Booster Plug Installation

[2xrboys]

I am trying to install a Booster Plug on a 20007 1200rt. Does anyone have pictures or descriptions of where the unit plugs in on the bike? I found a likely looking plug on top of the left throttle body but the plug doesn't want to seat all the way. I want to make sure I am hooking up to the correct wiring. Thanks for any input.

[dirtrider]

Afternoon 2xrboys

 

You have to remove the L/H plastic. The IAT (intake temp sensor) is on the top of the air box (at left rear of gas tank). Kind of in a pocket area under the left rear of the gas tank.

 

 

[Swag]

Okay, what is a booster plug?

[GRB60]

It's a device designed to fool the bike into thinking it's colder than it is in order to richen the mixture. It may or may not make the throttle response better or add power.

[NewBlue]

Okay, what is a booster plug?

 

The IAT, intake air temp sensor, is used as part of the fueling calculation. Cold, dense air would require a richer fuel mixture. Adding the booster plug lets the fuel system think the air is colder then it actually is thus giving you a richer mixture. Simply put it's a resistor. The IAT sensor is limited as far as the fuel system is concerned, about 6% in the scheme of things. The addition of the booster would be less noticable at cooler temps. What will happen though is when the system is in closed loop and the HO2S is used it will been seen as a rich mixture, eventually the adaptives will correct for this and cancell the effect.

It's been done for years, as long as an IAT or ECT has been used with EFI. Some down sides are hard hot soak starts, fouled plugs, carbon build-up, etc. Nothing new and IMO a waste of time.

[aggieengineer]

I've been using a Booster Plug for the last year on my 2008 RT. It's not just a simple resistor, but the website can explain that in detail. Fuel flow is only increased during acceleration - open loop operation. My observations are no change in starting or spark plug cleanliness, but the low rpm shudder before warmup is completely gone. That was the one thing that bugged me about the bike, so I'm quite satisfied with the Booster Plug. I look at it as just one small way to get the EPA out of my hobby.

[dirtrider]

Okay, what is a booster plug?

 

Morning Bswag

 

 

As mentioned above the booster plug (as well as similar clones) make the fueling system think the intake air is colder/denser than it really is. The electronic fueling system in the BMW uses the IAT (Intake Air Temperature ) sensor to trim the OPEN LOOP fueling to correct for intake air density. The colder the fueling computer thinks the intake air is the more OPEN LOOP fuel it adds (only up to a point). The max rich fuel trim available is usually capped at a point below catalytic converter damage (at least at moderate to warm outside ambient temps)

 

 

On these narrow band fueling systems like the BMW uses-- in closed loop it “IS IN CLOSED LOOP” so the IAT isn’t used for “closed loop” fueling calculations. The IAT is still used for spark trim in closed loop though.

The only dog leading the fueling sled in closed loop is the 02 sensor(s). SO, things like the booster plug have no effect on closed loop fueling control.

 

The second it reverts back to open loop then the IAT info is used again. SO, this is the area that a booster plug can help a little. They usually go open loop as the throttle is moved so in THEORY devices like the booster plug can richen the fueling a bit on throttle-up movement or light acceleration.

 

The hexhead BMW doesn’t seem to be a good candidate for IAT spoofing devices like the Booster Plug. The hexhead is already pretty good at throttle-up fueling and does run in closed loop a lot of the time. I have run home built multi position IAT spoofers on my personal 1200 hexheads since I have owned them & am hard pressed to tell when it’s set at stock or 20° below zero or in between.

 

What I have found in spoofing the 1200 hexhead at real low ambient temps (like starting at or below 15°f) is it drives the starting fuel control crazy and severally over fuels to the point of black smoke and unburnt fuel smell. My personal concern under these conditions is cylinder wash and crankcase oil dilution. I would suggest that anybody running a intake air spoofer on a 1200 hexhead in real cold weather to add a switch to deactivate it in cold weather especially for cold starts & cold roll-off.

 

These booster plug devices really come into their own on the early open loop ONLY fueling systems like the early non 02 electronic systems used on the Ducati. I have a Ducati that is a completely different riding bike when I spoof the intake air sensor. I think this is where things like the Booster Plug or other IAT spoofers get a good reputation as working as advertised.

 

So far the best thing I have found on the 1200 hexhead for increased light throttle acceleration and smoother throttle control is simply disconnecting the 02 sensors. That does make a notable difference as that forces open loop all the time. The open loop fueling on the heaxhead seems pretty darn good and tends to be a well executed. The down side is worse fuel economy (it can be quite noticeable).

 

 

 

[RoSPA_man]

Okay, what is a booster plug?

 

Morning Bswag

 

 

 

So far the best thing I have found on the 1200 hexhead for increased light throttle acceleration and smoother throttle control is simply disconnecting the 02 sensors. That does make a notable difference as that forces open loop all the time. The open loop fueling on the heaxhead seems pretty darn good and tends to be a well executed. The down side is worse fuel economy (it can be quite noticeable).

 

 

Hi Dirt Rider

So the ideal might be to have a simple dash-mounted switch to break each of the O2 sensor circuits - or is that too simple?

Hugh

[dirtrider]

Afternoon Hugh

 

 

Yep, in theory anyhow.

 

Unfortunately you would need a switch & circuit wiring that adds little to no added resistance to the 02 sensor circuit(s). That’s a lot to expect from a cheap little switch that sees very little current to keep the contacts clean & resistance free.

 

It could be done with the correct components. Maybe better off with a dash switch controlled small micro relay for each side that is mounted close to the 02 sensors. Would need to totally waterproof and far enough from extreme heat to protect it.

 

 

[NewBlue]

The IAT and some spoofers are resistors, NTC type.

 

It's what the O2 sensors see when going from open to closed loop that will cause the adaptives to correct. If they are always trying to lean the mixture out when active, the fueling will shift across the board to run leaner. It keeps using the O2 sensors to see if they sweep as they should. When they do that's the new fueling. You can now reset the adaptives using the GS911 and it is recommended that you do after a tune-up.

 

Watch the O2 with a GS911 and you will see they are in closed loop and active very quickly.

 

The voltage drop sending O2 signals through switches or relay contacts will cause more harm then good.

 

The HO2S is ignored during acceleration so cutting or adding switches or relays isn't going to do you much good.

 

Maybe add a set of SU side-draft carbs.

 

Better yet, leave it alone, you won't get it better then BMW did.

[dirtrider]

.

 

The HO2S is ignored during acceleration so cutting or adding switches or relays isn't going to do you much good.

 

 

Afternoon NewBlue

 

Then it’s pretty obvious you haven’t ridden any of the hexheads with the 02’s disconnected.

 

Makes a noticeable difference in light throttle operation as it isn’t jumping on & off lean 02 control as well as the short term block learn is not based on the previous leaner 02 input.

 

Try it (running with disconnected 02’s) then post back.

 

[NewBlue]

.

 

The HO2S is ignored during acceleration so cutting or adding switches or relays isn't going to do you much good.

 

 

Afternoon NewBlue

 

Then it’s pretty obvious you haven’t ridden any of the hexheads with the 02’s disconnected.

 

Makes a noticeable difference in light throttle operation as it isn’t jumping on & off lean 02 control as well as the short term block learn is not based on the previous leaner 02 input.

 

Try it (running with disconnected 02’s) then post back.

 

No I have not ridden with the O2 sensor disconnected.

 

The O2's are there for one reason and that is to protect the cat.

In the days of CIS and an O2 controlled frequency valve disconnecting the sensor and setting the CO was the norm but not now.

On the BMS-K controlled hexhead it's not a good idea to disconnect it. The fueling system puts a lot of weight on it. Without the O2 operation it can't adapt for restricted air filter, worn plugs, slight vacuum leaks, etc. and it's main concern of keeping an overly rich mixture from destroying the cat.

Sometimes you just have to ride a bike and leave it alone, what seems like the miracle cure in the end causes more harm then good.

In the case of the O2 sensors, let them do what they do and your bike will be happy.

 

You offer a lot of help, wisdom, and insight but not in this case. 20 years of factory training tells me so.

Anyone can do what they want to their bike it makes no difference to me but telling them to disconnect an import part of the fueling system is just not a good idea in my book but then again YMMV

 

So, no, I won't be disconnecting them and reporting back.

 

With respect,

 

Newblue

[dirtrider]

Afternoon NewBlue

 

 

I hear you on keeping the thing stock, probably the best long term approach.

 

No doubt that keeping the 02’s operational is better for the cat but they already go open loop & stay open loop at high speeds and at throttle up and under high engine loadings. Long term idling is probably the place that the 02’s help the cat the most & we just don’t idle motorcycles that long at one sitting if not a police bike.

 

With all the people disconnecting 02’s & adding fuel controllers you know I’ve yet to hear of one complaint of a failed catalytic converter on the BMW boxer. Maybe they become a bit less active but I haven’t ever heard of one plugging unless the engine was a chronic oil burner. I do know of a guy that crushed one in the pipe area from jumping a curb.

 

I wonder if Power Commander knows about disconnecting the 02’s being an issue as their standard Power Commander for the hexhead requires 02 sensor disconnection. My dealer has installed a bunch of the Power Commanders on the heaxheads even while the bikes were still under warranty. Even the wide band kit for the Power Commander only uses the (single) wide band 02 for the learning part as it doesn’t use it to fuel-to while riding. You would think that if open loop fueling was an issue Power Commander would require cat removal as a requirement to install their controller.

 

I have a friend that has an 06 GSA with 106,000 miles on it and the 02’s were disconnected at somewhere around 10,000 miles. Maybe by now the cat is poisoned but that thing still runs out to over 125 mph so the cat definitely isn’t plugged.

 

I have you by a few years on lambda controlled fueling system as I started working with them in early 1975. Back then we didn’t have electronic fuel injection yet but used the lambda feedback to computer control enrichening solenoids in the carburetors. The first ones didn’t even do idle control just cruising at road load. All we had for cats back then were single bed bead cats that plugged up easily or fused the beads into lumps if over fueled. That was way before the planar-style 02 sensor was introduced so no electric 02 heat yet and the reference air was taken in at the sensor cap down under the vehicle in the dirt, water, and salt.

 

 

 

 

 

 

 

[Jerry Duke]

My 2005 ST was jerky at off-idle parking lot speeds. I installed a BoosterPlug and it is noticably better. I can pull the module easily and the difference is noticed by anyone that rides it before and after. I don't know much about open loop, O2 technology, etc. but I know there is an improvement and I'll keep the module.

[2xrboys]

Thanks to dirtrider for the photo, very helpful.

 

Have since ridden the bike with the power plug installed. It does change the manners of the bike in a subtle way. I have a full Remus exhaust with no cat. Without the PP, there was some exhaust pop on deceleration, that has changed to more of a rumble sound. Tried lugging it around 2,000 to 2,500 rpm in town and the bike now runs silky smooth at that speed, also seems more responsive accelerating just off idle.

 

I can understand the thought that the BMW engineers spent a lot of time getting it right and its not a good idea to change from stock. They were also working within the restraints of mass production, fuel economy and EPA standards. For me, the bike runs better with the PP so will leave it on.