Accelerator Module

[VFRman]

New solution

All the module does is fool the ECU in thinking the air temperature is 20 degrees cooler than it actually is, so the bike adds about 6% extra fuel. That can't be lost over time and there's nothing the GS can do that would adapt that setting to anything else - the incoming air temp is not one of the adaptive values ( I can reset these values from the GS911 and air temp isn't one of them). I have a module and several times hooked up a GS911 to be sure thats what it was doing which it .

This is we're the debate is, does it or doesn't it adapt out the air temp fooler 20deg? From what I've read so far the GS911 doesn't have access to the fuel injection ecu, if it could we would be able to play with the fuel map?

So bottom line, if brain hurts from reading long thread, buy the booster plug fit the unit and see for yourself...I did and i didn't notice a difference but it didn't cost much to find out so I'm happy.

My brain hurts, I did read the long thread, so you don't have to, and I bought and fitted this:

http://http://sales.nightrider.com/BMW_upgrades.html

It works for me, so far only tried setting 7, 6 and 8 to try before deciding which to go with. This kit changes the output of the two O2 sensors so fools the ecu into controlling around a richer air fuel ratio. It works

 

[Delboy777]

This is we're the debate is, does it or doesn't it adapt out the air temp fooler 20deg? From what I've read so far the GS911 doesn't have access to the fuel injection ecu, if it could we would be able to play with the fuel map?

So bottom line, if brain hurts from reading long thread, buy the booster plug fit the unit and see for yourself...I did and i didn't notice a difference but it didn't cost much to find out so I'm happy.

My brain hurts, I did read the long thread, so you don't have to, and I bought and fitted this:

http://http://sales.nightrider.com/BMW_upgrades.html

It works for me, so far only tried setting 7, 6 and 8 to try before deciding which to go with. This kit changes the output of the two O2 sensors so fools the ecu into controlling around a richer air fuel ratio. It works

ffs at that price you'd be as well getting a remap. Module only costs 50 euro for the extended version.

 

[VFRman]

Only if you can afford to...

Yes, not cheap at about 3% of the price of a fully loaded 90th GSA, or go to hilltop and let them do a re-map for a similar price, the choice is....

 

[Bendy toy]

A remap (or Power Commander) will optimise the fuelling over the whole rev range. Something, however clever, than works on just one aspect of the engine management wont fix issues with the original fuelling map.

 

[Delboy777]

Yes, not cheap at about 3% of the price of a fully loaded 90th GSA, or go to hilltop and let them do a re-map for a similar price, the choice is....

I agree, but if the module does what it says it does and there are plenty on here that say it does, then that is all that matters is it not ? Most sensible peeps will realize that it only does one thing, as Bendy says, so if it smooths out the fueling and stops the snatchy throttle syndrome, then its worked.

 

[Mistacat]

I am also waiting for the delivery of a BMW-AF-XIED from Beamerboneyard.

Played with the PC 5 and autotune for 15k miles, monitoring it with GS911 and Innovate LC1. Results were good But!

Have followed this XEID development with interest.

PC 5 now removed and BMSK adaptations reset.

Logged with GS911 and LC1 for pre install figures. gonna be interesting to see if this XIED lives up to expectations.

 

[SteveM]

This is we're the debate is, does it or doesn't it adapt out the air temp fooler 20deg?

It does work. Not quite a -20 degree difference in temperature, but close.
You can feel a real difference when riding, it's much better, and better economy too.
2011GSA

 

[Mistacat]

Hi Steve.
Firstly I am no expert, just someone trying to learn how his bike works.
I think that....

The AIT ( air inlet temperature) shift devices ( accelerator module / booster plug) do have an effect.
As do changes to ...Fuel pressure.
Engine Temperature.
Throttle position sensor.
Barometric pressure. etc.

All these are inputs into the BMS-K ( bmw ecu) which controls the output namely IPW ( injector pulse width).

The aim of the BMS-K in closed loop is to obtain an AFR ( air fuel ratio ) of 14.7 to 1 = 1 lambda
or in fact (oscillate just above and below this figure to make the catalytic converter work) .

In closed loop as soon as the lambda or o2 sensor detects a shift from 14.7 AFR it is corrected.

Hence the AIT shift device cannot work in closed loop.

If you plug your GS911 in and log a ride up to 30 % throttle ( Closed loop) whith the engine warm, you will see the lambda correction factors,( not the lambda sensor voltages) ( multiply these figures by 14.7 to get AFR ). compare these figures with the IAT device before and after fitting.

The Open loop is adaptive and learns from the closed loop ( albeit slowly) Hence in open loop the AIT shift works but slowly gets learnt around. You need a wideband sensor coupled to a LC1 or similar to monitor this.
After a few hundred miles remove the AIT shift device and it will run rough (lean) if you then reset the BMS-K it will run ok, refit the AIT shift and it will run strong and start leaning all over again.

The power commander 5 does not use the lambda sensors and runs in open loop on the map you install in it.
The PC 5 alters the injector pulse width after the BMS-K so it does not know this is happening.
But it does not seem to co-exist with the BMS-K perfectly.

The BMW-AF-XIED ( claims to be able to) shift the lambda input signal to to make the BMS-K think that it is running a different AFR and richen`s the mixture. This is in closed loop and in time the open loop learns from this.
In Theory this should work in total harmony with the BMS-K, We will See.

The BMS-K is an incredibly clever computer just needs tricking into doing what I want, not what the emission controls say BMW must have.

 

[SteveM]

Hi Mistacat, sounds like you know far more about this subject than most (and certainly a lot more than me). I was simply highlighting the fact that the accelerator module does fool the computer into thinking its colder than it actually is, and that the subsequent fueling of the bike translates to a better riding experience.
I applaud your quest to understand exactly how your bike works. It means that people like yourself can authoritatively comment on people's woes on forums like this, rather than speculate.

 

[Mistacat]

Hi Steve,

As I let the clutch out at low rpm I get a nasty little swing to lean over AFR 16-1 before going rich.

I am assuming that this must be in open loop, so the accelerator module could help cover this and smooth out low speed throttle transitions.

It is also claimed the use of AIT shift devices speeds up the open loop learning of the BMW-AF- XIED.