Auto Tune on the Power Commander 5 (PC-V)

Kraven that also assumes the A/F instrument functions correctly all of the time. That is the only ? on the autotune for our application. Going to let a few of those tear around before I become their number one advocate. Theory sounds good though!

F-Bomb said:

Kraven that also assumes the A/F instrument functions correctly all of the time. That is the only ? on the autotune for our application. Going to let a few of those tear around before I become their number one advocate. Theory sounds good though!

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Rob...you just make too much darn sense sometimes!:>)

Power commander with autotune has no timing control which is part of what the ethanol switch does. Also autotune is not going to be a feature that is to be run all the time, basically perform a mod, get the pipe and water temps high enough for the ECU to quit making adjustments, then make a few runs and let the autotune make its adjustments, turn off the autotune, and remove the sensor from the pipe. Anyone who thinks that autotune is a put it on and leave it on item hasn't done their research, its a tuning tool to help you dial in your engine and any mods you may have. After a tune has been perfected the autotune is shut off, then the factory ECU opperates as normal and adjusts for altitude and temperature changes while the powercommander intercepts the signal to the injectors and adjusts the signals duration in accordance with the changes that the autotune needed to set the A/F ratio.
The Power Commander has a fixed set of percentage reduction/additions in fuel, the factory ECU still does the thinking sort of like an ATACC on a carbed sled, the jets are the power commander in that they are fixed, the ATACC is the ECU and responds to altitude and temperature changes

fuel boxes

Electrotech, that was an excellent post as I agree with you that fuel boxes are nothing more than an electronic jet wrench. They can only add or subtract fuel.Running good fuel is key along with mixing the correct amount of race gas as needed for your elevation,choice of heads ,compression ratio, twin pipes or single pipe as quoted by Rob from Better Boards.The correct air-fuel ratio number at every RPM on a 2 stroke motor that you give to the pc5-autotune is only known by GOD and he is not telling.A 4stroke will run on a closed loop system with a constant number just fine unlike a 2 stroke. I run O-2 sensors,EGTS and power commanders,and have had some educational experiences causing me to have some reservations about the accurate workability of the pc-5 autotune basing all its tuning capability on the fact that it gathers all its data through a wideband O-2 sensor that in the end can only add or subtract fuel.

I talked with Jim at DTR in depth on this... as well as DynoJet...

Here is my understanding of the unit.

On the 2 stroke sleds.. the Auto tune is a limited use tuning tool and not intended to be used as a full time "closed loop" fuel controller.. The O2 sensor cant be relied upon and needs to be removed from the exhaust stream after tuning has been done

I don't use my autotune all the time but I do watch my AFR on the LCD all the time. 500 miles and all is well so far. It would be cool to have a PDA or Iphone app to be able to "jet for the day" without lugging around a laptop.

Especially in varying elevations, I'd think there would be even more of a benefit to leaving it on all the time, as opposed to the flatlanders.

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The Factory ECU has an "autotune" feature of sorts built in.

It has a Barometric pressure sensor that alters the Fuel AND ignition when chaging elevation... This is the BASE MAP that the PC adds or subtracts fuel (no ignition) from.

I decided to go with the PC V w/ auto tune myself. The auto tune showed up yesterday and the PC V should be here any day. I wanted a way to safely create a map that could compensate for me plugging the exhaust valve solenoid ports. I suspect and am keeping my fingers crossed that there should be some nice mid range gain to be had here.
I am keeping my 08 base mapping as it has never given me an issue and I don't have to worry about plugged or unplugged wires. My plan is to do some test runs as stated and create a usable map for the area I'm riding in. I understand these things have the ability for you to add a switch to simply turn them on and off as well as switch between two maps.
With the ECU doing its job and once you create a usable map on the PC we should see a good improvement regardless of temp and altitude change. At least that is my hope.
Rick,
That's good to hear your o2 sensor is holding up. Surprising, but good. Do you notice that once you use the auto tune and set your mapping that everything stays fairly consistent? I'm excited to try this.


I wanted to go with the CMX unit as he is doing a very similar thing with an O2 sensor. Mark has taken it a step further by allowing you to control upper and lower injectors. He found some interesting stuff about how power is made at certain RPM as well as how the motor cools by where fuel is being fed. Unfortunately, my time is running short and I needed to get a box of some kind. My hat is off to him though for making sure it is 100% right the first time before he puts it in the hands of the public.

Rick! said:

I don't use my autotune all the time but I do watch my AFR on the LCD all the time. 500 miles and all is well so far. It would be cool to have a PDA or Iphone app to be able to "jet for the day" without lugging around a laptop.

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Well the ecu should compensate for daily changes but something you can do along with the 2 maps on the pcv is load some more maps on the lcd

Kraven said:

Eric,

Assuming POLARIS mapped for altitude variations as well as they bungled, 'er uh mapped the current and previous fuel maps, (and re-maps and re-flashes still yet to come) would you rather "trust" POLARIS's map or would you rather rely on what the O2 sensor is "guiding" the fuel controller to do in actual real world conditions???

Just my humble opinion

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hey Kraven, not on the "flat land site" as much?

what you need to do is buy one of these 800's and get your self a pcv with autotune and get working on this. With your energy, I doubt it would take you long to get this solved.

I'm currently running a auto-tune/pc5 on my sled and so far it is working great so far, 12.5 seemed real rich so I set it for 13.0 and it felt better across the rpm range.The map it built is very lean at idle a little lean in the middle and fat on top.I ride at 5-8k elevation.I was a pc tuning center for Harley's from 1998-2007 and I wish they had this technology then it would of made things alot easier

I'm still wondering how all of you guys are determining your current state of tune so that you'll know what fuel variations that you need to introduce to your individual system? A/F and EGT reads vary and mean different things based on application, RPM duration, heat, and load so identifying "ideal" is a wildly random holy grail. Vast experience and effort still appears to be the only legitimate solution and it becomes more mechanical then automatic. The field seat of the pants dyno is just too wanting for the masses and doesn't really give recreational users true value.

Here is my number one important question for those with experience.
... on this application at what variation in altitude, temp, and or air condition have you noticed your sled will effectively perform at prior to needing a mapping change?

IE "my sled is right on the money 5000 ft 23* air moisture content ? I run it up to (????) say 7300 and then it's not as effective...and I require my leaner or adjusted map at that time." Do we get a few thousand feet and 15* average with consistant air density? This is what I want to know.

F-Bomb said:

I'm still wondering how all of you guys are determining your current state of tune so that you'll know what fuel variations that you need to introduce to your individual system? A/F and EGT reads vary and mean different things based on application, RPM duration, heat, and load so identifying "ideal" is a wildly random holy grail. Vast experience and effort still appears to be the only legitimate solution and it becomes more mechanical then automatic. The field seat of the pants dyno is just too wanting for the masses and doesn't really give recreational users true value.

Here is my number one important question for those with experience.
... on this application at what variation in altitude, temp, and or air condition have you noticed your sled will effectively perform at prior to needing a mapping change?

IE "my sled is right on the money 5000 ft 23* air moisture content ? I run it up to (????) say 7300 and then it's not as effective...and I require my leaner or adjusted map at that time." Do we get a few thousand feet and 15* average with consistant air density? This is what I want to know.

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I would say that is the reason for the auto tune. I gives you the ability to create a couple of different maps. Could be handy when riding at 5000ft one day and 10,000 the next. As MH stated your ECU should still compensate for most of that once a solid base map has been created. Although, I'm going to assume riding style and common load on the motor will play a role in the mapping as you stated af and egt temps vary by conditions and riding style.
A person like yourself who is constantly pointing their skis to the sky would probably want to enable the auto tune on the side of the mountain so it can pick up on your riding style and demand you are placing on the motor. I would be inclined to spend some time in the trees.
The auto tune does come with recommended starting points for different RPM ranges. As I stated earlier, injectors fire at different RPM ranges which is also going to dictate different air fuel ratios will probably be required. If I'm remembering right Jim had just done a general 12.5 across the board and noticed an improvement with that alone.
For most people the auto tune is going to be exactly that...an improvement and likely all they will need or want. Fine tuning RPM ranges will likely still be in the hands of the consumer. A person like yourself will still need to keep the lap top handy for a little while. Once a base line map is created for your sled I'm thinking it will only require minimal tweaking for altitude and temp changes. A competitive person such as yourself will be fine tuning to a much more precise level than the recreational rider.

Kraven... The Word "Map" is a loose jargon term that has been applied to the fuel controllers in general..

It is not really a "map" in the PC.. it is a piggyback algorithm based on RPM/Load that operates off of the ECU's true map.....

The ECU / CFi system is Speed/density setup that controls fuel and ignition based off of such inputs as temp(s), TP, RPM, Baro pressure, etc.

The Piggyback boxes "intercept" only the signal to the injectors and "piggyback" a new signal on top...

This notion that the Auto tune is a true "closed loop" system is not accurate. More accurately... it is a closed loop sub system of an open loop operator.

Also, after talking directly with the engineers at Bosch... the MFG of the O2 sensors in the kits... the sensors ACCURACY degrades over a fairly short time with exposure to oil in the exhaust. The sensor will not "FAIL" ... it WILL give inaccurate info to the processor which uses this now inaccurate info to adjust fuel flow. There is no way around this... the sensors are just not compatible with it.

There is no way, in the field to test an O2 for accuracy.... just weather or not

When the O2 sensors fail in the oil rich environment of the 2 stroke sled it happens in a very peculiar way.

It is not possible to do "free air" calibration or butane confidence testing on an oil compromised O2 sensor... These tests are designed for un-compromised sensors.

I believe that the auto tune... which will help dial in the A/F ratio to a desired level is a good tool... but not a replacement for solid tuning practices as F-Bomb points out.(with or without the controller)

The thing that these boxes DO NOT do is adjust another important item... Ignition timing.

Looking at them as "electronic jetting" is probably the best way to view them. Even though the Auto tune has A self-compensation feature... It should not, IMO after talking to Jim and the DynoJet people... be relied upon to run in closed loop on the 2 stroke sleds. Tuning, Yes... Daily operation, NO... again IMO.

Here is a good article on O2 (Lambda) sensor placement, testing etc... some of it applies some doesn't.
http://wbo2.com/lsu/lsuinstal.pdf

My point is when it starts to give inaccurate input to the box.. you will not know about it.

Don't get me wrong... I will probably be running Power Commander 5 with auto tune on my sled this year... solid engineering that is worth a try.

But you can bank on the fact that I'll be running a good EGT gauge with High speed probes to give me a true indication of what is happening in the motor.

F-bombs points are truly valid... and as Kraven points out.. we are really just in the BETA phase of consumer testing of this unit.

F-Bombs tuning experience is top drawer, real world knowledge...We'll see if any of these units in consumers hands meet his standards (wink)

Also... a lot of what is happening with these "boxes" is that tuning is allowed to happen REGARDLESS of the EPA standards... which the factory is shackled by.

Heck, this is, IMO, one of the main reasons that the SLP and Struthers motors run so well when they are a kit with their ECU mapping. All of those "tight spots" for CO, NOX, etc don't have to be taken into consideration AT ALL... unless it affects performance.