Hotrodding the GS - Page 11

def · 12-06-2010, 07:31 AM

While I have few if any complaints regarding the Motronic 2.4 on my '01 GS, I believe there are ways to eliminate detonation which occurs frequently on boxers of this vintage.

If I'm not mistaken, H-D uses a Delphi ECU which employs spark ionization to determine when detonation is occurring. During detonation, the impedance across the spark plug gap increases dramatically providing immediate warning of detonation, thus allowing instantaneous adjustment of fuel and timing to eliminate the detonation. Is is seamless and eliminates any need for knock sensor hardware.

Also, how about throttle by wire....I am surprised that BMW has not done this already. With such a scheme, throttling the boxer could be tailored by adjusting slew rates, tip in and tip out rates, etc.

TB sync could be incorporated easily into such a scheme.

What say you Poolside, JJ?

def · 12-06-2010, 07:50 AM

Experts, correct me if I'm wrong but our boxer's ECU brains have only four inputs;

1: Throttle position.
2: Lambda signal
3: Ambient air temperature
4: Engine speed

I know that engine oil temperature is also measured but I am unaware if this parameter is used by the Motronic.

That's not much information to work with considering an automobile has MAP and other additional inputs to work with when determining engine fueling needs.

Disco Dean · 12-06-2010, 01:17 PM

Quote:

Originally Posted by def

Experts, correct me if I'm wrong but our boxer's ECU brains have only four inputs;

1: Throttle position.
2: Lambda signal
3: Ambient air temperature
4: Engine speed

I know that engine oil temperature is also measured but I am unaware if this parameter is used by the Motronic.

That's not much information to work with considering an automobile has MAP and other additional inputs to work with when determining engine fueling needs.

Don't forget air density.

J_White · 12-06-2010, 03:39 PM

Yeah, I don't know what it has and doesn't - eager to learn though.
But I'm shocked if it doesn't have any input for atmospheric pressure

If no, from sea level to high mountain elevations the fuel would be
way off???

Dan Cãta · 12-07-2010, 12:40 AM

As I remember from older posts on this forum, you set your TPS one voltage at sea level and another voltage at mountain high. Because of air density.

Dan.

johnjen · 12-07-2010, 12:49 AM

Quote:

Originally Posted by Dan Cãta

As I remember from older posts on this forum, you set your TPS one voltage at sea level and another voltage at mountain high. Because of air density.

Dan.

I realize this may be asking a lot, but could you provide the link to that post?

JJ

Dan Cãta · 12-07-2010, 12:58 AM

Quote:

Originally Posted by johnjen

I realize this may be asking a lot, but could you provide the link to that post?

JJ

Sure.

There may be other posts but this is the one I found using Google.

Dan.

def · 12-07-2010, 08:02 AM

Quote:

Originally Posted by Disco Dean

Don't forget air density.

I guess I forgot. Where is the density sensor?

Disco Dean · 12-07-2010, 08:06 AM

Quote:

Originally Posted by def

I guess I forgot. Where is the density sensor?

i believe it is located inside the ECU as in most other modern bikes and cars.

space · 12-07-2010, 09:20 AM

Quote:

Originally Posted by J_White

Yeah, I don't know what it has and doesn't - eager to learn though.
But I'm shocked if it doesn't have any input for atmospheric pressure

If no, from sea level to high mountain elevations the fuel would be
way off???

Can't this be picked up from the lambda sensor? If the air is thinner than expected and the stoichiometry is off as a result, then the lambda sensor should detect that the engine is running too rich and adjust accordingly. Or vice versa for "too thick" air.

That would only work during closed loop operation, though. I'm not sure how this works during non-steady-state conditions. I defer to the tuner gurus on this thread....

Disco Dean · 12-07-2010, 09:32 AM

Quote:

Originally Posted by space

Can't this be picked up from the lambda sensor? If the air is thinner than expected and the stoichiometry is off as a result, then the lambda sensor should detect that the engine is running too rich and adjust accordingly. Or vice versa for "too thick" air.

That would only work during closed loop operation, though. I'm not sure how this works during non-steady-state conditions. I defer to the tuner gurus on this thread....

There are experts and I am not one BUT - I am pretty sure (anyone know for sure?) that most all current ECU's have a air density sensor within the ECU housing - that has been my experience and it is essential to have that to compare - air temp - air density - with the lambda which is post combustion. As air density is not completely corolated with air temp. ie. hot and high altitude. Moisture content... weather systems....

ollka · 12-07-2010, 09:42 AM

Never heard about air density meter but air pressure is measured in most of modern ECU's. It does the same in rough frame.

Poolside · 12-07-2010, 04:24 PM

Quote:

Originally Posted by mike54

You're going to be build these in your garage? That's the was Apple and HP started. Now we've got the iPone and Carly Fiorina. There's a bar to get over.

I'm hopeful here. All ears and waiting to see what is born/borne of this.

I know nothing about controls like the Motronic. But I'd be interested in hearing about how you're altering it's behaviour with out spoofing the inputs from the sensors. If you could put in in laymans terms.

Yea, built in my garage. You're right, there are some tough acts to follow.

To your question. Like I was saying in an earlier post, the 1st of these 4 upcoming devices does alter the air temperature sensor signal. In layman's terms, it is a spoof of the temperature signal.

But, two things are different about it. First, it's adjustable. Adjustability gives the rider a performance choice, and gives the device a wider operating range. Second, without that adjustability it will not work well with the 2nd, 3rd, and 4th, (so far) upcoming products.

The 1st device, the IICE Air, works on the air temperature. The air temperature controls the 'Open Loop' operating range of the ECU.
On the chart it's the BLUE box. (Link to Chart)
During open loop operation the altered temperature signal informs the ECU that the air is a little denser than it actually is, so it adjusts the mixture to match. The end result is the mixture is slightly rich relative to the actual air density.

The 2nd device, the IICE Cool, works on the oil/coolant temperature. The oil/coolant temperature controls the 'Transient Enrichment' feature, and also Overrun Fuel Cutoff.
On the chart it's the two VIOLET boxes. (Link to Chart)
Transient Enrichment is where throttle response comes into play. The hesitation while opening the throttle is gone. When someone says "I like how the motor feels" they are talking about off/on transition throttle response.

Besides off/on throttle transitions, the other big area where transient fuel makes all the difference is when pulling away from a stop. You know how it is, you let out the clutch and it almost feels like the motor is going to stall. It goes soft. You must open the throttle more, and fan the clutch to get rolling. Ridiculous.

With the right amount of transient enrichment the motor just torques away from a stop. It gives the feeling of having more power than it needs. Beautiful.

The Motronic does have some very nice operating states, trouble is they're never there when you need them. Well, we're fixing that.

itsatdm · 12-07-2010, 07:35 PM

Interesting stuff, even to the owner of one of the lesser BMW's. I have one of the "fool the ECU air temps sensor devices". I have noticed if I chop the throttle suddenly followed with partial throttle, I get a noticeable stutter in my get along. I think you just explained it.

Lobby · 12-07-2010, 08:00 PM

I've got an '05 12GS, and while I like the engine much more than the 1150 models I had (smoother and more powerful), there's a bunch I don't like about it.

When I give it gas to accelerate (normally from lower RPM's - say 3500), it sure seems to take a lot to really get going.

Yet when it's about 5000 rpm, now matter which gear it's in, the bike zooms.

I would like this dead spot in the middle of the RPM band to go away.

But, I'd also like to keep my good fuel economy.

12-07-2010, 12:40 AM	#155
Dan Cãta Beastly Adventurer Joined: Jun 2008 Location: Cluj, Romania Oddometer: 1,465	As I remember from older posts on this forum, you set your TPS one voltage at sea level and another voltage at mountain high. Because of air density. Dan. __________________ R 1100/1150 Intake(Throttle body) repair kits - Now with nstructions!!! Waterproof HES (Hall effect plates) for R 850/1100/1150 beemers boxer-upgrades/webstore

12-07-2010, 09:42 AM	#162
ollka Usually lost Joined: May 2010 Location: Finland, Europe Oddometer: 114	Never heard about air density meter but air pressure is measured in most of modern ECU's. It does the same in rough frame. __________________ Best thing about a GSA is getting lost Wrrrroaaming around with GSA 2010 and Audi S5 SB

12-07-2010, 07:35 PM	#164
itsatdm NoMoTDM still Gary Joined: Jun 2004 Location: Columbia, Ca. Oddometer: 3,704	Interesting stuff, even to the owner of one of the lesser BMW's. I have one of the "fool the ECU air temps sensor devices". I have noticed if I chop the throttle suddenly followed with partial throttle, I get a noticeable stutter in my get along. I think you just explained it. __________________ BMW Motorrad USA customer service: "We make superior motorcycles and continue to improve them."

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12-06-2010, 07:31 AM	#151
def I have little to say Joined: Feb 2004 Location: The woods and mountains of Alabama Oddometer: 6,302	While I have few if any complaints regarding the Motronic 2.4 on my '01 GS, I believe there are ways to eliminate detonation which occurs frequently on boxers of this vintage. If I'm not mistaken, H-D uses a Delphi ECU which employs spark ionization to determine when detonation is occurring. During detonation, the impedance across the spark plug gap increases dramatically providing immediate warning of detonation, thus allowing instantaneous adjustment of fuel and timing to eliminate the detonation. Is is seamless and eliminates any need for knock sensor hardware. Also, how about throttle by wire....I am surprised that BMW has not done this already. With such a scheme, throttling the boxer could be tailored by adjusting slew rates, tip in and tip out rates, etc. TB sync could be incorporated easily into such a scheme. What say you Poolside, JJ?

12-06-2010, 07:50 AM	#152
def I have little to say Joined: Feb 2004 Location: The woods and mountains of Alabama Oddometer: 6,302	Experts, correct me if I'm wrong but our boxer's ECU brains have only four inputs; 1: Throttle position. 2: Lambda signal 3: Ambient air temperature 4: Engine speed I know that engine oil temperature is also measured but I am unaware if this parameter is used by the Motronic. That's not much information to work with considering an automobile has MAP and other additional inputs to work with when determining engine fueling needs.

12-06-2010, 03:39 PM	#154
J_White should be working Joined: May 2010 Location: NE Mississippi Oddometer: 319	Yeah, I don't know what it has and doesn't - eager to learn though. But I'm shocked if it doesn't have any input for atmospheric pressure If no, from sea level to high mountain elevations the fuel would be way off???

12-07-2010, 08:00 PM	#165
Lobby Viel Spass, Vato! Joined: Nov 2003 Location: San Antonio, Tx Oddometer: 25,808	I've got an '05 12GS, and while I like the engine much more than the 1150 models I had (smoother and more powerful), there's a bunch I don't like about it. When I give it gas to accelerate (normally from lower RPM's - say 3500), it sure seems to take a lot to really get going. Yet when it's about 5000 rpm, now matter which gear it's in, the bike zooms. I would like this dead spot in the middle of the RPM band to go away. But, I'd also like to keep my good fuel economy.