Large Crossover H Pipes

[Groover]

Has anyone every cut one of these open? Are there plate/baffles inside, or is it just an expansion space?

[Sheepdog]

I’ve heard conflicting reports about the location of the catalytic converters, but I’m guessing they are in the mufflers. The crossover would be an expansion chamber for pre-silencing and to promote equal exhaust flow. The Lamda sensor is on the crossover, so I’m guessing it is mostly empty as it the place for measuring exhaust O2.

[MattP]

there is was no baffels in mine when I cut a notch in mine and welded a bent picse of stainless steel sheet metal so I could axcess the drain plug. Wide open in side with some kind of glass mat held to the in side wall with some expanded metal stainless I think. The inside is wide open and probbly is a expanson chamber. You will gain no power replacing wiyh a H pipe.                                          however there are beleavers who spell better and will say other wise. But the easter bunny dos not exist, no matter what you think.  Matt

[Ncdan]

I’m not sure what it’s function actually is but I know that when I removed it from my CalVin it sounded absolutely great!!! Kind of reminded me of a 327 Chevy motor.

[Groover]

Thanks for the replies. I've "heard" that removing it (as in replacing it with the tube H type), you lose some torque. Not sure if it true or not, which is why I'm wondering what's inside. I'll have to try the comparison some day. My Le Mans 4's have that type, so not sure I want to get away from it if it costs low end torque. Thanks again.

[Ncdan]

Thanks for the replies. I've "heard" that removing it (as in replacing it with the tube H type), you lose some torque. Not sure if it true or not, which is why I'm wondering what's inside. I'll have to try the comparison some day. My Le Mans 4's have that type, so not sure I want to get away from it if it costs low end torque. Thanks again.

Keep in mind that if you remove it and replace with a H/pipe you may need to make an adjustment in your computer, some if the guys here can help on that issue.

[Groover]

It's a carbed engine, but probably still some jetting or other adjustments needed. Also, no 02 sensors on mine either for that same reason.

[Mr Revhead]

I replaced it with the H pipe on my 03 EV. Only thing I noticed was improved sound.

[Ncdan]

It's a carbed engine, but probably still some jetting or other adjustments needed. Also, no 02 sensors on mine either for that same reason.

Sorry Groover, I should not have assumed it was a later model guzzi. I doubt if rejetting the carbs would be necessary however some of the guys here would be able to offer more correct info on the subject.

[Bisbee]

I replaced mine with an H years ago on my 98 EV. Still have the original but am not going to cut into it since it is now unobtanium and very valuable . The bike immediately felt as if it could eat VFRs for breakfast. Hah! Years ago, in Car and Driver , a tuner was asked about this stuff. He said that well heeled clients would bring their cars in for more power and he found that a new steering wheel was worth 5 hp and a better sounding exhaust was good for 10 hp. It was all mental. But that’s not a bad thing if the owner is all smiles and his buddies are green and licking their chops.

[Guzzidad]

    I cut one open from my 1100 Sport. To my surprise there was nothing in there. I had read that it helps make power and I wanted to see why. I welded it back up and still have it. I wanted to replace it with a H-pipe but I waited too long. They cost too much now. They used to cost around $135.00 but now they cost something like $350.

[wirespokes]

I had an H pipe (a friend gave it to me after he sold the goose, having never installed it) and put it on the 85LM. I think it was for a Cali that didn't have as much upsweep to the mufflers, so had to adjust it a little. There's no shortage of low end torque.

It's just a cross-over joining the left and right sides. Since both sides don't fire at the same time, one exhaust pulse has two mufflers to exit through. Less back pressure. At higher RPMs there's probably not enough time for a pulse to cross over to the other side, so doesn't make as much difference. Race bikes tend not to have the cross over probably because they're running at higher revs most of the time. I removed the crossover on an R11S and didn't notice any difference, except a more pronounced exhaust note. But I'm sure on a dyno the loss of low end torque would be noticed - I didn't push it hard enough to be able to tell.

[Groover]

Ok, thanks guys. Starting to make sense. Maybe they started using the fatter ones for the larger compression engines to absorb more backpressure? So having that crossover, and exaust pipes with reverse cones might be overkill? Guessing if reverse cones were in place, then there would be no need for a crossover? Not that I have pipes with reverse cones, but have been tinkering in my head of using some.