Why Install an AFR Tuner?
(12Jul11)

The fuelling on the 900 & 1130 is good at high revs, but less than perfect at mid to low revs, where it spends most of it's time in everyday use. Perhaps this is due Benelli's choice of injectors, noise or emissions requirements, the ability of the ECU, it's track oriented heritage, or maybe they just got it wrong. This has been discussed on the Benelliforum in the past, and no doubt will surface again.
I installed a wideband oxygen (lambda) sensor to the exhaust, and took some air/fuel ratio (AFR) data, using an Inovate LM-1, under various conditions, and discovered that my 900 was running very rich at low revs, which was causing the plugs to foul. At around 6,000 rpm, & fast cruising, the fuelling was just about at stoichiometric. No surprise that that was where it delivered it's best economy.
The challenge was to correct the fuel map, improving the reliability of the bike & it's endurance. I was sick of being the one who forced a fuel stop on everyone. (The 1098 is now the but of all the jokes!)

How do you change the fuel map?
A couple of possibilities :-

  1. Download a new map to the ECU, using a tool that talks to it, via the diagnostic connector. That tool could be the Axone 2000, or a laptop running Tuneboy, or similar application. These tools can also read & reset any error flags that the ECU has logged.

    Axone 2000
    Axone is the standard tool used by Benelli, and several other manufacturers. It's ~$2000 & not that easy to come by. It can talk to many different ECU's though, if you have the right interface cable & installed software.
    TuneBoy Default Screen Tuneboy Sensors Window
    Tuneboy works similarly to Axone. It runs as an application on a PC, and talks to the ECU with a special RS232 or USB cable, but it is locked to a single ECU serial number. Certain variants are a bit smarter than the Axone though, as they can also take engine data, such as throttle position & rpm, and external data from a wideband O2 sensor, which, with the correct equation, will provide the air/fuel ratio (AFR). With this setup, you can modify your own injector timing (fuel) map.
  2. Or, you can bypass the map in the ECU, and add a fuel controller between the ECU injector outputs, and the injectors themselves. This controller is given it's own fuel map. The ECU triggers the injector pulse, but the controller inserts it's own pulse width. This has traditionally been the domain of the Power Commander, but now Motty Electronics are challenging this, with their AFR Tuner

    AFR Tuner
    The AFR Tuner (AT) is a closed loop controller. Initially, it uses the OEM ECU injector map, but it is also given a target AFR map, downloaded from a PC. It reads the current throttle position, rpm & AFR (from a wideband Oxygen sensor), and compares the actual AFR with the target AFR. It then builds & adjusts it's own fuel map to reduce the AFR error.
    Power Commander III USB
    The Power Commander, is available now in 2 variants, PC III & PC V.
    The III is open loop. Give it an injector timing map, and it will use that to control the injector times, dependant on throttle position & rpm.
    The V is a recent variant. It works in a similar manner to the AT, by building it's own fuel map from the target and actual AFR values.

How do you modify the map ?

  1. The traditional way, is to hire some dyno time, and measure the power characteristics of the engine.
    1. Do a dyno power run
    2. Make an educated guess as to the changes required in the fuel map, in order to arrive at the ideal power characteristic & desired AFR.
    3. Upload the newly modified map to the ECU, or fuel controller
    4. Repeat A B & C until the AFR error is acceptable

  2. The long winded, but far cheaper and more "real world" method of determining the new map, is to record data under repeatable conditions.
    1. Go for a ride & record the throttle position, rpm and AFR under known conditions - terain, temperature, aggression etc.
    2. Analyse the data in much the same way as would be done when using a dyno. An educated guess is made for each fuel map cell, in an attempt to move the AFR to the desired value (~13:1 for power, 15:1 or higher, for economy).
    3. Upload the newly modified map to the ECU, or fuel controller
    4. Repeat A B & C until the AFR error is acceptable
    The data is recorded with the help of TuneBoy or other data recorder, such as an Innovate LM-2 or LM-1 (obsolete) + LMA-3

  3. Then there is the automated method. A closed loop controller measures the AFR for each cell in the map, as it encounters it. It then makes an adjustment and builds it's own map. At the end of the ride, you choose whether to store the new map permantly, or discard it. This requires an AT or PCV.
    The beauty of this automated method, is that the map is adjusted constantly, as changes occur in altitude, air flow (filter clogging), exhaust back pressure (changed or failing can) or even fuel pressure.
The last method covers all the bases, and is the system I installed. It resulted in a dramatic improvement in fuel economy, from around 220 km from a tank, to over 300.
As a bonus, the AT provides an extra map. One I use when I'm looking for economy on transport sections. The other, the "go faster" map, can be switched in when the road gets "squirrely", providing power immediately from 4000 rpm, to the limiter.

How to Install an AFR Tuner

Two ways. Either with minimal loom modification, or, not.
The former is the way #922 is wired. It requires the creation of cable stubs, to make connections using the standard connectors. Some of these are difficult to acquire.
The latter requires the unwrapping of the main loom from stern to just behind the engine, and splicing into the relevant wire, using soldered joints. With this method, Items 5 to 13, in the Parts List below, can be deleted.

Wiring Diagrams
Tornado #922 AFR Tuner Wiring Tornado AFR Tuner Wiring
(click an image to download the wiring diagram pdf)

The following describes the minimal loom modification method
1. Connecting Main pin 20 to P1E4 MAY result in a cleaner TPS signal, but I haven't tried it.
2. Only 4 wires are spliced into the loom. All other connections are made by adding cable stubs.
3. The wire colours chosen, are not necessarily those found in the loom supplied by Motty.

Parts List

Item Qty Description Manufacturer Part Number Source Use
1 1 AFR Tuner, cables and mounting strips Motty AT2.2 Motty Electronics modifys the ECU injection times dependant on throttle position, rpm, current AFR and your AFR map
2 1 wideband lambda sensor Bosch 0 258 007 200 generally available, but try Tech Edge, Motty or Innovate Motorsports measures the amount of oxygen in the exhaust
3 1 stainless steel collar M18x1.5, 25mm OD, 16mm long shaped to but to a 50mm exhaust pipe Innovate Motor Sports 3736 your local machine shop, Motty or Innovate Motorsports weld this to your exhaust to mount the lambda sensor. See below for the position.
4 1 Handlebar switch right hand kill on-off & start Hi Level 694605 Motorcycle Products replaces existing switch block to enable map switching (re-wiring required)
5 4 2 pin female connector & boot Bosch 1 287 013 003-000 generally available, but in Oz: Ashdown-Ingram to connect to Engine Temp Sensor & injectors
6 4 2 pin male connector & boot Bosch 1 287 013 002-000 generally available, but in Oz: Ashdown-Ingram to connect to the OEM loom: Engine Temp Sensor connector & injector connectors
7 1 3 pin female connector & boot Bosch 1 237 000 003-000 rare, but in Oz: Ashdown-Ingram to connect to the Throttle Position Sensor
8 1 3 pin male connector Tyco/AMP Housing: 1-0144546-0, (3) Male pins: 0-0142755-1 extremely rare, unless you want 1,000. I managed to procure samples from Boersig GmbH, in Neckarsulm, Germany. Thomas is an absolute legend. Possibly also available from onlinecomponents.com to connect to the OEM loom: Throttle Position Sensor connector
9 1 3 pin female connector housing Tyco/AMP 282087-1 Farnell 150-423 connects to speed sensor cable to tap off speed & +12V supply
10 3 20-16AWG (0.64-1.3 mm2) crimp socket Tyco/AMP 183025-1 Farnell 151-075 to suit above
11 1 3 pin male connector housing Tyco/AMP 282087-1 Farnell 150-423 connects to speed sensor cable to tap off speed & +12V supply
12 3 20-15AWG (0.64-1.5 mm2) crimp pin Tyco/AMP 183024-1 Farnell 151-040 to suit above
13 6 Green wire seals Tyco/AMP 281934-4 Farnell 150-915 seals the wires in the 2 housings above
14 1 extraction tool Molex 11-03-0044 Digi-Key WM9918-ND tool to remove pins from the AT Main plug
15 20 24-18AWG (0.2-0.78 mm2) Female Crimp Contact Molex 39-00-0207 DigiKey WM3116CT-ND to suit AT Main Plug
16 2 m each 0.75 mm2 Black (2x), Brown, Red, Orange, Yellow, White pvc insulated wire . . . .
17 2 m each 0.5 mm2 Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White, Pink pvc insulated wire . . . .
18 1 m 4 mm pvc tubing ProPower PVC-4-0-CL Farnell 130-2785 to cover the injector & temp sensor wires of the AT loom
19 1 m 6 mm pvc tubing ProPower PVC-6-0-CL Farnell 130-2785 to cover the TPS wires to the AT loom
20 1 roll cloth backed 20 mm wide automotive looming tape United Partners P/L N1010 K&R Car Parts, Seven Hills, NSW for wrapping the AT loom

Fitting the Lambda Sensor

The Lambda probe will fit just in front of the exhaust pipe mount, but behind the gearbox, angled to miss the clutch cover. I shaped the collar base to fit the curvature of the pipe, marked the position on the pipe, then drilled a hole in the pipe, just large enough to allow the probe to fit through. A bolt then held the collar in position for welding.

Lambda probe site
Lambda probe collar
Lambda probe collar angle
Lambda probe site
Lambda probe collar
Lambda probe collar angle

The collar is just a little close too the exhaust mount. The TIG torch very nearly didn't get in close enough. 10mm further upstream would have made the welding task much easier.

Fitting the AFR Tuner

Firstly, remove the ducktail, right lower & upper panels, the tank, and right airways. You'll then have access to everything you need to get to.


AT Mounting Position
AT Mountin Tabs
Raise Fusebox
The AFR Tuner (AT) mounts above the right fan pod
The AT is held in place with 3M "Dual Lock"
The fusebox must be raised or shifted left.

The AT will fit in the duck tail, between the fans as shown above, if the fusebox is raised, moved left, or allowed to float freely. Initially, just lift it off it's clip. The top of the AT metal case should be protected from connecting to the frame by super gluing a piece of PETE (from a 2 litre juice bottle) to it.
Motty supply 4 pieces of Dual Lock in the AT kit. Clean off the fan & AT housings with isopropyl alcohol, and when dry, stick 2 to the end of the AT (as shown), then slip it into position. Rotate the part sticking to the fan, so that it follows the curvature of the fan housing. Next, remove the AT & stick the remaining 2 pieces to it's underside, in a position that will line up with the right housing.
I raised the fusebox by rotating it's clip through 180o. An extra notch is required though, and the pillion seat will touch it.

clip hole slotted
clip in profile
clip mount
File a vertical slot so that the clip can be rotated 180o
The fusebox clip in profile
End view of the fusebox clip

Take care when removing the clip. The tips are sprung loaded, and must be squeezed together to allow the clip to be withdrawn.

clip in place
fusebox wiring unwrapped
taped for wrapping
The clip in place
Wiring to the fusebox is unwrapped to improve placement
Diag. plug moved to fit AT coms & aux. power outlet

Now that the clip is remounted, unwrap the looming tape from the wiring to the fan plugs & fusebox, to allow re-looming in a more appropriate position - later.
Mount the AT, and move the diagnostics plug to the position shown. Also move the diode plug & assembly back and across, to make room for the AT coms plug. I have an accessories power supply jack that I fitted a while back (to charge my phone & gps receiver), which had to be re-positioned as well.

RHS Looms
Injector Plug Plan
Injector Plug Face
Cables L-R: AT coms, Lambda, Fusebox, AT Main
OEM Injector Plug
Injector Plug Face

It's now time to remove the battery and the ECU.

Looms At Fuel Rail
New TPS plug
AT Loom Left side
OEM & AT Looms at the fuel rail
New TPS plug fitted
AT Loom Left side track
??
??
Main Gnds & rpm
Loom behind the engine
loom in the ctr - lambda plug unconnected
Main Gnds & rpm wires pre-soldering
Main Gnds & rpm
Main grounds & rpm signal
P2 detail
Main grounds & rpm wires ready
Main grounds & rpm wires connect to P2
More P2 detail
ECU P2
ECU P2
ECU P2
Forming up P2 loom
P2 loom again - pre-wrap
P2 loom formed & wrapped
ECU P1 & P2
Looms to ECU
Loom Below ECU
ECU P1 & P2
Looms to ECU
Loom Below ECU
??
??
??
completed loom at right rear
completed loom at AT
tail re-wrapped