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neduro 01-20-2008 07:36 AM

KTM LC8 Exhaust and Auxillary Tank
This isn't technically a business yet, but since I'm considering it, I thought I'd start a Vendor thread about it.

I want more fuel capacity for both my 950 SE and Adventure, and after lots of poking around, the preferred alternative I can see is making a 2 into 1 exhaust, and replacing the other exhaust with a fuel tank. Both the Adventure and SE are already a bit front heavy (the Adventure much more so than SE) which rules out a bigger front tank.

The design parameters for the rear tank would be that it had to work with all common luggage racks and passenger pegs, it has to provide at least 2 additional gallons, it has to weigh less than stock when empty (including the exhaust on the other side) and it can't sacrifice power.

I believe that one tank shape can be made to work on both SE and Adventure (and presumably SM, although that's pure speculation for the moment on my part), with different 2->1's required for each application.

Here's a post about the project from Orange Crush:


Originally Posted by neduro
I'm embarking on the project many of us have thought about: building a 2 -> 1 exhaust, for the specific purpose of creating an empty space for more fuel capacity.

Ultimately, this post may turn into :spam because making one may not be much less expensive than making a bunch, in which case I'd start a business to sell them... but since I haven't made any sort of decision yet, it's not spam yet. :deal :D

In anticipation of questions about that, I started a vendor thread here so that we don't junk this thread up.

I'm lucky to have both an Adventure and Superenduro right now. I'm starting my work on the SE because it was already in pieces, but these same concepts will work on either variety.


First step was chopping up a stock "H" pipe to turn it into a 2 into 1.

Here's the finished product:

I believe that it will be necessary to make a larger diameter pipe past the junction, but I have dyno time reserved this week to find out for sure. I'll be testing the bike full stock, with 2 neptunes (baffles in and out), and with 1 neptune. I won't have time to change jetting between pulls, but I suspect we'll learn something anyway...


Then, I took some styrofoam and mocked up a tank shape.

Used packing tape to attach mounting points:

Glassed the top in to make it a bit more durable:

And presto-wallah, a reartank prototype for the SE:

Ultimately, the shape needs a little tuning, but it is ergonomically excellent (no edges to catch, impossible to feel when on the bike), is out of the way as the swingarm travels, improves the balance of the bike front to back, and will give over 2 additional gallons. Because of the length, I believe that the finished product should be filled with baffling foam to avoid a back to front slosh (or vice versa) under braking.

I've been kicking around constructions for the tank with a bunch of folks over the last few weeks, and it's been an interesting learning experience. The two methods that seem most practical are forming aluminum, and rotomolding.

The advantage of the aluminum option is that the cost for the first might be lower, but I anticipate that it would be easy to dent in a fall, and I worry about the effects of vibration on aluminum over the long haul.

Rotomolding costs a lot to make the first one... but I'm meeting with a vendor this week to find out just how bad the damages would be.

Anyway, I'll report the facts here. I think this will be an interesting one to play out!

If you're interested in this project, please let me know. If the response is strong, I'd be more willing to invest in a way to produce these for a reasonable cost (ie, take the risk on buying a mold).

The Fist 01-20-2008 08:57 AM

Hell yes Im interested.

Dirt2007 01-20-2008 02:04 PM

I would be interested. What are you thinking on getting the fuel to the engine?

neduro 01-20-2008 04:21 PM


Originally Posted by Dirt2007
I would be interested. What are you thinking on getting the fuel to the engine?

Both SE's and ADV's have a low pressure line that runs between tank lobes, with a petcock on both ends. I will T into that line.

wsdbikes 01-20-2008 04:56 PM

i'd be interested in this also. I fabbed up a prototype 2-1 for my SM that worked ok. need a custom mid-pipe for it though and the Yosh can i used was too loud for my.
the extra tank capacity would be great though if it is realistically priced. One tank design could work for SE ADV and SM with bracketry for each if necessary.
really good idea though. keep us posted

allengt 01-20-2008 10:07 PM

Interested, Yes
Sounds like you have the correct design criteria. I would hope that it would not be too loud. I would still like to be a semi-nice neighbor! :D Let us know when you have a rough estimate of the cost.

Max Kool 01-21-2008 12:20 AM

You are doing a great job! we are doing sort of the same for the Xchallenge.

Keep up the good work!

HappyGoLucky 01-21-2008 02:50 AM

I have run the costs for a roto mould down here in SAfrica, where it would be cheaper to make the mould and then run it and make tanks, than in America.

If youre interested, I have all the people researched who would make it a proper venture.

I decided against doing it, rather concentrating on other businesses. But to give you an idea, to tool the mould will cost about R80000, which works to be about $11500 odd.


tn-steve 01-21-2008 12:47 PM

I'm interested - 950 Adventure.

PackMule 01-21-2008 01:09 PM


Originally Posted by HappyGoLucky
I decided against doing it, rather concentrating on other businesses. But to give you an idea, to tool the mould will cost about R80000, which works to be about $11500 odd.


Holy f*ck!


Meathead 01-28-2008 05:07 AM


neduro 02-17-2008 08:58 AM

I finally got a chance to check the 2->1 shown above on a dyno. To do it, I had to venture into the heart of darkness...

Very nice folks, actually! We decided I should swap my worn 908 for a scorpion for the dyno, they came out to watch me change the tire and were bug-eyed when I pulled off a sub 10 minute swap in the cold. I got a private chuckle out of that, not sure how often they see that from their dentist crowd...

Into the war room:

Pull the pin and stand back:

I tested the bike 3 ways. Everything else, jetting, tire pressure, etc, remained the same otherwise.

1) 2 into 1, neptune exhaust, baffle out.
2) 2 into 1, neptune exhaust, baffle in.
3) 2 into 2, neptune exhausts, baffles in.

I would have liked to test more variations, but this ain't free.

Pictures speak louder than words:

The answer is a resounding hell-yeah. Peak horsepower was made with the 2 into 1 installed, baffle out, and the 2 into 2 and 2 into 1 with baffle(s) in were within 6/10ths of a hp peak.

There are some additional changes in character that are more important, in my opinion.

First, the 2 into 1 options seemed to perform better below 5k RPM, with somewhere between 1 and 4 more pound feet of torque. From the saddle, this feels apparent, with a smoother bottom than stock, somewhere that is commonly useful.

Second, the 2 into 2 option really only has an advantage from about 5 to 7k RPM, where it in turn makes 1-4 more lb/ft. This is the "hit" that is apparent from the saddle on the stock bike, which is considerably smoothed by the 2 into 1, not only because of the minor loss in this area but also because it's stronger below, so the gains present are less apparent.

On pavement, the 5k hit is fun to "surf", but in the dirt, IMO, the more linear the power the better, as it makes it easier to retain connection with the rear tire. The bike still has plenty of go at these revs, to sacrifice a few pound feet up here in exchange for a smooth characteristic is a worthy tradeoff, again IMO. :D

On top (7k up), there isn't much between them. Baffled vs. baffled, they are very close. Unbaffled 2 into 1 beats them both, and I suspect unbaffled 2 into 2 would equal or beat that. Anyway, I don't ride there much, so that it's within a few is all that's important to me.

Jetting was as we ran it in Baja (too rich) and was not changed between the 3 pulls.

So, the power of this system is arguably better than stock, depending on what you're looking for, but the biggest advantage to me is the weight loss. Stock cans weigh 11 lbs EACH, up high, and as far from center of mass as possible. Aftermarket cans vary between about 5 lbs and about 9 lbs. A 2 into 1 system loses that weight instantly, as well as freeing space for a tank, a map tube, whatever.

I was impressed enough with this outcome to think there's a product here, hence my posting in Vendors. I spoke to some buddies that run a racecar shop, and they turned me on to a fabricator who can produce these. I sent him the prototype, and finally got a quote back for a low production volume, which I need to decide whether to give the go ahead on.

The offering would be a 2 into 1 that looks exactly like this:


This will fit any muffler that bolts to the stock "H" pipe, including stock of course. It will use all stock mounting points.

The piece for sale would not made from pieces of a stocker, obviously.

Instead of the crappy chroming of stock, this would be jet-hot coated, which will never blue, is easy to clean, promotes good flow characteristics, and so forth. The price would be $225 shipped in the US.

Some changes will have to be made to fit an adventure, I haven't tested these yet but they would be on top of my list to do. There would be an offering for both SE and ADV owners in any case. The SM is different, so no love there.

If you're interested and/or have questions, please let me know either with a post here, or a PM, or an email from my profile. I intend to make a decision fairly quickly, and once I do, the pieces would be 6-8 weeks out, so still in time for riding season.


gweaver 02-17-2008 01:45 PM

Not trying to hijack, but what single can exhaust would you recommend? I'm running stockers, but plan to upgrade soon. If I hold out for your 2-1 mod, is there a single sided exhaust that fits (from some other bike), or would I have to buy a 950 aftermarket exhaust and just use one side? Does that make sense?


neduro 02-17-2008 02:03 PM


Originally Posted by gweaver
Not trying to hijack, but what single can exhaust would you recommend? I'm running stockers, but plan to upgrade soon. If I hold out for your 2-1 mod, is there a single sided exhaust that fits (from some other bike), or would I have to buy a 950 aftermarket exhaust and just use one side? Does that make sense?


Makes sense- it's something I need to investigate.

One idea is that I think all exhausts that mount with a strap (vs an integrated mount) could be used on either side, so if your buddy has Akros or something along those lines, you can buy one from him if you both go 2 - 1.

It's my intention to investigate buying single cans from a vendor, but I haven't done it yet.


cjracer 02-17-2008 04:29 PM

Great info Ned. You've done a great job w/ this.:thumb I like the idea of running a single pipe now that you have proof that there is very little power loss across the board. I'd like to make a tube to hold tube/tire repair stuff or whatever seeing as how I have the Aqualine tanks for larger range. I'd be interested in a 2-1 pipe for the Adv.

Keep up the good work. :clap

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