Opening stock cross over

[senior rider]

I recently purchased a 2000 V11 Sport, and joined your very informative forum. I will soon be doing something about the ECU thing, flat spot between 4 and 5000 RPM.

 

 

My question is, has anyone opened up a stock cross over to see what the restriction is? I'm a retired

welder, and I'm comfortable modifying ex pipes. A picture would be really nice.

 

Thanks

Jim

[dlaing]

Somewhere on the forum there are pictures.

There is not much restriction in the crossovers.

The loss of mid-range appears to be some other design issue, like not enough restriction and maybe too much expansion and vagueness to the flow.

If you could create an X style crossover within the crossover box, it might flow better.

You could even perforate the tubes of the internal crossover and fill the box with steel wool, so that you get the power of the Stucchi crossover, but quieter.

[Guest rosso mandello]

I had mine opened, I expected to find a lot of restrictive material, I could remove, but there was nothing. The only thing is the bottom and the top, it has an extra metal plate welded onto it (holeplate)

 

I did not find, what I was looking for.

mogens.

[Skeeve]

My question is, has anyone opened up a stock cross over to see what the restriction is? I'm a retired

welder, and I'm comfortable modifying ex pipes. A picture would be really nice.

 

The restriction is too much volume, so that the exhaust gases expand, cool down, increase density, & lose velocity. That's why the aftermarket x-overs work better, even tho' there's minimal actual crossover to some of the designs. The correct diameter of the x-over tube would be 2^1/3 [that's the cube root of 2] times the diameter of the head pipes or muffler pipes [they're the same size], which amounts to a very minimal increase in size; the stock x-over isn't so much a crossover as it is a pre-muffler [which is why in one of my early posts to v11LM I incorrectly surmised that this was where the catalytic converter was hidden... NOT! ]

 

Best approach to modding the stock x-over would be to open, clean out the innards ['cause otherwise all that carbon contaminating the welds to the stainless will cause it to fail in short order] and weld in some finely perforated plates from top to bottom on the rt & lt sides of the box to maintain greater straight thru flow from rt header to rt muffler & vice versa. I hope that description is clear enough!

 

Alternatively, you can use the stocker to make a nice jig, so that you can duplicate the design of the Stucchi x-over w/o [hopefully!] running into fit-up problems once you're done... That may be, in fact, the best use for the stocker, since you'd almost certainly end up losing some weight by going to a less complicated piece a la' Stucchi's x-over.

[JoeV11]

I wonder if using a stucci cross-over with stock mufflers would increase performance any, or at least clean up that midrange flat spot? I don't want to make my bike too loud, but a little louder is good. I might have to buy one to find out. Joe

[Guest ratchethack]

I wonder if using a stucci cross-over with stock mufflers would increase performance any, or at least clean up that midrange flat spot? I don't want to make my bike too loud, but a little louder is good. I might have to buy one to find out. Joe

Joe, I ran my 2000 Sport for a year with a Stucchi crossover and stock mufflers before installing FBF oval carbons. The Stucchi made an instant improvement over the stock crossover in "seat-o'-the pants" midrange around the 4500 RPM "dip", and added a "rounder", slightly louder sound to the exhaust note. It was enough of an improvement to consider it an unqualified success in achieving wot I was after -- a flatter torque curve in the middle/low end of the range I most often call upon for torque. When I finally installed the FBF's, it opened it up & smoothed it out a tad more.

[Guest h8chains]

Please confirm this statement!

 

The Stucchi or Mistral cross over is effective only for the 2002 and older models since the 03 and on have the front crossover which is an improvement from the older setup.

[JoeV11]

I got my bike back last weekend and I must say the Stucci crossover with the rest of the stock exhaust (with front x-over) makes the bike so much better!!!! In fact, Greg at Marsh Motors says it's the best running stock V11 he has ridden! It really made a big difference in evening out the torque curve. I had them do the 1000 mi service that included valve adjustment and checking the TPS sync at the same time. All I can say is it's like a different bike! The sound of the exhaust isn't really louder, just has more bass, especially when decelerating. It sounds like a bigger bike, or maybe less like a smaller bike. Joe

[v11cafe]

Please confirm this statement!

 

The Stucchi or Mistral cross over is effective only for the 2002 and older models since the 03 and on have the front crossover which is an improvement from the older setup.

 

 

How about 2003 v11? Stucchi looks cool but what happens with the Lamda sensor?

[WitchCityBallabio]

How about 2003 v11? Stucchi looks cool but what happens with the Lamda sensor?

 

 

I wonder about that too with the 2004 Billybob. Does the ECU require and/or control tune in accordance with the Lambda? Will just changing over to a Stucchi with the stock exhaust require using a PCIII?

 

Thanks,

 

Doug

[Tom M]

I wonder about that too with the 2004 Billybob. Does the ECU require and/or control tune in accordance with the Lambda? Will just changing over to a Stucchi with the stock exhaust require using a PCIII?

 

Thanks,

 

Doug

 

Hi Doug,

The USA V11's don't have a lambda sensor so no worries there. If you just do the stucchi crossover you probably won't need to change your fuel map, but if you add freer flowing exhaust cans later you will probably need to address it with a PC3 or something similar.

[WitchCityBallabio]

Great. Thanks for the info Tom!