Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
(OP)
Hi, I'm about to purchase a fuel map device for my Hypermotard.
As background, the stock system has a single O2 sensor located after the two header pipes come together which provides a signal for closed loop feedback at low throttle and rpm. (<20%throttle, <5,500rpm). Above this range the stock system then goes to map based open loop.
My new device (Power Commander V) will not change basic process for low throttle operation, but will move the map base a little more rich. For higher throttle/rpm, the new device will have an autotune capability, whereas the signal from an additional O2 sensor(s) will be used to automatically develop the fuel map to a predefined air/fuel ratio map.
My question is whether it is considered that the fuelling needs of the two cylinders are likely to be different enough (due to temperature difference etc..) that I should have two sensors, one for each cylinder, or if one would be sufficient. My concern would be that if the difference between the fueling needs of the two cylinders is significant, with one sensor I'm running an average - ie one cylinder rich and one lean. Cons of two sensor setup are cost and complexity - I'd need three O2's - the stock one plus one in each header.
Thanks, Andrew
As background, the stock system has a single O2 sensor located after the two header pipes come together which provides a signal for closed loop feedback at low throttle and rpm. (<20%throttle, <5,500rpm). Above this range the stock system then goes to map based open loop.
My new device (Power Commander V) will not change basic process for low throttle operation, but will move the map base a little more rich. For higher throttle/rpm, the new device will have an autotune capability, whereas the signal from an additional O2 sensor(s) will be used to automatically develop the fuel map to a predefined air/fuel ratio map.
My question is whether it is considered that the fuelling needs of the two cylinders are likely to be different enough (due to temperature difference etc..) that I should have two sensors, one for each cylinder, or if one would be sufficient. My concern would be that if the difference between the fueling needs of the two cylinders is significant, with one sensor I'm running an average - ie one cylinder rich and one lean. Cons of two sensor setup are cost and complexity - I'd need three O2's - the stock one plus one in each header.
Thanks, Andrew





RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
Although the fuel demands won't be identical, they're unlikely to be different enough to be meaningful. The engine still has a separate throttle per cylinder, and that overwhelms all tuning effects at part throttle. It has a separate intake runner per cylinder drawing from a common plenum ... at full throttle, the effects of that plenum will be a fraction of what the individual runner tuning does, and those are the same for both cylinders.
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
Cheers
Greg Locock
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RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
I haven't used a PC autotune on a vehicle that was originally equipped with an OEM O2 sensor. It should come with a means of eliminating the OEM sensor so that you only need one sensor (the wide-band) in the exhaust system.
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
The posted replies suggest to me that the stock system likely has different high end maps for the two cylinders, and also that the Power Commander makes its change as a delta from the base map. Putting these two together implies to me that I'll still have the stock fuelling difference with the new set up.
The instructions on the Autotune imply the ability to select AFR from 12 to 14.7, apparently confirming Brian's last comment.
Based upon this, it appears the one sensor Autotune is an effective route. Thanks for the help.
Brian, I can get to one sensor but that requires to have the stock ECU reflashed to change it to open loop so that the Power Commander drives the full range. However, on my bike, the stock set-up does a decent job at cruise, albeit feeling a little lean, and so I don't really want to change it. I haven't seen any options that allow the stock ECU to use the Autotune sensor.
Given the helpful replies so far, I'll share what I'm up to in case there are better ideas. All I want to do is to remove the CAT. By doing this I can save some weight and let the engine breath a little more easily - as an engineer, a win/win. However, as the stock system is open loop at high RPM, I will be adding more air to a system tuned to run pretty lean already, and it will not adjust for it. Other have tried the mod without any fueling changes and the plugs have shown it runs lean. What would you do ?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
"If using Auto-tune, you need to make sure that Auto-tune is disabled in the stock closed loop range to keep the Auto-tune O2 sensors from fighting with the stock O2 sensors. You do this by entering a Target AFR of zero (0) in the stock closed loop range. You will notice that all of our predeveloped map files for the bike model are already setup like this.
You need to keep the stock O2 sensors in the exhaust and active. If you are adding Auto-tune you would need to add additional O2 sensors, but the stock sensors will still need to be in the exhaust. We have no way to eliminate the stock O2 sensors, short of reprogramming the stock ECU."
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
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RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
http://www.tuneboy.com.au/buy.html
These guys are pretty good to deal with. I've used their stuff on my Triumph, worked great.
If you are concerned about the cost of doing the autotune with multiple sensors, can you just tune 1 cylinder at a time, and swap the sensor between the 2 pipes?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
The piggy back systems like Power Commander are very crude by comparison. You have to splice into the wiring harness and the things that you can control are limited.
There is a freeware competitor to TuneBoy called TuneECU but I don't think they support Ducs at this time.
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
The selling feature for a bazzaz(to me) is the shift kill feature. I have a CBR1000RR with their full setup. And a Z1000 with a full PC+ignition module. But for efficiency of execution, you won't be able to beat the leaving the factory ECM in control and remapping it with the Tuneboy.
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
Thanks to bradrs and dgallup for the lead.
I do have one question from all my research. This map based fuel injection system is commonly referred to as "Alpha-N". This gives a single map value for fuel dependent only upon TP and RPM. However, I expect the fueling requirement at a specific TP/RPM is different under acceleration, steady state and slowing. I have found in my research devices which claim that Alpha-N strategy does not account for these differences, and that a load based modifier is necessary ( EJK electronicjetkit.com for example). My suspicion is that the claim is technically correct - ie pure Alpha-N strategy does not in itself allow for this, but I also expect that the motorcycle ECU has a strategy above pure Alpha-N that compensates - ie nobody is actually running pure Alpha-N. For example, I've read that the fuel is cut when the throttle is shut - which would not occur under pure Alpha-N. Does anyone know what the motorcycle ECU typically does to adjust the map for load when running Alpha-N ?
(In case it's of interest my ECU is the Marelli 5AM.)
Thanks, Andrew
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
I am able to build a target AFR map in Tuneboy, which the Tuneboy software will then generate a new fuel map that it expects will give the desired AFR. However, I'm not sure what I want to use as targets.
I suspect this question may be akin to "how long is a piece of string" (dependent on engine and performance goal variables), but knowing that I am running the Ducati 2 valve 1100, stock other than inlet/exhaust mods (no CAT), can anyone recommend suitable AFR targets ?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
For a ruff guess, try 14:1 or thereabouts with throttle position below 20%, 12.8 or thereabouts at 50% throttle and above, and smoothly blend them in between. It is distinctly possible that you will get a rough, unstable idle. If that happens, add a little more right down at idle speed and throttle.
On a liquid-cooled engine you can run "lean cruise" for better fuel economy, but without EGT and/or cylinder head temperature monitoring, I'm not sure I'd try it in your case. Below 20% throttle, there is so little load on the engine that it shouldn't be a problem.
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
Thanks for the comment - it seems very logical to me and in line with my own thinking. At the bottom end, the bike stock (with CAT and closed loop control)ran OK but was always notchy/digital/jumpy at small throttle, and the extra fuel it has now has certainly smoothed that out, but I think it is more than needed. I'll move that to 14 and then adjust a little if I see that issue coming back. For mid range/cruise I will lean it up as I have lost some tank range - a significant concern as the tank is small. I'll move high end to 12.7.
I'm aware that modern engines with appropriate designs, materials and controls run much leaner than this, which is why I particularly appreciate your focused response. Thanks for that.
BTW I'm logging invidual cylinders now (conveniently the later 1100 models have twin 02s so it was an easy header swap to gain the wide band mounting points), and will initially use the same AFR target for both cylinders to see where the fuel maps come out. I know what the frt/rr fuel map delta was stock ( rear gets a litle more fuel ) and I will compare that with what I get after tuning. I suspect I might then have to give the rear some more fuel, to keep it cool.
Andrew
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
RE: Ducati 2 Valve 1100 - Individual Cylinder Fuel maps?
I have Tuneboy, and yes I can change ignition too, but I haven't changed it at all. I've talked to the local dyno guys, and they had suggested I build a few maps that run well and then make a run with each of the maps to see which is best. ( They don't want to use Tuneboy to tune real time on the dyno).
However, I'm not out for the last ounce of performance, so I'm going to just use the AFR gauge/data, my butt dyno and fuel economy to set my direction.
BTW I have my maps set up and loaded as per AFR targets recommended by Brian. The bike runs great, and is revving at high end more eagerly now. Fuel efficiency is back to what it was before I started playing, so life is good and I can get back to riding.
Thanks to all for the input.
Andrew