JuhaV

Hi, Anyone have experience how high rpms a Sporti / V11 engine can tolerate before the valves start to communicate with the piston tops ? Where does the rpm limiter of a stock V11 cut out ? I know that there is not much to gain going beyond 8000 rpm, but I would like to know where the physical limit really sits. I have a My16M ECU unit where one can adjust the rpm limit freely and my engine seems to go rather willingly above 8000 rpm. I have taken it up to 8750 rpm without problems a couple of times, but it could go higher. Any experience on this ? br, JuhaV

Hi Al, Do not worry. This axial free play is completely normal. It will become somewhat smaller when the chain and sprockets of the timing gear are in place, but it will not disappear completely. If you study the crankshaft bearing assembly, you can see that there is no way that it could provide accurate end float. This would require some kind of axial bearing surfaces in the crank and/or use of thrust type bearings. During use the crank won't feel any signifant axial forces. My understanding about this issue is based on this kind of experience br, JuhaV

What is it then ? br, JuhaV PS. added some new pics on my site.

Let us hear what you learn from them. I am also interested to hear how are your current valve stems and valve guides doing. I was rather surprised to see that the original ones seem to be quite soft stuff and prone to wear out quite fast. In my case 33 000 km were enough to send them into the bin. br, JuhaV

Hi, I decided to try Denso Iridium plugs just for the heck of it. I persuaded myself to buy these high tech things thinking that the because those smaller diameter tips run much hotter, therefore there should not be any carbon build up issues with these. br, JuhaV

Yes, I really like the quality of the Termignoni exhaust system. Anyway, this is the exhaust manufacturer that provides their systems, for example, to those numerous Ducatis. Not sure if that fact directly reflects the quality, but at least it makes their systems rather pricey In this case I simply thought that the Termignoni people choose to have the larger header pipe diameter (creating that step) instead of a smoother joint with the exhaust port (smaller diameter header, but no step). Because they did not have the possibility to change the exhaust port diameter in the head, so they went the less restrictive route of the two possible choices available. By the way, I finally checked out the original Sporti header and it has the same inside diameter than the exhaust port. Therefore, it does not create any step at that location were I had the step with the Termignoni header. However, there is a signifant widening of the original tube, i.e. even a bigger "step" at about 50 mm downstream from the start of the header. Don't know if this is really because of flow considerations or simply because of manufacturing reasons. This step is about 4-5 mm in height and could really create some reverse flow prevention effects. Anyway, I can appreciate the reverse flow blocking scheme, but somehow I think (by intuition ) that that step would need to be somewhat farther away from the exhaust valve to have a real effect. The one in the original header could have some effect. Maybe someone can shine some more light into this ? Because of its pulsing, non-steady nature it seems that understanding the flow in and out of the engine is really challenging. Even a flow bench cannot simulate such a situation perfectly, because the hot combustion gases will in reality behave in a different manner than a cold steady air flow. Also, any change in the inlet system or exhaust system will change their resonance behaviour. Nah, my changes there were rather minor and I am quite confident that I will not see any very significant effects. My primary aim was to get the two heads in better balance compared to each other. My thinking here is that if one makes a relatively little change in the shape of the port there where the port area/diameter is already quite large (away from the vicinity of the valves), then you propably cannot completely mess up the results. On the other hand, going closer to the area of the valves is completely another story, because there the flow is forced to go through a much narrower cap and the port and the valve shape can have very significant effects on that flow. There must be some very well performing Guzzi heads out there. Would love to hear some details how they were modified ! br, JuhaV

Hi Skeeve, Thanks for your input. Actually, I heard about the same thing before I dremelled my way into the exhaust channel However, my reasoning here was the following. It seemed that the step was due to the Termignoni adapter (having larger inside diameter than the channel) and if using the original pipe there would not be such a step at all ? I did not check this carefully out, but maybe someone can confirm if the standard pipes create such a step there or not. Considering that Termignoni people really know what they are doing I thought that the step might be there for purpose, but ... The step had a "height" of about 1-1.5 mm and it was symmetrical all around the channel. Now, the step is down to maybe 0.5 mm. Which way is roof ? Is it opposite side compared to the valve opening ? We will see how it goes in practise. I will report here when I get the bike running and the snow is gone from the local roads. Before doing this porting, I asked around locally a little and there seemed to be a wide variety of opinions how to perform porting in a Guzzi. Regarding the exhaust step issue, for example, there was opinion both against and favour of removing the step. I guess, I took the middle road there Learning by doing, JuhaV

Hi, Reasonable or not, I have now performed some mild head porting to my Sporti. I have written a few words about that on my webpage, so if the net result proves to be less power than before, so we all know what route not to take Take a look if interested. br, JuhaV

I went through the earlier threads dealing in quite detail this issue and found out that Al has these pods RU-1780. These seem to have an integrated flange tube so there is no need to destroy those original plastic airbox tubes. I will check these out. br, JuhaV

Thanks Jason, I speculated that I could squeeze that wider flare part inside the pod and get the pod tightened to that straight part behind the flare. Those stacks are quite soft material so this might be viable. But as you say, if there is no evidence to receive any benefits from this, it is easier to mount the pods directly to the injector bodies. br, JuhaV

Hi, I also consider going for the pods because of the somewhat "lighter" look of the bike. And easier access of the rear shock adjustments. Does anyone know whick K&N pods could be attached to these plastic "trumpets" that are part of the original air box ? I would like to retain these in order to have nice and smooth tunnel for the air to be sucked in. Mine is a Sport 1100, but I suppose V11 dimensions are about the same. br, JuhaV

Attempting to find out how Dynojet stuff is really working, I took a quick look into patent databases and found these public documents that might be of some interest to some of you. US6745620 seems to disclose how Tuning Link Dynos operate. US6681752 deals with the use of wideband lambda sensors. Those attachments should contain full pdf-versions of these documents. Enjoy, JuhaV US6745620 B2 Automatic tuning of fuel injected engines Abstract: A method and apparatus for automatic tuning of fuel injected engines includes an air-fuel ratio sensor, a load device for controlling engine RPM, a digital computer and a display device. The digital computer displays a plurality of throttle positions to an operator who sets the throttle of said engine to correspond to said display of throttle position. The digital computer varies the engine RPM over the operating range of the engine to determine corresponding map values for storage in an injector signal modifier. US6681752 B1 Fuel injection system method and apparatus using oxygen sensor signal conditioning to modify air/fuel ratio Abstract: A method and apparatus for externally modifying the operation of a closed loop electronic fuel injection control system that is normally used with a standard oxygen sensor, which method and apparatus includes replacing the standard oxygen sensor with a wide band oxygen sensor. The signal from the wide band oxygen sensor is processed in a first signal- conditioning module and coupled to the input of the electronic fuel injection control system. The first signal-conditioning module simulates the appearance of a standard oxygen sensor to the electronic fuel injection control system. In a second embodiment, a method and apparatus for externally modifying the operation of a closed loop electronic fuel injection control system that is normally used with a wide band oxygen sensor, includes intercepting the signal from the wide band oxygen sensor in a second signal-conditioning module. The second signal-conditioning module receives a first current from the wide band oxygen sensor and provides a second current to the electronic fuel injection control system.

Hubert, I really don't have any deeper insight how the newer usb PC's work, so they may work precisely the way you describe. It makes a lot of sense. Then, the PC needs to have its own base map that is bike model specific. Dynojet needs to have some way of extracting/recording this info from some individual bike or to get it from the manufacturer. br, JuhaV

That's too bad, because it would certainly help people to dial in and try out corrections by themselves. Yes, but with the base map I was referring to the original map in the ECU. As I understand PC does not change that map but only finetunes the control signals going to the fuel injectors. So, the control signals are always affected both by the original ECU base map and the "overlaying" PC correction map. If the PC map is all zeros, the fuel injection is solely by the ECU base map. If one would know both the original ECU map and the scale of the PC map, then we could calculate the injection values in milliseconds to make them more comparable with other bikes (assuming same injection pressure and injector size). Therefore it is very hard to say how reasonable the PC correction map looks if we don't know how "spiky" the original ECU map is. We can only see where the original map needed some correction, but we cannot say in absolute terms how big that correction has been. br, JuhaV

This is the way I have been thinking all the time. This is also very clearly explained at Cliff's www-site. Nope. This is important because to get it correct you need to move along the breakpoint lines when tuning. Breakpoint lines are going vertically and horizontally via the corners of that square those four adjacent cells are forming. If you don't do that and you tune somewhere inside that square, then you will change one of the four corner cell values in excess to get the average at your tuning point somewhere inside the cell correct. When you then move within that square in a different location, you will get an incorrect average value. It depends then on the amount of rpm and throttle breakpoints how big error there will be. br, JuhaV

Well, I am not familiar with Power Commanders, but I think that we would need to see both the original map from the ECU together with this PC map in order to know what the "effective" map really is. As I understand this PC map somehow multiplies or adds with the original map point by point ? So if we have in the original map at 5000 rpm & 50 % throttle value x and the PC map has in the same spot value y, the effective fuel injection value is x +y, or more propably something like x + x*y/c. If those PC map values are %-values (c=100) which would make some sense, then if y = 10 we would have simply x + 0.1x., i.e. 10 % enrichment. If y=0, there is no change. With negative y-values we would lean the mixture in similar manner. What comes to averaging, I think that there needs to (or should ) be some interpolation because the PC map seems rather coarse. There are not so many breakpoints in the throttle or rpm values. If you know the "scale" of those PC map values it would help to understand does a value, for example, 26 in the map mean 26 % enrichment (sounds like too much) or only 2.6 % enrichment (sounds actually somewhat more reasonable). Maybe this info is available somewhere in PC www-sites. br, JuhaV

Yes, that was my question. I have some difficulty understanding that having those "outrageous " values in the map is really an acceptable thing, because as Cliff has pointed out, the ECU is most propably doing some weighted interpolation whenever defining values between the breakpoints. Another thing is that you say that you would not achieve "a same looking map tuning on a different occasion". It sounds a bit peculiar to me to see that even if you are claiming to tune with very high accuracy for power, then the actual final outcome, the map, will be different in different tuning occasions. br, JuhaV

Yes, I understood that these are injection pulsewidth values stored into the ECU. What I was after was that if you make tuning runs, lets say, today and again after a couple of days/weeks, would you have those spikes in the same places and with similar magnitude ? If these are somehow related to resonance phenomena in the inlet or exhaust side, different environmental/engine temperature, air humidity/pressure or any other change (fuel quality) in the system could have significant effect especially on those resonance points. In other words, is it possible that striving towards a very accurate map under some specific circumstances could lead to such a map that it is well suited only to those circumstances. I must add that, at least what comes to Guzzis, I do not really believe that oil/air temp and air pressure sensors together with the original compensation algorithms are doing a perfect job in compensating for the changing situations. br, JuhaV

Interestingly large "spikes" in those maps. Are these because of some kind of resonance phenomena in the gas exchange ? Were these really repeatable during the tuning process ? br, JuhaV

Hi Paul, Does this mean that you can use it in a closed-loop mode ? Have you already considered what kind of lambda probes you are going to use ? The unit looks very nice, although the price is pretty high ! br, JuhaV

Hi, How about if you open the throttle slowly wide open and therefore let the engine rpm rise more slowly ? Can you say that the fuse blows at some certain rpm or is it really got to do with the rapid opening of the throttle ? br, JuhaV

Well, the above mentioned controller should not be taken to present an ECU, because it is only the electronic "drive unit" that is needed with all modern wideband lambda sensors. The output of this controller goes then to an ECU, and, at least according to some people here can be used succesfully for closed-loop control Among other sources, Bosch Wideband Oxygen Sensors discloses how these devices basically work. In short : A wideband sensor combines an oxygen-sensing "Nernst" cell with a "pump cell". The Nernst cell senses oxygen in the same way than a conventional narrow-band O2 sensor does. Let's simply think that it is a narrow-band sensor. As we know, this can only give a gross rich-lean indication of the air/fuel mixture, but it measures very accurately stoichiometric situation (where sensor signal switches rapidly from low to high voltage). The trick of the wide-band sensor is in the combination of the traditional narrow-band sensor and the pump cell. The pump cell can either consume oxygen or consume hydrocarbon fuel in the pump cell cavity, depending on the direction of the current fed into the pump cell. Now, a small sample of the exhaust gas passes into the pump cell, where the "traditional" Nerst cell narrow-band sensor is located. That exhaust gas is either rich or lean and both conditions can be indicated by the "switching" type narrow-band sensor. Based on the narrow-band sensor indication, the pump cell is fed with positive or negative current to either consume free fuel or free oxygen from the pump cell. When the free oxygen or free fuel has been neutralised, the narrow-band reference cell will indicate stoichiometric situation. The pump cell current (which is a measure of the number of electrons used in the chemical reaction) required to produce this equilibrium is a measure of the Lambda or Air Fuel Ratio. The controller mentioned in the above articles is simply the electronic drive unit to provide this current, and the same controller provides an output determined on the basis of this current and that output (voltage) relates to the lambda value. In other words, the pump cell consumes either fuel or oxygen to "hit" the stoichiometric situation that a narrow-band sensor situated inside that cell is able to accurately indicate. The amount of current needed in consuming fuel or oxygen, tells what the original A/F ratio was. The modern probes are able to perform this measurement in 100 ms. I hope this helps to see why wide-band lambda probes are taken to have at least certain capabilities to measure beyond stoichiometric situation. - JuhaV

As far as I understood Cliff's ECU is not running full closed loop, but partial closed-loop. Cliff, if I am wrong here please rectify. Sorry to repeat this, but I think that it is important to have this detail correct. When saying "partial" I mean here the following options : 1) Partial map closed loop = in some parts of the map ECU performs closed loop adjustment to the mixture and in the other parts of the map the system is in open-loop mode. User can choose where to be closed loop and where to be open loop. 2) Partial adjustment closed loop = lambda sensor is allowed to cause only a certain amount correction to the injection values, let’s say plus/minus 15 %. The base values are always taken from the map. The map can be user edited. 3) Multi-target closed loop = there can be different O2 target values for different parts of the map. These are also freely editable. When you have a wide-band sensor coupled with such an ECU, you are quite happy even with a base map that is somewhat off (not >> than 15 % off, of course). And the best thing is that you are able to improve your base map very easily. I have used a My16M in closed loop mode over 10000 km in my Sport 1100. I can only say that the bike runs much better with My16M than with the original Weber Marelli Unit. I have tried the original, Will Creedon and Termignoni chips and the bike has been properly set up. Further, the bike runs even better with MY16M in closed-loop mode br, JuhaV

I can't say that I have read and understood everything in this threat, but is/was there actually someone here who has really been promoting FULL closed loop adjustment based purely on lambda sensors ? I still have the opinion that anykind of sensor in your exhaust is better than having no sensor at all. The info that your sensor gives just needs to be interpreted correctly by the ECU and used for finetuning the fuel injection. Some of that knowledge may be written permanentyl into the maps or not. I cannot see any other way to ensure that your engine performs correctly despite of the changing day-to-day, weather-to-weather, gas-to-gas situations. br, JuhaV

Mike Rich Motorsports Check it out. The site also contains the following notice : "Between February 1, 2005 and March 1, 2005 we will be in transit to our new location in Newfoundland, PA. We ask that you remain patient during this process-- we will, of course, attempt to return as many voice- and emails as possible once we have reestablished our offices." br, JuhaV