Booster plug review

It's a big twin. None that I've had were really comfortable at less than 2000 revs; running a lower gear will be kinder to the engine as well as smoother. Still, glad you're happy with the booster plug, I got a similar improvement with an O2 sensor eliminator on my Tiger 955i.

Glad it works for you. I used a booster plug on a K1600GT and then on my R1200GS TC and honestly couldn't feel much difference.
My TC didn't hesitate at low revs but was very harsh and viby which was why I tried the booster plug. I think that some GS's have better fueling than others which may mean some hesitate more than others.
You should not see any difference in fuel consumption with the booster plug. It only enriches the mixture when you are twisting the throttle. On a light throttle opening, the mixture goes back to normal so the overall consumption is not much different.
Some believe that the ECU eventually compensates for the booster. No idea if it's true.
I've fitted a Power Commander 5 to my TC and the difference is day and night. Mine will pull from below 2k but I agree with greenman, it's not good for the engine and transmission.
I like to keep mine spinning above 3k and use the gears a bit. Much smoother and more responsive.

Booster plug made mine feel soggy and use a lot more fuel. Not impressed.

I now have a power commander which pretty much echoes the previous post. It "can" pull below 2000rpm in higher gears but Im sure its hammering the crank and rods so I avoid slogging the engine. The low revs ability does come in handy when caught in the wrong gear. The engine is less likely to stall suddenly and throw me off but as said its best to avoid habitually slogging the poor thing.

i fitted one on my 04 GS and had definate improvement on idle the bike no longer feels like it wants to stall. i haven't noticed any great diference on fuel consumption but rides a lot smoother around town.. Not had a chance to test on a really hot day so will wait and see if any thing changes. if we ever get a really hot day....Not sure if real value for money as yet..

I think the Booster Plug is more beneficial on the pre T.C. bikes...

I've just fitted one on my 08 GS (this morning). It didn't seem to make any difference at all low down and over 4k performance was down!!! I took it off after half an hour and rode it back without it just to be sure.
I've now posted it back and will just leave it as it is.... very slightly woolly below 3.5k and brilliant over 4 with the akrapovic headers on.

The plug made such a difference in Mylady's F800GS -08 so I'm seriously considering installing one in my R1200GS -06 too.
I also believe that the plug is more useful in older models. Newer ones ought to be more refined, logically.

I fitted one to my F650gs single spark and it was like night and day! The bottom end was improved to
the point I could trickle along in first gear with the clutch out and the revs just cracked. Before fitting the plug the
bike would have stalled with out question. Pulling away felt much more confident, and that gave me more of a good
feeling in traffic or at junctions.
I have just ordered another for my R1200gs, il post as soon as its fitted and had a few miles of use.

I think the logic behind these things is good.
Manufacturers have, for various reasons, tended to be towards the "too lean" end of the combustion envelope.
These plugs "fool" the engine management into thinking is a tad cooler ( OAT) than it really is.
The outcome is; the mixture is a little richer. the engine runs cooler, burn is different and the rider is happier with a smoother runnning bike.

I have the "accelerator module" from Sol2be fitted...... it definitely cleaned up slow speed manoeuvrability, pulling away and coming to a stop.

Sent using a Jedi mind trick!

My booster plug did improve low throttle settings but fuelling overall was worse so it didn't stay long on my bike.

The PC5 made 10x the difference. It was so good the bike even seemed to handle better. Yeah right!!! But instant power (or not) exactly when needed rather than the old hesitancy makes for smoother riding. Top end is insane, bottom end is smooth and no flat spots. Fuel consumption has taken a hit so (IMO) the more elegant remap is a better option and costs about the same.

The booster plug is a resistor that connects to the AIT (air inlet temperature) sensor.
This tells the BMSK ecu that it is colder than it is, so it richens the fuel mixture.
In closed loop the lambda sensor sees that the mixture is rich and instantly corrects it.
Use a wideband sensor and data logger and you will be amazed at how fast and how good this BMW setup is at correcting it.
In open loop the booster plug will make a difference for a while but the BMSK will adapt it out via long term fuel trims.
If you reset the adaptations every week it will continue to show a difference in open loop.
The Power Commander V runs on its own map but by disconnecting the lambda sensors all the adaptation benefits of the BMSK are lost.
The BMW AF-XIED is perfect in closed loop and the open loop adapts from this. It is easy to fit and takes no setting up and retains all the wonders of the BMW ECU.
Having tried all these + other options, Fuel pressure increase etc, etc I am still unable to find a better fueling option than the AF-XIED.

Are you still running the AF XIED? I'm looking at that option hence my other thread about logging. Wanted to check lambda voltage, then fit de catted headers and measure again, fit an XIED and measure again. Think standard it can run up to over 1 which I believe is lean. Wanted to compare that to the decat headers when fitted then with the AIED hope to get it to average .94 which I think is 13:8to1.

Think it is also outside the scope of the BMW module's adaptations isnt it?

Yes I have had the AF-XIED`s on for over 20k miles and just swapped them onto my 2012 twin cam
The lambda output voltages will be the same with the decatted headers as the ecu will compensate for it. and adapt to them.
With the AF-XIED`s fitted you will still get the same readings from the GS911 on narrow band lambda`s, the signal from the lambda sensors is digitally modified so that the ECU runs the fueling richer.
To simplify it, The ecu tries to keep the mixture at 14.7 to 1 when in fact as the signal is modified so the bike is actually running at 13.8 to 1.
The only way to measure this is to run the GS911 recording the narrow band data and weld another set of fittings in the exhausts to take a pair of wideband lambda sensors hooked up to an innovate LM2 to record the true air fuel ratio.

Photo of extra lambda fittings.


Graph recorded of air fuel ratio with wideband sensors and Innovate LM2.
http://i1031.photobucket.com/albums/y371/Mistacat1/xeid setting 7 01 01 16_zps0rp3g0oc.png

Here is the graph of the data showing air fuel ratio recorded with wideband sensors and Innovate LM2. ( at the same time as this the GS911 was showing 14.7 to 1) which shows how well the setup works.

http://i1031.photobucket.com/albums/y371/Mistacat1/xeid setting 7 01 01 16_zps0rp3g0oc.png

It works better than loading this graph. !!?

http://i1031.photobucket.com/albums/y371/Mistacat1/xeid setting 7 01 01 16_zps0rp3g0oc.png

Thanks for that. A lot of useful info there. In effect i don't need to log the data now as you point out the bike will adapt and modify to changes bringing it back to 1 or near as damn it. I guess the xied gets lambda signal and reduces it before sending it to the ecu so ecu chucks more fuel in.

Having a Log from when the bike is running ok is a handy reference for the future.
Best to Log all 30 ish perameters.
The BMW ecu and system is brilliant and will adapt to many different changes, such as air filter/condition, exhaust system, Fuel ethanol content & quality, barometric pressure, air temperature, engine temperature, fuel pressure, injector condition (worn or gummed up) etc.etc.
The AF-XIED just tricks the BMW ecu into doing its brilliant job but at the air fuel ratio that we set it at.

Hi Mistacat.
For us simple folk.
I have a PCV and have just fitted an Autotune module to my TC. De catted headers and no flapper.
I like the change that the PCV has made but am intrigued by the AF-XIED and have been trying to get my head around it.
I'm not keen on the extra wiring and not terribly waterproof connectors that come with the PCV. Always have been uncomfortable disconnecting the O2 sensors. Kept them in just in case the PCV went faulty on the road, I could reconnect them.
Bottom line.
Do you believe that the AF-XIED will give me the same benefits as I have now?
Did you use a PCV before you fitted the AF-XIED?
Was a bit concerned when replacing the O2 sensor for the Autotune as the original sensor was quite sooty, indicating that it could be running a bit rich. According to the PCV software the target AFR is 13.2 which is starting to sound a bit on the high side.
I'm almost persuaded on the AF-XIED. Just need a bit of reassurance before parting with that much cash.

I have used PC 3`s on Jap bikes with basic open loop systems with great success.
I had a PC V and the autotune on my 2009 GS which was a good improvement over stock but it meant compromising a very sophisticated fuel management system and trying to run it as an inferior open loop system without adaptation ability.
I was forever playing with the PC V trying to get it just right.
I first came across the concept of Lambda offset devices many years ago, I used an Innovate LC1 driven by a Bosh wide band sensor. This gadget had the option to program one of its outputs to simulate a narrow band sensor to and you could program it to run whatever air fuel ratio you chose.
These were great in a car but a bit bulky and messy (wiring) on a bike.
A few years ago in America a chap, Roger RT04 started experimenting with an innovate LC1 on an oilhead RT ( one lambda sensor) he posted the results of this over a couple of years which I followed with interest A. (being a fuel injection anorak) & B. having played with the LC1 and still have one on the shelf.
The results looked promising but 2 x LC1`s would be needed on the hexhead. ( 2 lamda sensors) and they would take up a lot of room.
I understand that Roger discussed his results with Nightrider who had for some time been marketing lambda offset devices for Harley Davidsons etc.
The problem with the BMW was that it was not as simple as Harley`s and needed a digital processor to control the lambda offset.
The long and short of it is they started manufacture and Beemer boneyard dropped Power Commander and became distributors of the AF-XIED.
I ordered a set from them in Florida fitted 2 them years ago over 20k miles and have recorded loads of data and settled for setting 7 = 13.7 to 1 .
If I go touring I sometimes set them on 6 = 14.1 to 1 air fuel ratio with the seat off this takes less than 10 seconds to adjust with a little screwdriver.
Are they Perfect, NO !!! I would ideally like to be able to switch on, in open loop a pc3 or techlusion that I could further tweak the open loop fueling but this would involve disabling the adaptation ability of the BMW ecu. which would be going backwards. after all the newer the bike the longer they seem to operate in closed loop. ( I think I will put my anorak away and put my helmet onand just ride the bike)
I have just upgraded to a low mileage 2012 twin cam so the XIED`s are now on that.
A few of my mates now have them on their GS`s and seem happy.
Photo of one of the AF-XIED`s mounted on the airbox. They are plug and play disconnect the lambda sensor and plug it in + a ground/earth wire to connect.
http://i1031.photobucket.com/albums/y371/Mistacat1/2015-04-24 18.34.02_zpsphgq9bos.jpg