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GuzziMoto last won the day on January 3

GuzziMoto had the most liked content!

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About GuzziMoto

  • Rank
    "I live here"

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  • My bikes
    '07 Griso '01 V11 Sport '93 Daytona 4v '87 650 Lario Aprilia RXV550 Roadracer project
  • Location
    The skinny part of Maryland

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  • Interests
    Fast bikes and Loose women (except when my wife is around, then it is just Loose women.

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  1. Yeah, the PC925 is way too big. I had one in my Daytona, really it was too big for that as well. Not sure why Odyssey lists it for some Guzzi's. I suspect it fits in certain Guzzi's, perhaps the Cali.
  2. I am pretty sure there is nothing inside you can't guess by looking at the outside. I would bet if you rolled a golf ball down the pipe (or whatever size ball would fit) it would roll right through the crossover. If you held the crossover at the right angle it would go straight through. But if you held it at a different angle you could probably get the ball to fall out the other pipe. There is surely no baffling or anything else in that crossover. It is basically two pipes weld together so that they cross in an X pattern. The stock crossover is welded up of stamped steel and has a baffle of sorts in it. But this one looks to be made better and likely flows better.
  3. It is funny. Way back in the early 90's I used Lasertec 33's and liked them. They were a great front tire, even used them for light track duty. Then at some point they developed a bad reputation, deserved or not I don't know. I had stopped using them, not because of issues with them but because I was riding motorcycles that ran radials. When I started hearing bad things about them I was surprised.
  4. Racing was tons of fun, that was when we were kings..... While some exhaust systems are made more for looks and more to a price, in general I have learned that when you have people that know what they are doing you should let them do what they know works. I don't try to tell them how to do something I came to them to do. I do want to build an exhaust pipe for my Aprilia 550, I think that would be a fun experience. I would love to make a double exhaust pipe for it, two separate pipes one for each cylinder, with some sort of megaphones on the end leading into the mufflers. I always liked the look of the old XR750 Harley flat track bikes exhaust systems. But it would be hard to beat the look of the underseat exhaust it has stock.
  5. A few thoughts about this. First, many people think that a larger pipe will keep exhaust velocity up, but that is not how it works. If you were to compare two systems, one with a larger pipe diameter than the other but both close to the right size, the larger diameter pipe system would have lower exhaust gas velocity than the smaller pipe diameter system. There is a max size for exhaust pipe given your displacement and power levels. Anything above that slows exhaust gases down. Really trick systems will use a smaller diameter pipe right out the exhaust port and step up to larger diameter pipe 6 or 8 inches down the pipe. They are counting on the fact that the fuel / air mixture is still burning as the exhaust exits and as such it is still expanding. Because of that, the pipe diameter required for best exhaust flow is less right away by the exhaust port and increases further down the pipe as the air / fuel mixture finishes burning. But any sudden increase in pipe diameter / size will result in a slow down of the exhaust gases. Sadly, the stock exhaust crossover is just such a change in diameter / cross section. But the stock system is built to be cheap to manufacturer while working well enough. After market systems should be able to work better. But how much better can vary. Next, exhaust gases do no flow out the exhaust in a steady flow, they are pulses. Between the pulses there are waves of negative pressure that flow back up the pipe. Since the Guzzi V twin doesn't fire the two cylinders at the same time the pulses of exhaust from each cylinder are never trying to flow out the pipe at the same time. If the system works well, the negative pressure waves flowing back up the pipe from one cylinder will help the other cylinders positive pressure exhaust pulse exit quicker, which then can cause a stronger negative pressure wave to arrive at the exhaust port of that cylinder. The interaction between positive exhaust pulses and the negative pressure wave happens both between the two cylinders at the crossover and at the exhaust valve. But because a 90 degree V twin doesn't have an even firing interval between the two cylinders the affects of exhaust negative pressure waves are more likely to be back at the exhaust valve from that same cylinders exhaust pulse. But there are systems with complex crossovers, like the Ducati "spaghetti" system that have two separate crossovers to address the differences in timing between the two cylinders. All I can really say is back in the day I wanted a two into two system for our Ducati 750 twin racebikes (two separate exhaust pipes, basically). I did not think that a two into one system, or a two into one into two system, would work best on a 90 degree V twin. But we ended up having a system built by a guy who built exhaust art. And he didn't build what you told him, he built what he knew would work. We ended up with a two into one system. It maybe did not make the most peak power, that probably would have been from a two into two system, but it made more power under the curve and as such was ultimately faster than other bikes that claimed to make more peak power. Another really cool exhaust technology is merge collectors. If you want to learn more, google that. Merge collectors put a lot of effort into merging the different exhaust pipes into a single pipe while controlling and maintaining the size / cross section the whole way. They don't really have a lot of benefit for a 90 degree V twin like a Guzzi, but they are exhaust art.
  6. Well, a name is just a name. But I would call that an X Pipe. And generally X pipes work well. The stock Guzzi piece is a lower cost version that does not work as well. The stock Guzzi piece is just welded up out of stamped steel. That one has far more effort into it and should work better. The X pipe is supposed to be that narrow at the crossover. It should be the same diameter as the rest of the pipe. A sudden larger cross section in the exhaust results in the exhaust gases slowing down. When they slow down the loose energy. That should keep velocity up, which keeps energy up. I think it is a reasonably nice looking system An even more extreme exhaust style is a merge collector. For those they go to great lengths to keep cross section even and velocity up. But they take up too much room and you probably could not fit one on a Guzzi easily.
  7. I wonder if it was a titanium can wrapped in carbon fiber looking stuff or a steel can (maybe stainless). At that weight it would have to be some pretty thin steel I would think. The other option would be an aluminum can. That is a possibility. The wife's cans have a metal tag riveted on them saying "Not For Street Use".
  8. An H pipe is a different layout than an X pipe, an H pipe fails under the category of simply trying to share the exhaust between the two sides. It is more about making the exhaust quieter than it is about making power.
  9. I have not watched that video from them. But they are not a spoof and they do great work. They did a great segment on oil level, showing how too much oil not only costs horsepower but it also hurts oil pressure at higher rpm (the oil gets aerated by the crank and aerated oil will loose oil pressure). They are serious, and pretty smart.
  10. Hard to tell from the angle of the pic, but that looks more like an X pipe than a crossover. A picture of it from directly above should make the design clearer. There are different style crossovers. Some merge the two pipes together and then back apart as smoothly as possible (those are the ones I like). Other choices simply allow the two pipes to share exhaust duties. And some use the X pipe design, but the X pipe design is more common on old muscle cars (perhaps that would also work well on a Guzzi with its old fashioned design).
  11. That seems like it would not be legal. My Chevy Bolt electric car actually uses re-gen when slowing down and it will trigger the brake lights when doing so. But triggering the brake lights without hitting the brakes seems like it would be illegal. Also, what about every time you shift? Maybe you could install a secondary "brake light" that was G-force activated, when it senses the vehicle slowing down by G force it turns on.
  12. I suspect it will be used in all the future small block Guzzi's. That is why they made it, to comply with emissions regs. Give them time, it will become the small block motor. It is a step in the right direction, a better small block. But it is way short of where it should be. I am not very optimistic about a larger displacement performance engine from Guzzi. And that is too bad. It seems to me they could borrow some of the design work from Aprilia and create an amazing Guzzi motor. Imagine a sideways V4 in a Guzzi, or even a sideways V2 using the old 990 V2, using the cylinder and head design from the Aprilia motor but in a new crankcase that turns the engine sideways. I would have to buy one of those, in a sporty chassis. But alas, we get a warmed over small block.
  13. I have bought two pairs of those same mirrors on ebay ages ago. Even down to the blue tint of the mirror glass. One pair was on my Griso, the other pair was on my Daytona. Currently I needed / wanted mirrors on our bicycles, so I grabbed a pair and installed one each on each of our bicycles. Sadly, the Griso is laid up with clutch issues and doesn't need them, while the Daytona needs a new battery.
  14. I don't really come here for politics. But I gotta say; 1) Yeah, we are a democracy, and a constitutional republic. The two are not mutually exclusive. 2)This is not in any way an isolated case. 3) So often in this country justice does not prevail. Especially if you aren't white. 4) It may not be taught, but it is clearly practiced. 5) Sorry, but the media isn't to blame. Turning them off and ignoring this problem won't fix it.
  15. Different brand shocks have different adjuster wrench needs. Do you have the Ohlins shocks? If so, I would use the Ohlins shock wrench.
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