Setting-up the PCV-AT for mileage and cooling
#1
03-28-2010, 08:30 PM
Setting-up the PCV-AT for mileage and cooling
I've been wanting to do this for some time, so here it goes. The point of this write-up is to explain how I've configured my PCV with Auto-Tune (PCV-AT) for good gas mileage without taking a hit on performance or cooling. For me one big advantage of the PCV as a tuner option is the ability to easily set-up a map or hardware switch and be able to toggle between two maps. With the basic PCV you can load two distinctly different maps, but this write-up is about setting up the switch with Auto Tune (AT), which is very different in operation. DynoJet calls it a "map switch" for the basic PCV (no-AT) and a "hardware switch" for Auto-Tune. To use Auto-Tune with or without a switch the Map Switch option under Device Tools > Configure must be disabled and to use a switch with Auto-Tune go to the Enable Hardware Switch option under the Auto Tune section and check it. They are two completely different features and you can't use the Map Switch option (two different base maps) with Auto-Tune.
With AT, instead of having two different base maps to choose from you have the option of running the base map in open-loop mode (AT inactive) and that same base map in closed-loop (AT active) using leaner target AFR's. The way I approached it was to create a rich base map for those rare times when you need extra cooling and lean, mileage-optimized Target AFR tables to run on most of the time. Compared to the basic PCV that switches between two different base maps, this effectively accomplishes the same thing when set-up properly, but first let's look at a few fundamentals. The PCV-AT software is divided into three pairs of tables, each representing front and rear cylinders--the base map, target AFR, and trim. There is also one ignition-advance table for both cylinders, but although it it does not auto-tune it retains the bike's on-board knock-sensing capabilities.
Open-loop: No AT, no feedback from the O2 sensors, runs on the base map only. All EFI bikes without O2 sensors
run in open-loop mode.
Closed-loop: AT with feedback from the O2 sensors, writes to the trim tables on the fly.
Base Map: This is the basic map from which the PCV operates.
This is my base map for Cyl. 1. On the x-axis you can see throttle position (TP) and on the y-axis RPM's. If you'll look at 2500 @ 10% TP you'll see a value of "8", which means the PCV is demanding 8% more fuel than the ECM is dictating for that RPM and TP. You have a range of ±100% to work with and can change these values at any time with the PC software. A basic PCV with no AT runs on this base map and that is what dictates the amount of fuel delivered to the injectors, but add AT to the mix and there is more to work with.
Target AFR tables: In these tables, which are exclusive to AT, you provide the AFR's you want to run at a given point. In this example at 2500 @ 10% we see "14.6", and that means I'm telling the PCV-AT to provide an AFR of 14.6:1 at that point. It will take this spec, calculate the actual AFR read by the O2 sensors, then adjust the trim tables at that point until the spec is met. The trim tables interact directly with the base map by adding or subtracting from it, so the trim table is constantly being updated as you ride the bike. The following is the Target AFR table I'm using now for both cylinders:
Note that these targets are equivalent to a stock bike in the cruise range, but since I've installed an oil cooler I can use values without running excessive engine temperatures, most of the time anyway. If you aren't running a cooler you might want to back-off on these values a bit, like maybe to 14.2 or thereabouts. OTOH you still have the ability to switch to the rich base map any time you want, so I would say just go for it and keep a close eye on oil temps during the summer months.
Trim Tables: AT samples at a rate of 50X/sec. from the O2 sensors, so trimming is going on at a very rapid pace. This is another table exclusive to AT and as it reads from the O2 sensors it is adjusting the trim tables on the fly. Again, trims interact with the base map to meter the amount of fuel to the injectors. As an example, let's say the O2 sensors read an AFR of 14.0 at a given point in time and we've asked for 14.6. AT will subtract fuel in the above example by writing adjustments to the trim tables until it meets that spec. Thus for 2500 @ 10% you can see that it is currently trimming at "-17", which means it is subtracting fuel from the base map. If I take a ride and check it later it may show "-14" or something else depending on the conditions. Since the base map has a value of "8" at that point if you subtract -17 you get a net value of "-9". So, the resulting effect is that the PCV is subtracting 9% from the values dictated by the ECM at that point. Note that the trim values cannot be changed except by the AT itself, so you can't go in and arbitrarily change them yourself.
Since my base map is very rich and my target AFR's very lean in the cruise range, you can see the net effect by all the negative numbers being generated by AT.
Ignition table: This is one table that affects both cylinders, and you have ±10° to work with. This table does not auto-tune, so the values need to be inserted based on either a dyno tune or values known accurate for that model and hardware configuration. The values used above 60% TP were in the original Fuel Moto map and I added some advance to the cruise range, but this may not work well for other applications. Oddly, I could not add any advance in this area with my stock cams installed.
Now, how to configure this thing to provide optimal mileage without overheating or incurring other adverse side-effects? The first step after installing AT and making sure it works properly is to install a hardware switch. This can be any on-off switch, like the ACC switch already on most bikes or something you might buy at Radio Shack for a few bucks. All you need is a switch that provides an open and closed circuit at your demand. If you use the ACC switch on the bike you will need to remove the P&A fuse that powers it, as the switch cannot have any 12V power going to the PCV. Note that this works for '07 and maybe earlier, but at least as far back as '09 the P&A fuse also feeds the lighter and heated grips. For those bikes it may be necessary to add a switch, or cut the O/R wire at the switch and splice another wire to run under the tank. I am using a second ACC switch installed in the left side of the switch panel under the radio, as the original ACC switch is currently used for heated clothing.
When the switch is closed (normally "on" position) you will be running in AT (closed-loop) mode and when open it will be running the base map (open-loop) with no feedback or trimming taking place. The trick is to create a rich base map to start with, and you do that by temporarily inserting abnormally rich values in the target AFR tables. Here are the values I used:
Start out with whatever base map you have, configure the Target AFR tables as in the above example or to your own specs, then take the bike out for a long ride through all RPM and TP ranges repeatedly. By doing this you create an accurate trim table for your bike. Once this is done, go in your PC software to Power Commander Tools > Configuration > Auto Tune, then click on "Accept Trims." What this does is write the trim tables to the base map, thus creating a new base map. So, if I did this with the above example my value at 2500 @ 10% TP (8%) would be trimmed (-17%) and a new value of "-9" would be written to the new base map. It does this for all cells in the tables and once this is done the trims are zeroed and you start trimming again from scratch. The next step is to change some of the values in the Target AFR tables to create a whole new configuration from which AT will run most of the time.
Now, forget this rich table and refer back up to the first Target AFR table above. For mileage, I've gone with rather lean settings in the cruise range (2000-3000 RPM @ 5-15% TP) and tapered these values out to 60% TP. I have not changed any values above 60% TP, but have fooled around with those above 3000 RPM's as you can see. What I want to accomplish is to get optimal gas mileage at part-throttle (cruising) and still have the rich AFR's when I roll it on to pass a truck, so the Target AFR table above with the leaner values will do both, but there's a catch. Run it lean and it will run hotter, and that's where the switch comes into play. When the going gets slow and you see oil temps start to climb, switch to open-loop and you'll then be running the rich base map to cool things down. This works well, but don't expect it to be instantaneous or a panacea, as it will take time for the richer mixture to translate into reduced head and oil temps and obviously won't keep the temperature down indefinitely when you're not moving. I try to anticipate hot running and switch to open-loop before the temperatures start to climb, but you obviously can't always do this.
Keep in mind that DynoJet recommends not inserting any Target AFR values at 0% TP. To do this simply insert "0", which tells AT to run the base-map value without change. The "-10" values used at 0% from 3000 RPM and above were in my original Fuel Moto map, and since I'm having no decel-popping problems I've left these alone. After adding the 255 cams I did notice that I was getting an over-rich condition at 0% just above idle, so I temporarily inserted "14.5" at 0% up to 2750 RPM and ran the bike to create some trims in that range. I then removed the targets and added the resulting trim values to the base map, as you can see, which corrected the over-rich condition. Be advised that if you do this the trim values will not change and you will need to "Clear trims" to get them back to zero. If you don't you'll be running the adjusted values in the base map and another adjustment in the trim tables, and that means you're doubling the effect. I also am using "0" at 1250 RPM from 0-10% TP, which is another adjustment I needed to make with the 255 cams.
This has worked well for me so far, and my gas mileage is quite good while being able to adjust to hot running when needed. Please comment on errors and other ideas, as I'm anxious to hear what y'all have come up with.
With AT, instead of having two different base maps to choose from you have the option of running the base map in open-loop mode (AT inactive) and that same base map in closed-loop (AT active) using leaner target AFR's. The way I approached it was to create a rich base map for those rare times when you need extra cooling and lean, mileage-optimized Target AFR tables to run on most of the time. Compared to the basic PCV that switches between two different base maps, this effectively accomplishes the same thing when set-up properly, but first let's look at a few fundamentals. The PCV-AT software is divided into three pairs of tables, each representing front and rear cylinders--the base map, target AFR, and trim. There is also one ignition-advance table for both cylinders, but although it it does not auto-tune it retains the bike's on-board knock-sensing capabilities.
Open-loop: No AT, no feedback from the O2 sensors, runs on the base map only. All EFI bikes without O2 sensors
run in open-loop mode.
Closed-loop: AT with feedback from the O2 sensors, writes to the trim tables on the fly.
Base Map: This is the basic map from which the PCV operates.
This is my base map for Cyl. 1. On the x-axis you can see throttle position (TP) and on the y-axis RPM's. If you'll look at 2500 @ 10% TP you'll see a value of "8", which means the PCV is demanding 8% more fuel than the ECM is dictating for that RPM and TP. You have a range of ±100% to work with and can change these values at any time with the PC software. A basic PCV with no AT runs on this base map and that is what dictates the amount of fuel delivered to the injectors, but add AT to the mix and there is more to work with.
Target AFR tables: In these tables, which are exclusive to AT, you provide the AFR's you want to run at a given point. In this example at 2500 @ 10% we see "14.6", and that means I'm telling the PCV-AT to provide an AFR of 14.6:1 at that point. It will take this spec, calculate the actual AFR read by the O2 sensors, then adjust the trim tables at that point until the spec is met. The trim tables interact directly with the base map by adding or subtracting from it, so the trim table is constantly being updated as you ride the bike. The following is the Target AFR table I'm using now for both cylinders:
Note that these targets are equivalent to a stock bike in the cruise range, but since I've installed an oil cooler I can use values without running excessive engine temperatures, most of the time anyway. If you aren't running a cooler you might want to back-off on these values a bit, like maybe to 14.2 or thereabouts. OTOH you still have the ability to switch to the rich base map any time you want, so I would say just go for it and keep a close eye on oil temps during the summer months.
Trim Tables: AT samples at a rate of 50X/sec. from the O2 sensors, so trimming is going on at a very rapid pace. This is another table exclusive to AT and as it reads from the O2 sensors it is adjusting the trim tables on the fly. Again, trims interact with the base map to meter the amount of fuel to the injectors. As an example, let's say the O2 sensors read an AFR of 14.0 at a given point in time and we've asked for 14.6. AT will subtract fuel in the above example by writing adjustments to the trim tables until it meets that spec. Thus for 2500 @ 10% you can see that it is currently trimming at "-17", which means it is subtracting fuel from the base map. If I take a ride and check it later it may show "-14" or something else depending on the conditions. Since the base map has a value of "8" at that point if you subtract -17 you get a net value of "-9". So, the resulting effect is that the PCV is subtracting 9% from the values dictated by the ECM at that point. Note that the trim values cannot be changed except by the AT itself, so you can't go in and arbitrarily change them yourself.
Since my base map is very rich and my target AFR's very lean in the cruise range, you can see the net effect by all the negative numbers being generated by AT.
Ignition table: This is one table that affects both cylinders, and you have ±10° to work with. This table does not auto-tune, so the values need to be inserted based on either a dyno tune or values known accurate for that model and hardware configuration. The values used above 60% TP were in the original Fuel Moto map and I added some advance to the cruise range, but this may not work well for other applications. Oddly, I could not add any advance in this area with my stock cams installed.
Now, how to configure this thing to provide optimal mileage without overheating or incurring other adverse side-effects? The first step after installing AT and making sure it works properly is to install a hardware switch. This can be any on-off switch, like the ACC switch already on most bikes or something you might buy at Radio Shack for a few bucks. All you need is a switch that provides an open and closed circuit at your demand. If you use the ACC switch on the bike you will need to remove the P&A fuse that powers it, as the switch cannot have any 12V power going to the PCV. Note that this works for '07 and maybe earlier, but at least as far back as '09 the P&A fuse also feeds the lighter and heated grips. For those bikes it may be necessary to add a switch, or cut the O/R wire at the switch and splice another wire to run under the tank. I am using a second ACC switch installed in the left side of the switch panel under the radio, as the original ACC switch is currently used for heated clothing.
When the switch is closed (normally "on" position) you will be running in AT (closed-loop) mode and when open it will be running the base map (open-loop) with no feedback or trimming taking place. The trick is to create a rich base map to start with, and you do that by temporarily inserting abnormally rich values in the target AFR tables. Here are the values I used:
Start out with whatever base map you have, configure the Target AFR tables as in the above example or to your own specs, then take the bike out for a long ride through all RPM and TP ranges repeatedly. By doing this you create an accurate trim table for your bike. Once this is done, go in your PC software to Power Commander Tools > Configuration > Auto Tune, then click on "Accept Trims." What this does is write the trim tables to the base map, thus creating a new base map. So, if I did this with the above example my value at 2500 @ 10% TP (8%) would be trimmed (-17%) and a new value of "-9" would be written to the new base map. It does this for all cells in the tables and once this is done the trims are zeroed and you start trimming again from scratch. The next step is to change some of the values in the Target AFR tables to create a whole new configuration from which AT will run most of the time.
Now, forget this rich table and refer back up to the first Target AFR table above. For mileage, I've gone with rather lean settings in the cruise range (2000-3000 RPM @ 5-15% TP) and tapered these values out to 60% TP. I have not changed any values above 60% TP, but have fooled around with those above 3000 RPM's as you can see. What I want to accomplish is to get optimal gas mileage at part-throttle (cruising) and still have the rich AFR's when I roll it on to pass a truck, so the Target AFR table above with the leaner values will do both, but there's a catch. Run it lean and it will run hotter, and that's where the switch comes into play. When the going gets slow and you see oil temps start to climb, switch to open-loop and you'll then be running the rich base map to cool things down. This works well, but don't expect it to be instantaneous or a panacea, as it will take time for the richer mixture to translate into reduced head and oil temps and obviously won't keep the temperature down indefinitely when you're not moving. I try to anticipate hot running and switch to open-loop before the temperatures start to climb, but you obviously can't always do this.
Keep in mind that DynoJet recommends not inserting any Target AFR values at 0% TP. To do this simply insert "0", which tells AT to run the base-map value without change. The "-10" values used at 0% from 3000 RPM and above were in my original Fuel Moto map, and since I'm having no decel-popping problems I've left these alone. After adding the 255 cams I did notice that I was getting an over-rich condition at 0% just above idle, so I temporarily inserted "14.5" at 0% up to 2750 RPM and ran the bike to create some trims in that range. I then removed the targets and added the resulting trim values to the base map, as you can see, which corrected the over-rich condition. Be advised that if you do this the trim values will not change and you will need to "Clear trims" to get them back to zero. If you don't you'll be running the adjusted values in the base map and another adjustment in the trim tables, and that means you're doubling the effect. I also am using "0" at 1250 RPM from 0-10% TP, which is another adjustment I needed to make with the 255 cams.
This has worked well for me so far, and my gas mileage is quite good while being able to adjust to hot running when needed. Please comment on errors and other ideas, as I'm anxious to hear what y'all have come up with.
Last edited by iclick; 06-04-2012 at 05:44 PM.
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julesdain (11-22-2016)
#2
03-29-2010, 08:04 AM
Road Warrior
Well written. I have done exactly the same thing. The only differences for my maps is that I use 14.2 AFR where you have the 14.6 since I dont have an oil cooler. The other difference is that I dont use any values in the ignition table except in the abouve 60% range since I have the stock cams.
Good writeup.
Good writeup.
#3
03-29-2010, 08:18 AM
#5
03-29-2010, 05:52 PM
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#6
03-30-2010, 11:26 AM
Keep us posted on your progress. Before making the cam upgrade I had my bike running well at 14.7:1 in the cruise-range, so you might be able to bump it up a bit. But watch oil temps if you don't have a cooler. Where I have it now, 14.5-14.6 works well in my bike with the 255's, and mileage is in the upper end of what people are reporting here.
#7
03-30-2010, 01:50 PM
Road Warrior
I tried AFRs from 13.5 - 13.8 and ended up leaving it at 13.8. I didn't really see the benefit at 13.5 so I run it at 13.8 now. Got the cooling and saved a little gas. I plan to monitor it on the hotter days this summer.
Last edited by JustDennis; 03-30-2010 at 01:53 PM.
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#8
03-30-2010, 03:52 PM
I thought with the auto tune you could set a map for every gear, is this something you can do yourself or a specific option for a dyno tuner. If you can set a map for each gear cant you leave 1st and 2nd maybe 3rd gear rich and lean out you cruising gears. Would this help with fuel mileage also? That is if its even possible.
#9
03-30-2010, 07:12 PM
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I thought with the auto tune you could set a map for every gear, is this something you can do yourself or a specific option for a dyno tuner. If you can set a map for each gear cant you leave 1st and 2nd maybe 3rd gear rich and lean out you cruising gears. Would this help with fuel mileage also? That is if its even possible.
This can be done with the PCV either on the dyno or with the AT using the dynojet software. I have not tried it though....
#10
03-30-2010, 07:58 PM
Road Master