Yet another crossover question

[Yam350]

I apologise in advance if this has already been covered but..........I’ve been looking at crossovers and there’s loads of differing opinions as to which is best. I’m wondering if there is any gain to be made by de-gutting the original item or if indeed there is anything to remove which would give similar gains to the popular aftermarket options. My bike is a uk spec 2002 Lemans currently fitted with pro race cans, std airbox and filter, and power commander. TPS etc set up as per the excellent advice on here so it runs very well.

[Steve S]

There's not really anything inside the stock crossover to gut, I bought a Mistral item a few years ago but it didn't fit very well, I am running the stock item on my Nero with open Delkevic silencers and it goes well, aftermarket crossover will make more noise, btw my mate has bought an 05 Cafe Sport for £4k if this helps to value yours but thanks for the offer

[GuzziMoto]

Gutting exhaust components seldom does anything positive except increasing noise. People who have gutted the stock crossover, as I recall, reported increased noise. But that does not mean an increase in power, Odds are, gutting it will reduce power output.

From an exhaust flow perspective, the last thing you want is your exhaust flow to dump into a larger section of pipe for no reason. That typically causes a drop in velocity of the exhaust flow, that is not helping. You want to maintain exhaust velocity. You want the flow to be controlled, especially where two flows are merging together or apart. In this case we have both.

[68C]

You would have thought a V Twin motor with its uneven exhaust pulses would work better with no crossover, just down pipes into seperate silencers. The 1969 Triumph T120 Thruxton system had larger diameter down pipes which reduced in diameter about halfway down, cannot recall if it had a crossover - probably one very close to the exhaust ports of course that had even pulses.

[luhbo]

As said above. The stock part definitely is the best possible compromise. It fits precisely and it gives that distinctive soft, dark growl that most people expect from a Guzzi.

There are basically two types, Stucchi and Mistral. One is worse overall, the other one gives a remarkably improved top end. Please search the forum for details as I'm using none of them.

[gelos]

You can look on my dyno runs here
http://www.v11lemans.com/forums/index.php?showtopic=8556&page=12

My favorite is Stucchi, the stock part is not bad, Mistral no comment

[docc]

" . . . soft, dark growl . . . "

[brubache]

Well.. for what its worth.

Stucci is no longer made and prone to cracking. (edit... thats FBF not stucci)

Mistral fits exact and is quite decently made in my case.

The stock ones are cheap.  Seem to perform well enough.

 

There is literally almost nothing inside the stock unit.  There is a flat "baffle" of metal plate with holes in the middle mounted horizontally half way up.. kind of cutting the bottom and the top area in half.  

 

Can't say that the Mistral makes a tonne more noise than the stock.  But I would say its deeper sounding in a nice way.

 

Overall I have no complaints about mine.  

[czakky]

Stucchi x-overs crack? Don’t know I’ve ever heard of one cracking.... I’ve cracked an FBF x-over and a stock one (twice)

But the Stucchi is built like a tank.

[footgoose]

Stucchi x-overs crack? Don’t know I’ve ever heard of one cracking.... I’ve cracked an FBF x-over and a stock one (twice)

But the Stucchi is built like a tank.

 

I agree with this. Not seen a Mistral, but I have a Stucci and an FBF and the Stucci IS built very well.

[brubache]

Ill find that for you

[brubache]

Follow this thread perhaps.  Its covered crossovers before.  My error I believe.  It was the FBF one.

 

http://www.v11lemans.com/forums/index.php?showtopic=19379

[docc]

Greg Field ave us a good crossover thread *back in the day* 

http://www.v11lemans.com/forums/index.php?showtopic=11564&hl=mistral

[r3datom9]

Looks like there is a crossover for sale on CL right now if anyone is looking.  Looks like and FBF:

 

https://raleigh.craigslist.org/mpo/d/moto-guzzi-v11-performance/6416561999.html

[LowRyter]

Greg Field ave us a good crossover thread *back in the day* 

http://www.v11lemans.com/forums/index.php?showtopic=11564&hl=mistral

 

interesting read.  I had no idea that the crossover made such a difference, the Mistral boosting low end and Stuchi the top end.  

 

Seems that the POs of both my Guzzis (EV and Sport) installed after market crossovers.  I just assumed it was done because the factory POS cracked or maybe because of hesitation with the throttle.  I had no idea they were big performance enhancers nor that one affects power in a different range than another.  

 

With all the speculation about different cams, it looks like a crossover might be pretty important by comparison.