Technical knowledge ???

[Alex-Corsa]

Never found the cause of the raw fuel but it has not recurred. I did notice some choppy acceleration in very hot weather about 1500 miles later and reset everything again. It seems they are rather touchy to temperature and settings and need to be fiddled with occasionally. Overall though, in temps below about 95, once things were dialed in the bike runs great.

 

The TB synchronization has to be done in sertain Engine tempratres.At the instructional workshop Guzzi video

I have the 53'+ C' degrees is stated , generally I would say that 53-83 C' degr. engine temp. should be then when synchronising the TB's and setting idle

Once set right you don't have to fiddle with it often (except for hobby-Guzzihondria issues.. )

[Greg Field]

Current price on sensor holders is $32.95. I've got 'em if anyone needs one. Email me here or at work (parts@motointernational.com). Note: I'll be in Milwaukee for Friday-Monday.

[Alex-Corsa]

Oh... what is TPS voltage?

 

TPS voltage is the Throttle Position Sensor voltage. The TPS (sensor ) is located at the top of your right Throttle body with 2 screws.This sensor gives output in voltage and determines to the ECU where or in which position the trottle is..Higher voltage higher throttle degree openings. When this is calibrated right a 0 degress (150mv +-10) and at 3.8 throttle pos degrees around 550mv (for the V11)

Simple hint about it is Leave it alone ,especially the screws attaching it to the throttle body a small movement of screws is likelly to affect the pot even a tiny bit This pot is very sencitive and even a tiny move on it's base ,will change the output voltage dramatically and you don't want this.Only for someone with the practical experience is something to deal with.

TPS.pdf

 

Greg, do you know the resistance values for corresponding temperatures for that temp sensor? I haven't found a chart anywhere.

 

You mean these , Air and Oil temprature sensors output

SensorOutput.zip

Taken from the V11 manual

[richard100t]

Can anyone tell me the need for a crossover pipe at all? Is it for performance or emissions, or both? It would seem to me that you should be able to run a pipe from the head right to the pipe. There must be a reason for the crossover because I havent seen anyone eliminate it.

[Guest ratchethack]

Can anyone tell me the need for a crossover pipe at all? Is it for performance or emissions, or both? It would seem to me that you should be able to run a pipe from the head right to the pipe. There must be a reason for the crossover because I havent seen anyone eliminate it.

Richard, exhaust gas flow is a complex topic and I don't pretend to understand it more'n a duffer's chip-shot beyond the basics. I first picked up the concepts whilst doing a top-end on a 1969 A65 BSA, the first year BSA offered crossovers along with greater valve overlap for midrange performance. These crossovers were located immediately below the head and tended to leak almost as badly as the ones on the V-11's. Depending on design, crossovers can be located close to the head or farther downstream, or in both locations. While crossovers can make a considerable difference relative to non-crossover engines, I think that most of what is believed here and cooked up for use on road and track alike as far as crossover design, is that the designs are usually based partly on hard science, partly on superstition and voodoo, but in larger parts on trial and error.

 

Without getting too far over me own head , exhaust valve opening and closing causes waves of compressed and relatively uncompressed pulses travelling down the length of the exhaust pipe. By adjusting the length and diameter of pipes to match cylinder head design, which involves such considerations as crankpin layout, valve overlap, valve duration, valve timing, and many other aspects of engine design (more info here: http://www.hotrod.com/techarticles/cam_lob...ine_angle_tech/ ), engine designers and tuners plumb exhaust very carefully. The density and quality of the fuel charge in the cylinder head can actually be manipulated via scavenging effects with a crossover, with the goal of enhancing desired torque and/or power characteristics over non-crossover engines by matching up the power pulses with the intervals between them in alternate cylinders for desired output effects, including improved idle characteristics made necessary by increased valve overlap.

 

Crossover effects all come into play in the same way with a two-into-one exhaust such as on the Griso. The Griso's "crossover" makes use of the same principles, but with only one exhaust.

 

A guy named Ott, who's evidently the proprietor of a Porsche 928 go-faster shop offering his own crossover design, has put up a fairly enlightening intro discussion on exhaust pipe diameter, single vs. dual exhaust, and crossovers for 90-degree engine layouts here: http://www.performance928.com/cgi-bin/page...name=exhaustuPp

 

So to answer your question directly, I would say that crossovers are used for the purpose of improving both performance and emissions, though the emphasis for all practical purposes is on performance.

[Dan M]

 

You mean these , Air and Oil temprature sensors output

SensorOutput.zip

Taken from the V11 manual

 

EXACTLY! Thanks Alex

[dlaing]

Can anyone tell me the need for a crossover pipe at all? Is it for performance or emissions, or both? It would seem to me that you should be able to run a pipe from the head right to the pipe. There must be a reason for the crossover because I havent seen anyone eliminate it.

I eliminated the crossover on my V65SP, and it seemed to work fine and have a cleaner sound.

I might like to do the same with my V11, but keep in mind the cylinder fueling offsets programmed into ECU were built around a stock crossover and presumably stock mufflers.

Obviously people get great results going to aftermarket crosssovers, but the best results if you eliminate a crossover will probably occur after remapping the cylinder offset.

I use TuneBoy for remapping the ECU, but PCIIIUSB models can also handle cylinder offset.

I think the result of no crossover would be a little less power, more at high rpms, unless your mufflers are very free flowing, but potentially better balance between cylinders.

But I am just guessing about all that as nobody seems to have done it and documented before and after dyno tunes.

[Guest ratchethack]

Can anyone tell me the need for a crossover pipe at all? . . . I havent seen anyone eliminate it.

Richard, FWIW, I might've mentioned the experience of my Pal, Le Mans Dan. He got tired of dealing with the leaking front crossover on his '04 LM, and had the header junctions for the crossover welded shut. Aside from no more leaks, he can't tell any difference. He has a Stucchi rear crossover in place of the stock expansion box.

[Skeeve]

Can anyone tell me the need for a crossover pipe at all? Is it for performance or emissions, or both? It would seem to me that you should be able to run a pipe from the head right to the pipe. There must be a reason for the crossover because I havent seen anyone eliminate it.

 

Well, in the case of the stock pre-muffler, it's there for emissions. NOISE emissions! By allowing both headers to feed into both mufflers, the shared volume is less restrictive than a straight 1-1 connexion, so you end up with mo' betta' performance for the same sound level. In the case of the Stucchi, it's performance, for even tho' it does the same sharing of exhaust between the stock mufflers, its design is such that you get more performance out of the same job...

 

So the precise answer is "both," I guess...

[mark.gilmore]

I have seen a pic of the Guzzi X-over cut in half, has anyone got a :pic:of a Stucci inside, not that anyone would cut one up.

[belfastguzzi]

I have seen a pic of the Guzzi X-over cut in half, has anyone got a :pic:of a Stucci inside, not that anyone would cut one up.

?? What are you expecting to see ??

[Guest ratchethack]

I have seen a pic of the Guzzi X-over cut in half, has anyone got a :pic:of a Stucci inside, not that anyone would cut one up.

As BFG suggested, there's nothing on the inside of the Stucchi that can't be seen from the outside, other than carbon black.

[dlaing]

I have seen a pic of the Guzzi X-over cut in half, has anyone got a :pic:of a Stucci inside, not that anyone would cut one up.

As was just suggested, I expect it is basically just what you see on the outside and that the crossover area is maximized. Of course the crossover could be partially blocked, but I doubt it.

It is interesting that the Mistral crossover is much more of an H crossover than the Stucchi, and the result seems to be greater mid range at the expense of top end. I suspect this is from less flow actually crossing over, as it more easily crosses over in an X crossover.

I suspect the OEM crossover results in the biggest hole in the midrange because of the crossover allows flow to expand and find the least path of resistance through either muffler, but at the expense of the cylinder flows interfering with each other.

The Stucchi also splits the flow to maximize top end power, but it keeps the direction flowing outward so there is less cross cylinder interference.

Of course the advantage of the OEM vs the Stucchi is the noise suppression, and maybe lighter weight.

It would be nice to have an X crossover that you could adjust the crossover section according to RPM, with it closed for RPMs below 5000, but opening up for the higher RPMs.

But it is difficult to predict results.

I recall someone posted how the OEM mufflers did not work great with the Stucchi, something I wouldn't have and didn't predict. I was hoping it would have worked, because it could have meant more power with a reasonable noise level.

[Guest ratchethack]

Of course the advantage of the OEM vs the Stucchi is the noise suppression, and maybe lighter weight.

The Stucchi is probably somewhere around half the weight of the stock crossover box.

I recall someone posted how the OEM mufflers did not work great with the Stucchi, something I wouldn't have and didn't predict. I was hoping it would have worked, because it could have meant more power with a reasonable noise level.

By my experience it works just fine -- exactly as expected. I ran my Stucchi crossover with OEM airbox and stock mufflers for nearly a year before going to FBF oval carbons, so I was able to make direct comparisons between the stock crossover and the Stucchi without the effects of any other changes. The Stucchi was slightly louder and produced a more mellow, deeper sound. It also gave a noticeable boost to the torque curve in the midrange with the stock mufflers and airbox, particularly at the notorious "dip" starting at 4500 RPM.

[dlaing]

The Stucchi is probably somewhere around half the weight of the stock crossover box.

 

I ran my Stucchi crossover with OEM airbox and stock mufflers for nearly a year before going to FBF oval carbons, so I was able to make direct comparisons between the stock crossover and the Stucchi. The Stucchi was slightly louder and produced a more mellow, deeper sound. It also gave a noticeable boost to the torque curve in the midrange with the stock mufflers and airbox, particularly at the notorious "dip" starting at 4500 RPM.

Thanks Ratchet.

I guess when someone told me the Stucchi was heavy, they meant robust, not heavy.

My apologies.

But I swear someone posted a disappointing dyno of the OEM LaFranconi's with the Stucchi....I just can't find it.