air density, air temperature, and some other factors internal in the engione that affect fuel burn etc. It does this by constantly monitoring the AFR in the engine as sensed by the wide band O2 sensor in the exhaust, which is the real magic of the auto tune.

A Dyno generated map can't of course do any of this real world adjustment of the fuelling into the engine as conditions change, it just blindly shoves fuel into the engine according to the programmed map without any consideration for external factors that may be different from the conditions in the workshop when the bike was on the dyno.

THe PCV with AT is without doubt a fantastic bit of kit on the right bike and for some riding styles or requirements..
Cheers, Mike
Don't just look at it - Ride the bloody thing!

Mike.C screwed with this post 01-16-2013 at 11:50 PM
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