M900 Carbie X-Pipe Mod

[dlearl476]

Hey all, I'm fixing to ditch my RoadRacing exhaust and go back to a pair of Contis I bought a last year. My mechanic mentioned that it helps a lot to cut out the X section of the XPipe and replace it with two pipes.

A couple of months ago, I found an eBay ad for a guy in Las Vegas that does this, but now that I'm ready to pull the trigger on it I can't find the ad.

Anyone know this guy or someone else that can do this mod?

[Dirty Duc]

Lots of people can do this mod, but you aren't very specific.

What do you hope to gain? It's my understanding that the crossover is a significant bonus to rideability over two separate pipes, but the stock crossover can be improved a little by cutting out the stamped x and welding flat metal in its place.

Basically the same, iirc, as a full spaghetti system. All three of which (with the Conti's) will be better than the RR system.

All of the options merely moved a couple of torques around for relatively mild hp gains.

Ymmv, I'm just some dude on the internet.

[dlearl476]

Thanks, DD. Improved stock pipe is my goal.  And, in an uncharacteristic move for me, I actually did a screen shot of the eBay ad.




As you can see, the two pipes are still joined, just the big restriction at the joint has been eliminated. I'm going to see if some high-end muffler joints can do it locally, if not I'll send them off.

Nate, I dint know if this is kosher or not, but here's the guys contact info in case anyone else is interested in doing this.

[Dirty Duc]

It's easier to cut the stamped restriction and weld in flat metal with basically the same effect as that pictured. A full spaghetti system actually matches length on the two headers.

It might not look as cool, but it's under the bike where almost nobody will notice the difference anyway.

[dlearl476]

It's easier to cut the stamped restriction and weld in flat metal with basically the same effect as that pictured.

I was warned against that as basically it makes the two gas pulses collide with each other.

A full spaghetti system actually matches length on the two headers

Got a brand name, or a source? I would love to have equal length headers, as long as they'll work with cans in the stock (low) location to clear my panniers. Trouble is, these bikes are 20 years old now. Lots of stuff is NLA.

[Dirty Duc]

I was warned against that as basically it makes the two gas pulses collide with each other.

That's not my understanding of how exhaust pulses work. I don't have the details to hand, mostly because it's been a few years since I've done the math for the salt bikes. The internet has the knowledge if you beat your search engine into submission. I don't mean to be a jerk, just it's not one of the things I worry about. I remember the discussion somewhere on here, and the weld your own was basically the same as the fancy "need-a-jig" version you posted.

Got a brand name, or a source? I would love to have equal length headers, as long as they'll work with cans in the stock (low) location to clear my panniers. Trouble is, these bikes are 20 years old now. Lots of stuff is NLA.

Nope. I roll my own these days, but I'd consider myself far from pro. IIRC, Termi was the only "spaghetti header" and the money was dear. If you've got money to blow there are solutions... some of which used to be sponsors here.

My  friend had them.
You have to totally clean of content them to make them work and then they are loud.
His  W2 -98 w 39mm FCRs & pods, polished heads w DP cams & HC made 88 RWP, mine made 82 w V2 & 41mm, SS cams & HC on same dyno.
Still find it hard to believe that it made those numbers w those small valve heads, although I sen the chart dozens of times.
Some clearing issues, yes.

[dlearl476]

I'm sure for my riding skill and talent either would be fine. A mechanic I trust told me the "weld on square" version would likley require rejetting my FCRs but the replacement pipe would be plug and play. I'm not knowledgeable enough to know any different.

But I'll take that into advisement. I'm sure it would be a snap for any good muffler shop to cut the center and resell it. I'll see what the Internet brings. I wish I'd been looking all winter for a silmoto spaghetti header. I might have found one used by now.

[Dirty Duc]

My thoughts on a carbie with FCRs (there are others with experience)... the exhaust probably isn't the kicker for power. I don't know what other mods you have, but they work in concert.

The difference between what I suggested and what your mechanic suggested... I'm a fuel injection guy. But what I know from fuel injection tells me that if one of these solutions requires rejetting, so do all the others.

I'd call for koko64 or howie or speeddog or to answer any carbie-specific questions... but carbie questions here don't usually worry about exhaust parameters.

I think you are looking at where you are gaining a single (or less) hp depending on other mods. The quote from greenmonster shows a peak difference of 6 hp with different cams, different heads, and different carbs.

[Dirty Duc]

Also more info here:
http://www.ducatimonsterforum.org/index.php?topic=55255.90

[dlearl476]

Thx for the info DD. Truth be told, I'm old and slow and it probably doesn't make a bit if difference. It's just hard to break old nit-picking habits.

[koko64]

The stock pipes are surprisingly good. There is a link to a spaghetti Vs oem system and the bang for bung ain't worth it. The spaghetti system gains a couple of hp at the very peak but that's it. Throttle response may improve but I don't have FHE on that. I'll look for a link from Doug Lofgren. Maybe a racy system might help with other big mods. Stain tune once made a system with that type of enhanced crossover and larger diameter pipes. Maybe 45mm iirc. I lost the catalogue.

[koko64]

Can't paste the link.Look up Reed Herman's 944 report on Lofgrens site. The oem pipes seem to work well to about 90hp.

[Howie]

The big benefit from a spaghetti system on a Monster is road clearance.  At that, only if running rear sets.  Open the restriction?   As koko64 said, plus a lot more noise.

[greenmonster]

"It's easier to cut the stamped restriction and weld in flat metal with basically the same effect as that pictured."

I did that. Maybe a little more grunt at lower revs but not worth the trouble.
Rejetting not needed.

Vegas guy has any before/after Dyno charts?

[koko64]

My old Superlight had this mod of enhanced crossover, but only on one side for each cylinder pipe. So only two of the four sides of the star stamping where modified and on opposite sides with the radius of each pipe as it entered the star. The work appeared to be carefully aimed at not opening the crossover volume too much. My guess is there was concern about a loss of gas velocity at certain revs if there was too much volume at the junction.