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Old 05-15-2013, 08:47 PM   #218
ebrabaek OP
Beastly Adventurer
Joined: Jan 2010
Location: Grand Valley, Colorado
Oddometer: 4,871
Originally Posted by roger 04 rt View Post
Your tables are very interesting. There is no doubt that autotune is functioning and learning from the Wideband O2 sensor. In a way it's too bad you don't have a second bung near the first one so that you could monitor AFR and see if you're really getting your target AFR.
When we had it on the dyno ( I think about 30 runs through out the day) the 4 foot sniffer were awefully close to the values indicated by the AT. I know that is not as accurate, as it sat about 18 inches further back than the AT O2 bung.

-I'm assuming you run ethanol.
Actually down here on the NM border with old Mexico, we have very little ethanol. If I hop one state north to CO, I use Techron, as they run alot more ethanol than we do.

-I'm going to have to think about where you have limits in your settings and will be back to you with some questions.
Sounds great. Always here to learn more, and improve.

-It looks like at 6500 rpm and above for tps 10% and above the trim is maxing out at 10%.
-The 25% numbers may be max-out numbers too. And that's awfully large.
I am not sure what is going on there, but again these trims have NOT been accepted,and added to the base map. As we added my own CF pipe....then the headers, we saw a very big shift towards lean. The then BMS-K ( no PC-5/AT) were faltering far lean, as we were seeing the towards 18 AFR. I simply think that the 25% is needed in that power regime, to keep the target AFR. Mind you the base map is just about a Zero map, corrected for off idle throttle hop. imho....there is no way we would see such large numbers with stock header, incl, CAT, and pipe.

-With an AFR target of 13.2, really lambda 0.90, and running E10, you would expect about a 14% correction. Which is what we LC-1ers see.
Could be, as I have not tested for ethanol. The pumps states that it might include up to 10%, but I personally think it is lower.

-I'm surprised that some of the high rpm/TPS numbers aren't single digit or negative.
I would like to contribute this to the better flowing exhaust system. The stock BMS-K is barely keeping up.

-Are the auto tune trims additive to the fuel map trims? If they are at 2%, 1250 rpm you're adding 45% to fuel—20% map plus 25% trim to hit 13.5. I question that. That doesn't seem right.
Correct, they are not added, as the AT is inactive below 2%, the pc-5 runs with the 20%, that I added for the throttle hop. I think I can decrease that to 10%, but have not done that yet. As you hit the 2% the trim values is all, and the base map of 20 is negated. I do believe it takes a few seconds though, as I do follow the activation of AT at 2%, could be transitioned better. I think I will decrease the 20% to 10, and see if the hop changes, as that is the only reason for the 20%.

Does the PC V AT have a heater calibration or free air calibration mode?
I am not sure.

What altitude do you ride at? Widebands are altitude sensitive.
I was told that it adjust the altitude only through the O2, and what it measures, as it globally ( final fueling) is running closed loop thus will not need the pressure sensor, as compaired to open looppers... I guess below 2% thottle is open. It was dynoed at 5500 feet... I ride here in the southwest at 4500 feet, but have spend several days up to 11000 feet, and it simply is fantastic, practically so to speak.

How would you feel about saving your current tables and then doing the following. Leave AFR targets as is, zero out the fuel table and trim table. Ride for a week and repost the trim table. Maybe even post it after each ride. It would be interesting to see it develop.
Let me think of that. I will see if I can save the trim table..... I don't think I can, but I don't see why not, I can replicate most of it, with the exception of 700 miles of dirt.

This is all pretty interesting.
Thanks for your input Roger. I have been a little apprehensive to change anything, as it seems to work so very good from the get go, but I will think it over to erase the fuel trim table, as The current table have much technical dirt sections in there, but in reality, I cannot see why that would make a difference.


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