TuneEcu Maps Explained

[wjb]

DDT, you are our new best friend!

 

[warp9.9]

Mickeys big mouths?

That and some fine corn for medicinal purposes. It sucks mowing one armed but I figure it will suck worse after they cut me open tomorrow for a left side upgrade

 

[Fingers]

Best of luck with the operation

 

[Jag]

That and some fine corn for medicinal purposes. It sucks mowing one armed but I figure it will suck worse after they cut me open tomorrow for a left side upgrade

Good luck tomorrow!

 

[Kevin frazier]

That and some fine corn for medicinal purposes. It sucks mowing one armed but I figure it will suck worse after they cut me open tomorrow for a left side upgrade

be blessed brother

 

[warp9.9]

be blessed brother

Thanks but I'd rather you pray for the surgeon he is the one thats doing the work I just got to lay around.

Anyway bud made it thru already pondering how long before I can start fixing things, or is it a good excuse to either buy another extra one or one or maybe a Speed Twin 1200 for the weight savings and time
Anyway thanks for keeping a eye on me in the woods, my cellmate likes goats. And we were in WBGV

 

[barbagris]

"Odd" is an understatement.

From your Curry-ness, I take that as pure compliment!.

 

[Nexus9]

almost all modern engine management systems work similarly, with certain aspects specific to the type of algorithms they are implementing.... they all however, aim to calculate the correct pulse width of the fuel injectors to supply the amount of fuel to reach the desired AFR/Lambda that's been programmed. Alpha-N systems look at TPS and RPM to do most of the figuring. Speed Density systems look at MAP and RPM, MAF systems look at air mass and RPM.

they *all* need to have an idea of how much air is going into the engine at any given time, engines are just air pumps and the ecu is controlling how much fuel to add to get the right mixture that it's been told to try and hit.

in a speed density system like what is on the Rocket III, (some people may argue it's Alpha-N because it uses TPSvRPM fuel map, but you can call it a hybrid system if it makes you feel better, it does use MAP to figure the L map, and internally probably uses MAP during the F calculation as well, we just don't have it available to us), the tables that describe mostly how much air is going in are the F tables which would be (at least what most people would call) Volumetric Efficiency tables. Basically, 'How much air volume gets into the cylinder at what TPSvRPM?' a VE normalized to 1 (100% full), would be the exact displacement of the individual cylinder/combustion chamber at BDC. at low throttle openings, the engine isn't very efficient and the VE is much below 100%. at higher RPMs and throttle openings, the engine is much more efficient and can often reach over 100% VE. this is very much influenced by the engine design and the camshaft profile, intake opening/closing points, exhaust overlap, etc. at higher RPMs and WOT, VE often falls off again because the engine can't fill the cylinders 100% in the short amount of time that the intake valves are open.
so, if the ECU knows the airflow modeling of the system, then the displacement times the VE times the density of the air as measured by the MAP sensor and the Inlet Air Temperature will tell the ECU how much oxygen is in the cylinder right now. the ECU will then look up the desired AFR for the current TPS/RPM, then based on the known flow rate or injector size (which is coded in the ECU someplace, and it may also monitor fuel pressure or battery voltage to know whether the injectors will be opening at the spec the code was designed for.... low battery voltage can mean low fuel pressure for example) it knows how long to keep the injectors open. at lower AFRs it holds them open longer. with larger injectors or higher fuel pressure it holds them open less, etc.
closed loop operation with narrowband O2 sensors only works in a small range of Lambda/AFR, typically 14.5-14.7 or so, anything outside of that range and the feedback is meaningless because the sensor can't accurately measure outside of that range. So, if your AFR table isn't 14.5 (what appears to be the 'closed loop' switch for this ECU), then the system only uses the parameters i spoke of above to calculate the fueling. in closed loop, it does the same calculation, but there's an additional 'offset' added or subtracted to the fuel timing based on the O2 sensor's feedback. this is most often used to fill out long-term and short-term fuel trim tables. the O2 sensor is giving the ECU a 'trend' to update these tables and they are used in the calculation of the fuel timing. what narrowband O2 sensors won't do (which is often the misconception) is adjust your tune for changes in airflow, displacement, camshafts, etc. if it's not *too* far off it can adjust somewhat, but it's not the intention. it's mostly there for fuel economy and to adjust to slight differences in fuel quality/blends over the course of the riding season/conditions, etc.
for the R3 and TuneECU, you have the 3 F maps which are TPS/RPM VE tables. higher numbers mean higher VE and therefore more fuel will result. the L maps are VE tables, just based on MAP feedback rather than TPS. if you set the F-L switch to 0, you're essentially turning it into an Alpha-N system (presuming the MAP reading doesn't contribute too terribly much to the F map-based calculations. if you set the F-L switch to 100 (if you were able to) you would essentially disable the F map and it would be a pure speed density system using MAP vs RPM VEs that are in the L table.

to tune the VE tables properly (at least, using the typical UEGO tools available), you need to be able to correlate the AFR readings with the engine data. Narrowbands are not the best choice for this, as the range they are effective in is small as stated above..... sometimes this can be fudges somewhat by changing the voltage bias offset to the narrowbands.... while they will still think that they are reading the 14.5-14.7 range, the bias is making them actually sense a higher or lower AFR range. however, this accuracy gets worse the farther away from the normal operating (0 bias) they are designed for. if this capability isn't present in the ECU or tuner software it doesn't matter. tuning with narrowbands basically means setting the entire AFR table to the closed loop region and recording the engine data and applying the offsets calculated to the VE tables. if you are too far away from an accurate VE table, the sensors won't be able to read the AFR accurately and your data is garbage. what typically is done when you have the tools (a dyno is nice for this!), is to use WBO2s to read a range of AFRs that can be as low as 10 to as high as 18 or so. the problem with WBO2s is that their response time is *much* slower than narrowbands. you need to collect a lot more data in steady state conditions with widebands to get a good quality of data. for road testing, setting the AFR table to a fixed, safe value across the board (say 13.x) is often done, to remove the need for the ECU to do a rolling calculation of the AFR as the engine moves to different cells in the VE table while riding (it's hard to keep steady-state operations during road testing). the ECU will typically apply an algorithm to determine the VEs at each point between the cells in the VE tables, it's not simply a 'step-function'. if the cell at 10TPS for a given RPM is 5000, and the 15TPS is 6000, the ECU is will use the surrounding values to figure out what the VE is for 12.5% TPS for example..... having smooth transitions between the values in the VE table is beneficial to the ECU because it minimizes the errors in the perfect calculation (which will never be perfect in the dynamic system). smooth transitions are achieved by having good accurate data.

there's tons of other things that go into the ECU's calculations as well, IVO/IVC, EGR (from cam overlap), the 'imperfectness' of injector flow at low and high duty cycles, the possible nonlinearity of the MAP sensor(s) at different RPMs, etc. One thing i find interesting in this ECU is that they didn't use MAP for timing instead of TPS. Does the Rocket 3 only have 1 MAP sensor or are there 3 indivdual sensors per intake?

timing is a whole other thing that i can give input on as well in a separate post if someone's interested in my thoughts on it.

Hallelujah! Bumping an old thread here, but there has been a wealth of information about this new Tune ECU tuning tool I would like to use. DDT, as I went through 5 pages of this thread, I was waiting for someone to lay down the basic concepts that make everything else so much easier to understand. Thanks for your input. And yes, I would love to read (learn) anything you would like to say about ignition timing tables!
My experience is with TTS Mastertune (Harleys) and HP Tuners (Corvettes). My goal (and, I think, the biggest area of improvement on these bikes) is to move the super lean closed-loop areas of the AFR table closer to 13.8/1 to prevent the missing/surging at smaller throttle openings. Questions are:
1. Does Tune ECU offer any data logging segment that would help us accurately modify the Volumetric Efficiency tables (F&L) if we make modifications that might affect airflow (better flowing mufflers, open airbox, cams etc)?
2. In TTS Mastertune, if I change a cell in the AFR table to be anything other than 14.7 (14.5 in Tune ECU), it removes that cell from closed-loop configuration (which is why the VE tables need to be accurate), basically turning that cell into a carburetor jet. Is this true for Tune ECU as well?
3. If I want to maintain ECU control with the closed loop, but not run as lean, I would normally have an O2 Bias Voltage table. On my '01 BMW R1100RT (non programmable ECU) I use an AF-XiED wired in series with the O2 data signal. Both modify the voltage from the O2 sensor to the ECU to cause the ECU to add slightly more injector timing in closed-loop mode, effectively allowing ECU control, but at 13.8-14.0/1. Is there an O2 Bias Voltage table in Tune ECU?
Thank you for any input/knowledge. Jon

 

[Claviger]

1: No.
2: Sort of, depends on if you leave the o2 sensor enabled. Keihen ECUs don't constantly use closed loop, only in specific sections where the narrowband target table is set to a tight range (can't recall exactly what, like 14.3-14.7 or something like that). It then applies these correction factors to the whole table. The ability to adapt is primitive and essentially non-functional on anything besides a stock bike.
3: There is no O2 bias table in TuneECU, its very basic software, essentially a GUI for a hexeditor with encryption defeat and IO management, that's it. While the functionality to adjust base sensor voltage ranges and values no doubt exists in the ECU itself, it's not been located in the hex file so no interface to adjust it is provided.

EDIT: THAT SAID.... if one were inclined to do some Ohms law math, one could use a small circuit to create a pullup that slightly raises the sensor output voltage received by the ECU, meaning, it would cross the switch point at a richer AFR.

- Further:
The Keihen O2 system control is absolute trash compared to more modern systems, ignore it. You will always a have the best results by disabling the O2 sensor in TuneECU and getting a proper tune. The stock ECU targets Lambda of 1.0, pretty much everywhere, it's a lean burn design for emissions. If you tune it and leave the O2 enabled it will continuously adjust and over time work its way back towards Lambda of 1.0 as long as the adjustment required is within the adjustment range of the ECU. There is no scenario where the O2 enabled is better with a custom tune, even for emissions control checks in MOT or CA annual testing, as the O2 being disabled does not trigger a ready warning, it fully disables the circuit and check for it. That includes a wideband using a narrowband simulated 0-1v output. The simulated output will only help the ECU counteract your custom tune.

 

[Claviger]

there's tons of other things that go into the ECU's calculations as well, IVO/IVC, EGR (from cam overlap), the 'imperfectness' of injector flow at low and high duty cycles, the possible nonlinearity of the MAP sensor(s) at different RPMs, etc. One thing i find interesting in this ECU is that they didn't use MAP for timing instead of TPS. Does the Rocket 3 only have 1 MAP sensor or are there 3 indivdual sensors per intake?

timing is a whole other thing that i can give input on as well in a separate post if someone's interested in my thoughts on it.

2.3 R3s use a single map sensor with timing identification to find a home signal so it knows when #1 is at TDC on the compression stroke. It then knows the next pulse is #2 and the next after that is #3, this is why R3s will always rotate the engine at least 3 times firing on the 4th rotation after a power cycle before firing. It looks for crank position trigger for TDC then for the pulse from #1 within a time window after TDC to identify #1 cylinder. It's quite sloppy about home signal timing too, otherwise a built motor like mine wouldn't work with stock ECU with very not-stock MAP signal pulse size and timing.

It does not use MAP for timing (or fuel in F tables much) because it's a large bore ITB setup, 52mm at the throttle plate. Large bore ITBs have too little MAP variance at low openings and reach atmo pressure quickly, but well before full throttle. As a result the resolution is terrible, thus Alpha-N. You can call it hybrid if you it makes you feel better, but with F-L Switch table set to 0, the L tables have less than 1% influence on the fueling, aka straight up Alpha N. A few members and I went through a lot of work trying to improve the hybrid functionality by blending L and F crossover values, it's terribly finnicky and not at all worth the effort, a clean Alpha-N tune just plain works better.

You need 3 sensors to run a 2.3 R3 engine:
Map sensor
TPS sensor
Crank sensor

The others can be disconnected and the bike will still run, IAT/CLT/BARO/VSS/2nd Throttle TPS. Not only will it still run, it'll still run with no constraints on RPM etc. It's a dumb system that is the very epitome of garbage in garbage out; if you give it bad values in the table, you'll get bad values from it, if you give it good values, you get good results. For those who have their bikes tuned, it's great in a way, it does exactly what you tell it, but that's also a constraint as it's limited to the temp/baro correction values the factory hardcoded into it (and those values are not correct with 2.3 R3s routinely growing progressively more lean as air temperatures rise beyond 90f).

All this is why I'm going to a standalone, I'm sick of an awesome engine being hamstrung by an ECU that would be the very left end of the bell curve if one existed for ECUs. It is a solid ECU for its era, but that era was 25 years ago and motorcycle tech was 15 years behind automotive tech so it's really more like the TPI computers from the 80s than anything else.

About 5 minutes in he explains why MAP control is a bad option for ITB engines. The bigger your cam the worse the effect as starting vacuum levels are lower, thus MAP resolution is lower.

Sneaky edit:
This is why someday, I'll own my own dyno, so I can demonstrate this stuff.