ACCELERATOR MODULE for BMW

Hier is bietjie info.

http://www.wilddog.za.net/forum/index.php?topic=58420.0

Kyk ook na een.

Several of these devices are on the market. Some clever guy opened one and found only one resistor inside.It is now common knowledge that you can buy an adjustable resistor for under R10.00 from JEBO Electronics next to Brights in Bellville. Adjust with an ohm meter to 500 ohms.If you remove your front seat on the 1200 GS you will see on the left side of the bike where the seat bracket  secures the front seat there are two wires isolated. Remove the isolation and you find a blue, brown and grey wire. Cut the brown and grey wire and solder the resistor in line.It works very nicely. I can accelerate from 1000 RPM smoothly in second and third gear.The resistor tells the fuel management system it is 30 degrees colder than it actually is  and the engine therefore receives more fuel. Another system regulates the fuel system thereafter.

Why not just buy a 500 ohm resistor?  Unless you want to be able to adjust the resistance to fine-tune the effect.  I would think a 1k preset would be just the thing for this.

Which are the wires on the 1150GS?  Or does the 1150 not really need this since it does not run too lean?

You can probably just use a 500 ohm resistor. I used the adjustable one as I was told you can tweak it a bit for best results but that I have not done yet. If you surf the web under the same name you will get a lot more info and it tells you on which bikes it works

Hi Mike! Jy moet mos al slaap die tyd van die nag jong, of hoe?

Hier's 'n plan: ek bring my bike na jou workshop toe, dan sit ek met 'n koppie koffie en kyk hoe soldeer jy hierdie stukkie "magic" in my fiets in! As ek dit moet doen sal ek net die Adventure aan die brand steek...

Nogaal geinteresseerd in die ding, sal met jou kom gesels. Maar ek gaan nou eers vakansie hou, sien jou diep in Julie.

Since the tuning operation on the 1150GS is very manual, could I not just get Andrew King to make it a bit richer?

@Frans:  it might be a good idea for warranty purposes etc just to buy the Bosch plugs and make your booster device unpluggable.  It seems the Bosch plugs are fairly standard and not too expensive, and now you can solder the resistor away from the bike and just plug it in line when you want it.

My 5 cents

The operation and effect of the 'accelerator module' is very interesting indeed.  Basically the 'value' of the intake air is reduced to bluff the ECU (Electronic Control Unit) into increasing the fuel (making it richer). (colder air is denser and thus more Oxygen, more fuel is required for optimum burn.  That is basically that.

BUT

all the intricacies in the ECU, Mapping and the Lambda sensor give a totally different end result than simple tuning.  The name is ACCELERATOR module, not fuel saver/power enhancer/etc/etc and therein lies the 'trick'

As the engine revs go up the ECU will select the appropriate 'cell' in the MAP (Fuel tables) to inject the optimum amount of fuel.  These values in the MAP is also adjusted via the the feedback from the Lambda sensor (The thingi sticking out of the exhaust normally less the 500mm from the engine).  This combination is in essence why modern fuel injection engines is 'auto tuning' (up to a point)

Most users finds that the engine is quicker to start, better idling, better pull away and better fuel economy.

Having a richer mixture during Idle and pullaway is to be expected, the better fuel consumption is a bit more complex and could be related to riding style.

The beauty of the system is that it should only enrich the engine during idle and throttle changes as the Lambda will sense the 'overdose' of CO2 during constant throttle and 'adjust' the volume of fuel to meet the set CO2 values at that speed and extend the planets life (saving is something different). (the Lambda normally go into 'the background' during idle and acceleration)

The increase in fuel economy could be the result of better aceleration (quicker at speed for the Lambda to 'kick in') because theoretically the engine use MORE fuel during idle and aceleration ???  If I can remember correctly during the fuel crisis (late 60's) aircraft climbed steeper from takeoff (using more fuel) but level flight were longer (less fuel) to achive overall fuel savings.

Adie

P.S. In the old days with carberettors the mixture were enriched with a little squert of fuel when the pedal was pressed, it now happens in the blink of an eye through a silicone flake with optimum precision. 

Jissie Adie, nou praat jy darem hi-tec googledi-gook! 

We have some knowledgable folk in our ranks.

Most of these devices claim to compensate for changes in the ambient temperature, in other words, they don't just use a fixed value resistor, but rather a type of resistor whose resistance varies with temperature exhibiting a 'negative temperature coefficient', meaning as it gets colder its resistance goes higher. (see http://www.ebbo.org/resistor_tuning.php)

Whether that would be necessary here in the Cape where the temperature seldom gets close to 0is debatable. I reckon an adjustable 500ohm would be fine... can trim for winter vs summer if really necessary.

Another thing they claim is that since you are adding resistance in series, the total resistance will never be less than your stock setup, so it can never run leaner than stock (i.e. without the added resistance installed).

does it work and will it damage the engin.

Is it worthwhile spending the money for it +-R800.

Most of you are speaking about the 1150 and 1200's. What about the 650's.

Shane resetted my bike's computer on the last service and I must say it runs like a dream again. I think it got confused with the new K&N filter. Now do I scratch where it do not itch.

Don't spend R800 on components you can get for under R50.  Essentially, all you need is a 500ohm preset resistor (R20 max), and if you want to keep it looking neat and be removable rather than soldering stuff onto the bike, a male and female Bosch plug of the type that is used on your airbox air temperature sensor.

What do the Bosch plugs look like and where can one get them? Pictures would be appreciated (for the ungifted..)

Bosch Plugs: Top right of the picture is a male and a female bosch plug

These are the same as the ones that plug the wires into the air-temperature sensor in your airbox.  Where you get them I don't know.  There must be a place that supplies them between here and Durbanville!

I got hold of a 470 ohm resistor and fitted it this morning as per Mike's instructions.  There is a definite improvement when riding in traffic at low revs in the higher gears - the bike pulls better.

I am going to Elim tomorrow so I will see if there is an improvement on the open road.

After the trip to Elim with some open road and some gravel I can say that there is an improvement.  The bike is more tractable.  

Fuel consumption is much the same. I filled up at the One Stop and then again at Gansbaai.  I had travelled 240km and the bike took 13 litres.  That is 18km/l or 5.4l/100km.  I was carrying a pillion and the wind was blowing strongly, for part of the morning, which increases fuel consumption.

I would say that this is a worthwhile modification.

Where are the engineering / electrical diagrams, installation guide, user manual and pictures?

Don't you have the time to do these posts properly now

Well said Tony.  I have all the time in the world now.  But I may have difficulty with the diagrams, guides and manuals.  You must remember that I was a platpoot.  When I joined in 1972 they asked me "Boetie kan jy 'n skollie donner".  When I answered in the affimative I was in.  All this writing business came later.

However, digital photography to the rescue.  I made the resistor a temporary fixture in case it didn't work. When I solder it in place I will take pictures and post them.

I recently rode up to Pretoria.  The resistor was fitted for the trip there. I removed it for the trip back to see if there would be a difference..

Here are the results:

Cape Town to Pretoria - fuel used 101.65 liters - distance travelled 1464km - 6.94 l/100km

Pretoria to Cape Town - fuel used 90.21 liters - distance travelled - 1522km - 5.93 l/100km

I made a short detour over the Gariep dam wall which accounts for the extra distance on the way down.

That is why I mentioned in my tech overview that I do not think it will neccecarly (allways) affect fuel consumption. In town maybe, open road unlikely.

I drove a chevvy spark between Sabie and cape town many times (3 cyl 800cc - was I mad, maybe!!)  the down trip allways used less fuel.  (it is not only downhill due to the elevation it is also down on the earth ball (globe).  In my mind a ship should use less fuel from Europe to Cape Town as it is 'down' )

A

What was your average speed for the two legs? Did you ride with panniers/pillion?

PS still no pics / documentation of said modification

Tony, I had the Krauser panniers and a tail pack and no pillion.  Most of the time I cruised at 120 or 130 but on occasions I would do 160 or so for 10 or 20 k's.  Coming back the wind was much stronger.

I will take the pics this week and post them.

I've noticed that the panniers have a marked effect on fuel consumption.