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Booster Plug
- Thread starter 1998f150
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- af-xied booster plug
Visian
look out!!!
I put one on my 2000 R1150GS, mainly because a friend sold it to me cheap.
Don't buy this for added power, but it has a noticeable impact on surging and low-speed fueling.
Together with Rob Lentini's Zero=Zero throttle body synch procedure my bike runs quite smoothly.
Ian
Don't buy this for added power, but it has a noticeable impact on surging and low-speed fueling.
Together with Rob Lentini's Zero=Zero throttle body synch procedure my bike runs quite smoothly.
Ian
36654
New member
You have been around here a long time!.....
roger 04 rt
New member
The Motronic quickly learns about and then compensates for the error introduced by the BoosterPlug.
Lentini's z=z procedure is wrong since the Bosch TPS is specified to be 250 mV at zero degrees.
If you're interested I can provide links that explain both issues.
Lentini's z=z procedure is wrong since the Bosch TPS is specified to be 250 mV at zero degrees.
If you're interested I can provide links that explain both issues.
roger 04 rt
New member
Here is some research on why you should not adjust the throttle stops unless you need to due to tampering or TB rebuilding, but if you do have to why the procedure should be zero=250: http://forums.bmwmoa.org/showthread...yond-Zero-Zero&p=952354&viewfull=1#post952354.
Here is a detailed explanation of how the Motronic uses a process called Mixture Adaptatiin to negate the effect of shifting the air temperature sensor (or fuel pressure or ethanol content): http://advrider.com/index.php?threa...-af-xied-for-bmw.749080/page-40#post-23675190.
And here is the research that shows why/how Oxygen Sensor shifting (Innovate Motorsports LC-2 or Nightrider/Beemerboneyard AF-XIED) effectively richens the mixture: http://forums.bmwmoa.org/showthread.php?56990-2004-R1150RT-Wideband-O2-Sensors.
The above are the results of detailed measurements of BMW motorcycles over the last several years.
Here is a detailed explanation of how the Motronic uses a process called Mixture Adaptatiin to negate the effect of shifting the air temperature sensor (or fuel pressure or ethanol content): http://advrider.com/index.php?threa...-af-xied-for-bmw.749080/page-40#post-23675190.
And here is the research that shows why/how Oxygen Sensor shifting (Innovate Motorsports LC-2 or Nightrider/Beemerboneyard AF-XIED) effectively richens the mixture: http://forums.bmwmoa.org/showthread.php?56990-2004-R1150RT-Wideband-O2-Sensors.
The above are the results of detailed measurements of BMW motorcycles over the last several years.
globalrider
Alps Adventurer
roger 04 rt
New member
You should use that if you feel you need to do anything. I outlined the final cable tensioning sequence for the R1150 but it can be different on the R1100.
I have a 2004 R1150RT and after carefully going through the valve adjustment procedure with 4 feeler guages and rechecking everything, I changed the spark plugs and performed a throttle body synch. Still had some minor surging. I installed a Booster Plug and my bike is now 95%+ surge free. Yes the Motronic relearns but in its simple form, the Booster Plug makes the Motronic think the air is a bit cooler than it is (read denser) so it adds bit of time to each injector pulse - enough to reduce the lean surge to tolerable levels. It was always worst at light throttle and light loads and that's where the booster plugged helps. $140 well spent IMHO.
I have also learned to hold it in lower gears longer, the engine likes to rev, not lug. It all helps.
I have also learned to hold it in lower gears longer, the engine likes to rev, not lug. It all helps.
roger 04 rt
New member
The booster plug does as you say, at first. It accurately offsets the air temperature sensor by 20 degrees centigrade. That leads the Motronic to add about 6% more fuel. So far, so good.
But then, as the Motronic compares the actual fuel used in Closed Loop, with its initial calculation of fuel based on the 20C offset, it "learns" that it takes 6% less fuel to hit the set point of the O2 sensor (14.7:1 unless you run an LC1/2 or AF-XIED). After learning that it takes 6% less fuel, over the course of a few tanks of fuel, the Long Term Multiplicative Fuel Trim gets reduced by 6% (starts at 1.00 and reduces to 0.94).
That long term fuel trim is applied to the entire map and the measured AFR after installing the BoosterPlug is the same as before installing it, once you've run a few tanks of fuel.
For about $20-$70 more than a BoosterPlug you can install a lambda-shifter like the LC-2 or AF-XIED. If you do the Oilheads pull well in high gears (4th, 5th and 6th), right down to 2000 RPM.
But then, as the Motronic compares the actual fuel used in Closed Loop, with its initial calculation of fuel based on the 20C offset, it "learns" that it takes 6% less fuel to hit the set point of the O2 sensor (14.7:1 unless you run an LC1/2 or AF-XIED). After learning that it takes 6% less fuel, over the course of a few tanks of fuel, the Long Term Multiplicative Fuel Trim gets reduced by 6% (starts at 1.00 and reduces to 0.94).
That long term fuel trim is applied to the entire map and the measured AFR after installing the BoosterPlug is the same as before installing it, once you've run a few tanks of fuel.
For about $20-$70 more than a BoosterPlug you can install a lambda-shifter like the LC-2 or AF-XIED. If you do the Oilheads pull well in high gears (4th, 5th and 6th), right down to 2000 RPM.
jammess
Jammess
Ian, What Roger says is without doubt true. I went the booster plug (homemade) route and took a week long trip of several thousand miles and found I had to do a TPS reset every couple of tankfuls to compensate for Motronic relearn. I finally through in the towel and installed an LC-1 with wideband O2 sensor and have never looked back. What Roger says about increased low end torque is spot on as well. The booster plug is not the proper way to address lean burning with these machines. If you like your bike's performance with the booster plug that's great but that's just not the best way to address the lean burn surging problem long term.
Visian
look out!!!
Understood... I know very little about these things, I just know that I reset my TPS about 15 years ago and haven't touched it since. The only reason I put on the booster plug is that I only had to pay $25.
I'm going to research those O2 sensors though, sounds interesting.
jammess
Jammess
Hi Ian, I liked the performance on the 1150 with the Innovate Motor Sports LC-1 so much I installed the new LC-2 on my '93 R1100RSL even though it had no surge issues after disconnecting the narrow band O2 sensor. I did it because of the effect a richer mixture has on performance especially in torque at low RPM improvement which is just phenomenal. Totally transforms the motorcycle. I am running at an air fuel ratio of 12.9:1 which is considered by some hot rod tuners to be the AFR which is good for lean best power output. I concur!
roger 04 rt
New member
Jim. How do your plugs look after a year at 12.9?
jammess
Jammess
Recently replaced plugs as part of general maintenance. Primaries looked clean with a very slight tan color. Secondaries looked fairly dark but dry. I am using a higher heat range on secondaries. On my last long fall (late summer) ride using regular ethanol most of the time I actually averaged 51 mpg and had no discernible pinging or other issues. Most of that ride was in WA State so very hard to find non-ethanol. On a ride like that I often use regular grade because I think it might be fresher than premium grade ethanol.
vachenleug
Wild Boar
Booster Plug mod on 1150RT
I installed the booster plug on my 1150RT and after a few hundred miles I was not satisfied with the performance.
I then removed it and installed a John Gemi Chip in the mototronic unit. Now I am satisfied. No surging. Gas mileage has improved too.
Under $100 plus shipping. Check Ebay for this item.
I installed the booster plug on my 1150RT and after a few hundred miles I was not satisfied with the performance.
I then removed it and installed a John Gemi Chip in the mototronic unit. Now I am satisfied. No surging. Gas mileage has improved too.
Under $100 plus shipping. Check Ebay for this item.
cam_on_van_isle
Member
I have an 1100, so it may not apply, but the best bang for my buck was injectors from tills.de.
Instant, noticeable improvement.
Instant, noticeable improvement.
