Power Vision Information Thread
A quick test if you are using the Auto Tune Pro kit would be to go to Datalog>Gauges and configure 2 gauges with Front & Rear AFR, start the bike and get yourself a get yourself a piece of 2X4 (OK, dont laugh) and while watching the AFR live on the PV screen block the end of the muffler with the block of wood, then remove it and go back and forth a bit. If there is reversion getting back up to the sensor the AFR will be all over the place and will read leaner than the actual mixture. Last week I tuned a bike on the dyno with V&H Dresser Duals & mufflers with big straight thru cores and the AFR reported by the wideband on the rear cylinder was way lean due to the amount of reversion in the pipe. Also looking at your rear VE table I can see it is significantly richer than any of our true duals maps.
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Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
Extreme HDF Member
Joined: Nov 2007
Posts: 14,670
Likes: 139
From: East of the Sun, West of the Moon
Jamie.. got any experience tuning CFR mufflers in a 2-1-2 setup? These are the newer style which according to at least 1 reputable tuner CFR seems to have corrected the back pressure issue to some extent and they are tuning fairly well.
Road Master
Joined: Feb 2010
Posts: 1,237
Likes: 61
From: Albany, OR
A quick test if you are using the Auto Tune Pro kit would be to go to Datalog>Gauges and configure 2 gauges with Front & Rear AFR, start the bike and get yourself a get yourself a piece of 2X4 (OK, dont laugh) and while watching the AFR live on the PV screen block the end of the muffler with the block of wood, then remove it and go back and forth a bit. If there is reversion getting back up to the sensor the AFR will be all over the place and will read leaner than the actual mixture. Last week I tuned a bike on the dyno with V&H Dresser Duals & mufflers with big straight thru cores and the AFR reported by the wideband on the rear cylinder was way lean due to the amount of reversion in the pipe. Also looking at your rear VE table I can see it is significantly richer than any of our true duals maps.
Thanks for all the knowledge!
Road Master
Joined: Dec 2012
Posts: 848
Likes: 30
From: CO
I know this question is a little off the current topic so forgive me. But I was wondering if the ECM has any ability to adjust for altitude changes in the OPEN loop areas of the AFR table. I'm assuming not, since the only pressure sensor it has is the MAP, and if the MAP read a lower pressure(because of higher altitude) it would simply go to the corresponding cell of the table, though not necessarily lean out the mixture across the board like you would want in the thinner air. I would also assume that redoing the autotune at the new altitude would change the VE tables and solve the problem?
On another note...does anyone know how long the stock narrowband O2 sensors can be expected to be accurate before needing replacement? I remember being told a long time ago that O2 sensors are really only accurate for a few years or so.
Thanks.
On another note...does anyone know how long the stock narrowband O2 sensors can be expected to be accurate before needing replacement? I remember being told a long time ago that O2 sensors are really only accurate for a few years or so.
Thanks.
Extreme HDF Member
Joined: Nov 2007
Posts: 14,670
Likes: 139
From: East of the Sun, West of the Moon
I'm assuming not, since the only pressure sensor it has is the MAP, and if the MAP read a lower pressure(because of higher altitude) it would simply go to the corresponding cell of the table, though not necessarily lean out the mixture across the board like you would want in the thinner air.
there really is no "lifespan" for an o2 sensor per say as I understand it. When testing results dictate that it is no longer functioning according to EPA standards then according to EPA, they need to be replaced. This however doesn't mean that the sensor is not still fully functional.
I know this question is a little off the current topic so forgive me. But I was wondering if the ECM has any ability to adjust for altitude changes in the OPEN loop areas of the AFR table. I'm assuming not, since the only pressure sensor it has is the MAP, and if the MAP read a lower pressure(because of higher altitude) it would simply go to the corresponding cell of the table, though not necessarily lean out the mixture across the board like you would want in the thinner air. I would also assume that redoing the autotune at the new altitude would change the VE tables and solve the problem?
On another note...does anyone know how long the stock narrowband O2 sensors can be expected to be accurate before needing replacement? I remember being told a long time ago that O2 sensors are really only accurate for a few years or so.
Thanks.
On another note...does anyone know how long the stock narrowband O2 sensors can be expected to be accurate before needing replacement? I remember being told a long time ago that O2 sensors are really only accurate for a few years or so.
Thanks.
Last edited by fuelmoto; May 29, 2014 at 09:41 AM.
This is incorrect as the ECM bases fuel delivery exactly the same whether it is open or closed loop, does not matter if it is at 10ft or 13,000ft. The only difference in a closed loop map is there is correction based on O2 voltage.
Extreme HDF Member
Joined: Nov 2007
Posts: 14,670
Likes: 139
From: East of the Sun, West of the Moon
Yes I get that you set your AFRs, VEs, etc. for open loop when tuning, but again how can the ECM possibly know to auto-correct the open loop areas?
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Novice
Joined: Apr 2014
Posts: 16
Likes: 0
From: Europe
It does not matter whether MAP values are low because of the height, the position of the twist grip or the weather situation.
The ECM only needs to know how much air flows to calculate how much fuel is needed.
For me its only measure and a little math.
"Auto correction" is not necessarily needed.
Since I am not an expert this might be wrong but this is my understanding.
Greetings
D.Mon