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Custom Jardine GP-1 RC8 Exhaust

17K views 22 replies 11 participants last post by  SlowMo 
#1 ·
So I bought an extra stock exhaust off of ebay a few weeks ago (7000 miles on it, no dents or scrapes, $50 shipped!) with the intentions of gutting the canister of the baffle and CATS and welding it back up. Well there are now more welds inside of these than there once was (at the time of the DeCat/Tuneboy post on UK KTM Forums) so to fully get it apart it takes 5 cutoff discs and way too many ugly cuts. If I was to weld it back up I would have a giant heavy shoe box with who knows what for sound and performance so I trashed the canister but kept the link pipe. My plan is to cap the rear cylinder outlet on the link pipe and with a few elbows mate it to a Jardine GP-1 exhaust (that I just bought new on ebay for $220 shipped). Hope to have this welded up and installed in the next 2 weeks before I ride out to Ocean City Maryland's bike week. I'll post a few pics in case it is of interest to any other poor RC8 owners out there :p

 
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#5 ·
This is why I wish I had fab skills. I never used to work on my own stuff, then I joined the army and now work on Blackhawk helicopters. I realized I do have some mechanical skills and of taught usually learn things 1st time go.

SOMEONE TEACH ME HOW TO WELD!!! Lol


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#6 ·
Nice innovation. Tell me, what is the point of gutting the baffles ? I have a'12 RC8r wouldn't mind trying something similar I you don't mind me stealing the idea. I too am a boller on a budget.

Anyone thought about somehow customizing organ pipes to flow under rear seat like an MV Agusta? Always thought that looked good. Not for an RC8? What are the Pro's and Con's of just extending pipes not using an actual muffler?
As you can tell I know very little about exhaust systems. Can you guys enlighten me.


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#7 ·
I am sure anything can be done where there is a will there is a way.
I my self have no talant in this art.Welding is something I wish i knew I have plenty of ideas ,The problem with pipes under the seat I see is it would have a ton of twists and turns
If you could do it like the 990 duke that would be cool I just think flow would be a problem and how do you mount it. the beauty of the RC8 is that it looks so clean.And of course performance some thing like that would have to be made on a dyno a piece at a time.

I used to watch Donnie E at FMF make pipes add an inch and run it, turn it here and run it.It was amazing how they did it back then. Now I am sure now computers do the work.
I am sure the reason the RC8 has it pipe the way it does is for a reason.
Now Wolf has an interesting set up and I am lookung forward to seeing it up close. It is made by a company that make pipes for many superbikes His pipe is very differant than any other MFG.

I don't think you could do it like the MV but if they did and it worked.
That would be something to see.
I use the FMF system because i have used them for many of my bikes for over 20 years starting with dirt. Now they are a leader in four stokes.I like the way mine works and is half the price of an akra if not more.One thing you can do with the akra is have the whole system headers and can. not cheap 4k
and it has it's own map like the FMF.I just don't think the performance gains are that much more for the extra cost.

Now if I was a pro racer and some one else was paying the bills The Akra would be a no brainer. They make a great product.
 
#8 ·
Jkasal, the point of removing the baffle within the exhaust is to get more sound. It is there to cap the sound at a certain decibel that satisfies some government imposed regulation. Nobody I have ever known have found it to be enforced, I must pass 5 Harleys everyday on my way home from work that have straight pipes and are louder than a fire truck.

Removing the 2 cats (catalytic converters, another government mandated component that no one cares about) is to gain higher flow. Higher flow on the exhaust end paired with higher flow on the intake end (something other than the paper filter that comes from KTM) should increase power a little bit, a good bit more if the pair are tuned with a proper ECU fueling map.
 
#9 ·
Good info, thanks guys for the input. Very helpful. What would be a main concern if I too was to convert a Two brothers or Jardin exhaust for my RC8 (Doesn't have to be those two specifically) as long as I re map engine ? Also,what would I use to Map the engine if I used a foreign exhaust that I "rigged"? Can I Auto Tune my bike and adjust performance to my specifications? What would you guys recommend ?


Obviously this would be a short term deal and as soon as more money grows from my backyard trees I will get a "real" exhaust system.


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#10 ·
The thing that sucks is for power you wanna try to keep header length equal, bends to a minimum and run both header pipes into a collector before the muffler. There's just not much room there.
I was thinking, run the front header pipe down and as far left on the bike as possible with a 90* turn toward the right side of the bike about mid point under the engine.
Run the rear header pipe down and as far left as possible, bring it forward with a 90*turn toward the right side of the bike at the midpoint right next to or above the front header pipe.

Now both header pipes are under the engine pointing toward the right side of the bike with equal length.
Use a 90* elbow large enough to go over both header pipes. Tack the pipes in place and beat/form the 90* elbow to the header and weld it up.
Now you have a header system that puts your collector at the mid point under the engine and pointing toward the rear of the bike. Find the shortest slip on you can and I think it'll be right at the exhaust cutout.

Lol I hope somebody can follow that. I don't have autocad on my phone.
 
#11 ·
Sounds like it would work. Any reason you absolutely need a slip on? Could you just have a longer collector that's ends at the cut out ? What is the main purpose of a slip on? Just to control sound?

Keep em coming guys I'm actually learning something. Thanks again.


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#12 ·
Yes, I have a full akra system on my bike and its kinda loud to be honest. Dont get me wrong im no old man I love some good noise but the thump just beats inside my helmet. That being said I wouldnt give that sound up for anything lol.
I have ran my bike without the muffler just the header and collector and holy **** man it is dumb loud lol. It sounds mean as hell tho.
Also a slipon should add a little backpressure, not a whole lot but a little. A little backpressure should help your torque numbers and shouldn't take much off your hp on the top end.
 
#14 ·
I can't wait to see what you come up with.
I weld and fab for a living but I don't have access to a proper tubing bender. I wish I did I would be turning out rc8 exhausts like crazy, im bored as hell with this broken leg lol
 
#16 ·
Been so busy, here is a quick update.

So again, I decided to call off my plans of decating and removing the baffles from the stock exhaust once I realized I would have to add 10 pounds of weld just to get it back together. This thing is SOOO heavy, even if I did get it back together it would be a giant steel shoebox with who knows what for sound and performance so I scrapped that plan.

Here is a pic of the stock exhaust with most brackets cut off.


I split the first enclosure open...


Which revealed the second enclosure now has welds running horizontally along the 2 internal ribs/walls that the baffles and cats run through. If I had more time I would note all these photos up but if you look at the UK thread pics and compare them to mine you will see this wouldn't open up without 10 more feet of cuts.


So I chopped the balance pipe off and reattached it. Oddly enough one of the previous mounting holes works great for the Jardine GP-1 exhaust bracket. Same bolt and everything.


Bought a random piece of 2" diameter mandrel bent stainless that I will cut, rotate and weld to extend the balance pipe to meet the new canister.



Should look pretty decent, will need to cut the lower fairing by a hair :x Otherwise the tail end of it will surely melt from resting on the pipe.


Finalllly figured out my rear turn signals (have a board with a few transistors to take the weird 8.6V as a signal and use 12V from the battery to power some LED strips). Will cover that hole back up with a machined piece of carbon fiber which I will be sure to offer on my KTMCarbon site shortly.

Wish I could outline more, if there are questions let me know and ill make time to explain.
 
#17 ·
Looks great and should save a lot of weight.

I had 12volts to my led strips. If your using the stock front turns all you have to do for the rear is run one of the wires directly to the battery. I can't remember if it was the + or - wire that has the flash circuit on it. Find the wire with the flash circuit by turning on your blinkers and use a multi meter set to volts. You find the flash circuit and use that wire send the other wire - or + to the battery. It took me a lil bit to find the right combo of wires, I wish my bike was here I could go look at it and draw up a diagram. For some reason I think they were purple lol. If you go in with a meter it shouldn't be too hard once you find them the leds will be super bright
 
#22 ·
I bought a dominater slipon 600 shipped ,the can was sh*& and the pipe did not line up at all so I shelved it for a while ,I had already bought a stock can off ebay for 80 bucks to cut and see what was up with it.and shelved that. Then it hit me . I built a simple jig with the extra header pipes and then cut off the stock flanges off the donor can and cut off the flanges from the ill fitting dominator pipe and with the header pipes mounted on the jig I was able to reweld the flanges to a perfect fit back on the slipon pipe. I then found a jardine 12" gp can on ebay 68 bucks shipped brand new .I then welded a new section of pipe that fit the jardine can and a couple of washers to hold the retention springs ,once alll was fitted and finished I then heat wrapped the pipes and added a tail pipe extension to the can . remapped to the akra map .sounds evil run like hell
 

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