Finished open loop ECU system

[Ncdan]

A couple months ago I requested assistance with an issue with my Calvin severely spark knocking on a hot day when accelerating  from 70-75 mph. It was the consensus of several of the guys that bypass of the o2 sensor and remapping was in order. One of our fellow guzzi buddies, from down under, volunteered to assist me with this feat.
First thing I did was to replace the factory crossover with the minstrel H pipe at which time I decided to plug the o2 hole and secure the sensor to the bike frame for possible future replacement if necessary.
Next step was the remapp which my buddy from down under walked my wife, who is the computer geek, through.
The first run the bike ran great but had some popping when decelerating and we did an adjustment last nite to deal with that but due to weather haven�t got to check the results yet. At this point the Calvin feels stronger and one can feel a less restrictive Preformance however one can be tempted to over react to suddle changes when money has been spent for the change, I�m sure some can identify with this:)
Now my hope is that I don�t loose the great gas mileage the Calvin was offering, 50- 53 MPG on a constant bases. Now it will take some time to come to a collusion as to the final and complete results of an open loop system as apposed To a closed system.

[guzzisteve]

You should still get 45-50mpg on a CalVin if properly tuned.

[Ncdan]

You should still get 45-50mpg on a CalVin if properly tuned.

Thanks for the response Steve. I�m more than willing to give up at least  5 mpg for the better Preformance. A cooler motor and better breather is worth a little trade off for me. I’ll know the MPG hopefully in a few days if the rain and snow will hold off a bit.

[Sheepdog]

Nice sound, too...without being loud.

[Ncdan]

Nice sound, too...without being loud.

Absolutely Sheep. I was getting a little deceleration popping from around 3000rpms down. We tweaked it last night mostly stopped that. Now down to around 2000rpms it�s not popping and maybe a little puffs from 2000 until pulling the clutch in. I think what�s left is normal considering the third muffler has been removed. What u think?

[rodekyll]

I get that same light popping on light throttle/coast/decal with the 1200 engine.  I'm not ready to deal with it yet, but it would be interesting to hear what you're doing to solve it.

[pete roper]

What ECU are you running David?

[Ncdan]

I get that same light popping on light throttle/coast/decal with the 1200 engine.  I'm not ready to deal with it yet, but it would be interesting to hear what you're doing to solve it.

Rode, my buddy down under made an adjustment to the map last night and for the most part fixed the issue. From upper rpms to full deceleration down to around 2000rpm there is no back pressure popping. From 2000 to pulling the clutch in for the stop there’s a subtle and probably normal putting that can be heard due to the removal of the factory crossover third muffler to a minstrel h pipe. However it’s in no way annoying. The tweeting adjustments after the remapping change is very quick and easy as your person who  builds your map takes input from what you tell him your bike is doing and instructs you what to enter into your laptop that’s connected to your ECU to make the change necessary to correct the issue you are having. This is my first time doing this with a bike. Personally I could not have did it without my wife as one must have a good working knowledge of how to conduct fairly complex computer skills.

[mtiberio]

Open loop fuel injection: like a blind man tossing a bucket of water at someone shouting FIRE.

[scra99tch]

I get that same light popping on light throttle/coast/decal with the 1200 engine.  I'm not ready to deal with it yet, but it would be interesting to hear what you're doing to solve it.

Take note when you start to coast down a hill what RPM it starts at and when it stops when throttle fully closed.  Then increase that column of numbers by 5% (3.6 degree on my vintage) to start.  Just for informational purposes it took about an 8% change to delete all popping on decel  I don't know how an O2 sensor would change that if installed, I disabled mine. 

[Sheepdog]

I'll admit that I let Todd Eagan of GuzziTech re-map my Vintage ($250 is a screaming deal compared to the $800 for a reflash on my Beemer). I had him disable the closed-loop feature and map to accommodate a modified air box and Mistral Classic silencers/h-pipe. The result was extraordinary. Low speed fueling became a great deal more linear, no more popping on deceleration, and the engine now has a really sonorous exhaust note. It even seems to run cooler. I've always loved my CalVin, but the re-flash really improved her more than the price tag would indicate. Good on you for taking this on, Dan. It sounds like you're just about there...

[pauldaytona]

Open loop fuel injection: like a blind man tossing a bucket of water at someone shouting FIRE.

Well the closed loop that Guzzi uses is just there to pass regulations, not to get a better running engine.
If that was the case, a wideband lambda is needed.  And it should also work over 4500rpm.

[rodekyll]

What ECU are you running David?

Pete, this is that classic cluster I've been working with Beetle to develop.  It's a 1200 2-valve/dual plugged Breva engine running 1100 EV intake and injectors with a 15M ECU.  We've got it tinkered to a drivable state, but there is a bit of popping on overrun and decal.  Beetle has narrowed the offending rpm range.  It used to be idle <-> 2800.  Now it seems to come on at lower rpm -- 2200-ish. 

I've been eliminating other variables before taking the map back to him.  I don't see the point of taking his valuable time tweaking a map when I have other suspects to apprehend.  I just read a topic with a comment about the length of a pod filter v the diameter of the intake bellmouth.  According to the comment, mine is too short.  I'm not sure how that affects breathing, but it bears investigation.

[swooshdave]

Well the closed loop that Guzzi uses is just there to pass regulations, not to get a better running engine.
If that was the case, a wideband lambda is needed.  And it should also work over 4500rpm.

The first things people did with Hinkley Triumphs was rip out the O2 sensors. Ran so much better.

[Ncdan]

Open loop fuel injection: like a blind man tossing a bucket of water at someone shouting FIRE.

Could you offer a little more information in regards to pros or cons to that opinion please?

[mtiberio]

Could you offer a little more information in regards to pros or cons to that opinion please?

at least a carb (or closed loop injection) has some built in feedback. open loop injection simply squirts based on a number of parameters, the sum of which are rarely ideal. Hence the blind part.

[Sheepdog]

Yes, but the closed loop parameters on the Vintage are consistently lean (really lean) throughout it�s operating range. What is more, any corrections to the closed loop mapping (think O2 Optimizer) will eventually be reversed back to factory settings by the CPU. Closed loop mapping only affects low rpms, anyway...the remainder (above about 3000 rpms) is open loop from the factory. Cooler running alone is a good reason to make this change...more linear throttle response at low revs just sweetens the deal. I think of low rpm closed loop FI mapping the same way I think of those aluminum plugs that bike makers cover fuel/air mixture screws on carburetors with; an obstruction to a proper running engine. Besides, I believe that only the Lambda sensor (the oxygen sensor) is disabled on the Vintage with a reflash. Temperature and air pressure sensors remain operational...

[Ncdan]

Yes, but the closed loop parameters on the Vintage are consistently lean (really lean) throughout it�s operating range. What is more, any corrections to the closed loop mapping (think O2 Optimizer) will eventually be reversed back to factory settings by the CPU. Closed loop mapping only affects low rpms, anyway...the remainder (above about 3000 rpms) is open loop from the factory. Cooler running alone is a good reason to make this change...more linear throttle response at low revs just sweetens the deal. I think of low rpm closed loop FI mapping the same way I think of those aluminum plugs that bike makers cover fuel/air mixture screws with; an obstruction to a proper running engine. Besides, I believe that only the Lambda sensor (the oxygen sensor) is disabled on the Vintage with a reflash.i Temperature and air pressure sensors remain operational...

That’s correct Sheep, the remap turned the o2 sensor off even though I did not put it back in the new H pipe which I simply plugged and wrapped up good and tight and zip tied to the frame in the event I or someone decides to replace in the future. There’s no doubt I’ve done the best for the calvin to get a pro to build a decent map for the bike. Also corrections can be easily made until a, perfect as possible, map can be obtained. However the closed loop system with the o2 sensor was in certain conditions producing issues that could even be harmful to a bike motor. I don’t figure I’ll ever go back. The last issue will be the effects on fuel mileage which I will hopefully be able to to find out when the weather allows. Maybe some folks that reads this post will chime in and offer some numbers they have seen from the changing of the loop system.

[Sheepdog]

I’ll start. I recently took a 600 mile road trip on (mostly) US and Louisiana highways. Cruising at 60-70 mph I averaged 47 mpg. Around town it drops down to 43-44.

[beetle]

at least a carb (or closed loop injection) has some built in feedback. open loop injection simply squirts based on a number of parameters, the sum of which are rarely ideal. Hence the blind part.

Your ignorance is astounding.

Let's see. On the CalVin, there's intake air temperature feedback, engine temperature feedback, and air pressure feedback. Later model Guzzi's even have MAP sensors. That's Manifold Air Pressure, because you wouldn't have known that.

Carbs have zero feedback. They can be accurately set for 1 (one) temperature and 1 (one) air pressure. They react to changes in manifold air pressure, they do not adjust anything.

[Kev m]

at least a carb (or closed loop injection) has some built in feedback. open loop injection simply squirts based on a number of parameters, the sum of which are rarely ideal. Hence the blind part.

Please explain why you think a carb has feedback?

For the record, ALL fuel injection systems calculate air fuel ratios based on parameters and the sum of which are still more ideal than carbs from a pollution standpoint.

Even systems designed to operate on O2 feedback operate in open-loop much of the time, only making additional adjustments based on feedback at idle and steady throttle.

You cannot approach the points of lean tuning and emissions standards of even an open-loop only EFI system with a carbureted motor without risking damage from running too lean at times.

There's a reason even open loop only EFI systems were used for a while.

And the ones I've owned ran brilliantly.

[Kev m]

Carbs have zero feedback. They can be accurately set for 1 (one) temperature and 1 (one) air pressure. They react to changes in manifold air pressure, they do not adjust anything.

Though you are correct with most points I must point out that constant velocity carbs use vacuum pressure diaphragms to control tuning through a tapered needle and main jet.

As such though they do not operate on any feedback, they DO self-adjust for ambient changes to altitude/density.

Oh and there was a dark time in the automotive industry between standard carbs and EFI where "feedback carburetors" were used, but they were not much more efficient/clean then carbs and early EFI systems eclipsed them so quickly that I don't believe the motorcycle, powersports, or marine industries ever bothered trying to utilize them.

[beetle]

Though you are correct with most points I must point out that constant velocity carbs use vacuum pressure diaphragms to control tuning through a tapered needle and main jet.

As such though they do not operate on any feedback, they DO self-adjust for ambient changes to altitude/density.

As I said, they "react", not adjust.

[Kev m]

As I said, they "react", not adjust.

Oh ok "Toe-MAY-toe, Toe-MAH-toe"

I guess semantics aside I would have called that "self-adjusting" but you are of course correct that's a "reaction".

[Ncdan]

I�ll start. I recently took a 600 mile road trip on (mostly) US and Louisiana highways. Cruising at 60-70 mph I averaged 47 mpg. Around town it drops down to 43-44.

That sound good. I figure the 50+ I was getting was due to it starving for fuel. I�m not a real big fanatic over fuel mileage however I am over performance. I don�t want a racing machine I just want what I ride to give all it has to offer. I�m going to have to wait a bit to get some MPG results as the rain and snow is coming in tomorrow and over the weekend. Bottom line for me when you have a knowledgeable tech building your map it can be tweeted until perfection is obtained and my guy is definitely on top of the game in the field. I ant skeered:)

[beetle]

Oh ok "Toe-MAY-toe, Toe-MAH-toe"

I guess semantics aside I would have called that "self-adjusting" but you are of course correct that's a "reaction".

I don't want to come across as being pedantic, but I am, so I can't help myself.   

[Kev m]

I don't want to come across as being pedantic, but I am, so I can't help myself.   

I resemble that remark. [emoji56]

[mtiberio]

Your ignorance is astounding.

Let's see. On the CalVin, there's intake air temperature feedback, engine temperature feedback, and air pressure feedback. Later model Guzzi's even have MAP sensors. That's Manifold Air Pressure, because you wouldn't have known that.

Carbs have zero feedback. They can be accurately set for 1 (one) temperature and 1 (one) air pressure. They react to changes in manifold air pressure, they do not adjust anything.

Ha! Thanks for that. What you call react I call adjust. The amount of gas coming out of the needle jet is based on the velocity/vac within the venturi. That is a feedback system. In an open loop system you do not get that. But please keep talking.

[Kev m]

Ha! Thanks for that. What you call react I call adjust. The amount of gas coming out of the needle jet is based on the velocity/vac within the venturi. That is a feedback system. In an open loop system you do not get that. But please keep talking.

Respectfully that's not what anyone in the industries call a feedback system. The very definition of a feedback system is one that adjusts to sensors that monitor it's open performance through oxygen sensors. I.E. it's a state that creates a data loop based on how good a job it is actually doing.

CV carbs, like open loop EFI systems only "react" to external forces like temperature/pressure.

And as stated earlier even open loop EFI systems are more precise in their fuel delivery than even CV carbs.

[beetle]

Ha! Thanks for that. What you call react I call adjust. The amount of gas coming out of the needle jet is based on the velocity/vac within the venturi. That is a feedback system. In an open loop system you do not get that. But please keep talking.

What can I say? You're wrong. A carb is a simple mechanical device. The induction vacuum acts as a force that has an effect on the mechanisms of the carb. The carb mechanism does not measure the air pressure acting upon it to change the fuel output accordingly. It reacts.

In an open loop fuel injection system, the ECU gets data from the phase sensor, air temperature sensor, engine temperature sensor, air pressure sensor, et al, then calculates the injector pulse width. Nothing 'blind' happening, but yes, still a reaction. Unlike carbs, however, it can be made to work at any air temperature or pressure.

In a closed loop system, the above sensors still provide input, but when lambda is active, the O2 sensor input is used by the ECU to trim the fuel to a predefined range. As fuel is added or subtracted, the O2 sensor output signal changes so the ECU can trim again. Feedback.

In a narrowband arrangement, as is every EFI system from the factory, the fuel is trimmed to a range that meets emissions standards. That's an AFR of 14.5 to 15.1, approximately.

Surely you must also know that EFI systems operate in both open loop and closed loop systems from the factory? The closed loop operates below ~4000 RPM and only when the engine temperature is above 55 degrees Celsius. Above 4000 it's open loop! When the engine is below 55, it's open loop! And at idle, too. Open loop. Oh, the horror!