PC III map after Barbarian mod

Chuck35 · Aug 8, 2012

So I bought a PC III from a member here, removed cats from headers and did the Trooper mod to a pair of Gen 1 cans.

I returned the 02 settings to the stock 10's across the board and left the (Barbarian mod) wire in place. I removed the 02 sensor.

Prior owner had cut out the back side of the airbox. (nice job)

Every map I tried had huge swings from rich to lean and I could feel them. I knew these maps were not for my bike. MPG in the toilet at 36 ish. I was frustrated and about ready to drop major coins for a PC V and autotune ( I still want one).

I was looking thru the map files and saw one of interest, not so many wide swings.

M419-501 2006-2008 Yamaha FJR1300 European model, Stock exhaust, Stock air filter, O2 sensor disconnected

As Dynojet's maps are known to be on the rich side and my mods were going to lean things out I decided to give this one a try for a tank of fuel. Weather had delayed this test ;(

Power is great and smooth across the board, after a tank of mostly spirited riding, I ciphered 41.8 mpg.

I call this a success, I'm not looking for every ounce of HP I can get, I don't want to dump raw fuel on the pavement behind me

I wonder if the Barbarian pin mod puts the ecu in a "European mode" and the base maps are different also?

That would explain my driveability issues with the large mixture swings in all the USA maps.

Please no Dyno advise, that money would make quite a dent in a PC V with autotune lol

Fred W · Aug 9, 2012

To answer your question:

No, installing the barbarian jumper and leaving the CO settings at stock values has no effect on the base fuel map or ultimate fueling.

But, disconnecting the O2 sensor does, as the ECU will run solely on the base map and never go into "closed loop" mode. With the O2 sensor still hooked up, under certain specific circumstances, at idle and steady, low load throttle settings (cruise), the FI will go closed loop. That is when the ECU over-rides the base map fueling by adjusting it based completely on the feedback from the O2 sensor.

Why do the DynoJet maps have swings both positive and negatively? Because they have found (experimentally on a dyno) that the base map mixture on a stock bike is too lean in some places (especially mid - high rpm and mid to large throttle settings) but is actually too rich in others (low-mid rpm larger throttle settings). Modification of intake and exhaust paths will shift the entire map towards leanness, so there are still the same swings, but shifted towards positive numbers.

But how many samples did they take before settling on their map? How many dyno pulls? How much data did they average? Not enough, would be an accurate guess.

Your last statement shows that you already know the answer to your query. The only good way to get an accurate map would be a dyno session on your bike, ideally with wideband sensors installed in your headers. Or you could get a PCV with Autotune,

If you just want to play around with the maps that you already have, you could try mixing maps using the PC3USB program. You just pull two maps into the Map Compare utility and then select the "Average Maps" display. Copy all of the cells there and then paste them into the table on the main settings page. If you average a particular map with the zero map you'll get "half corrections." Average that half map with the original map again and you'll get 3/4 corrections, or with the zero map again for 1/4 corrections. It's a little like shooting in the dark, but eventually you may hit your target somewhere close.

Chuck35 · Aug 9, 2012

Thanks Fred, for taking the time to post

I have experimented with copy and past maps, but didn't know about averaging them. Nice trick!

I'm actually quite pleased with current performance and mpg. When I mess with it again it will probably be PC V and autotune

UselessPickles · Aug 9, 2012

Fred W said:
Or you could get a PCV with Autotune, but to be honest, I'm not sure how well that can work since the Autotune wideband O2 sensor is installed after the cats.

The O2 sensor is before the cats. The wide-band O2 sensor replaces the stock narrow-band sensor. The stock O2 sensor wouldn't work very well either if the bung was after the cats. The cats are right where the 2 separate pipes come out of the collector (going to each of the mufflers; there's a significant bulge where the cats are), and the O2 sensor is more in the middle of the collector.

RadioHowie · Aug 9, 2012

UselessPickles said:
Fred W said:

Or you could get a PCV with Autotune, but to be honest, I'm not sure how well that can work since the Autotune wideband O2 sensor is installed after the cats.

Click to expand...

The O2 sensor is before the cats. The wide-band O2 sensor replaces the stock narrow-band sensor. The stock O2 sensor wouldn't work very well either if the bung was after the cats. The cats are right where the 2 separate pipes come out of the collector (going to each of the mufflers; there's a significant bulge where the cats are), and the O2 sensor is more in the middle of the collector.