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My supercharged K8 project...
The bike pictured above is my bone stock K8. A friend gave me a fantastic deal on this bike last year, and it has just under 2000 miles on the clock. I love this bike for the same reasons everyone does -- incredibly smooth, extremely capable and controllable, great power, and fantastic ergonomics for a supersport machine. The local Dynojet 250i says it puts down 152whp (SAE corrected), which is actually more power than a full-exhaust, PCIII-tuned '04 ZX-10R produced on the same dyno.
Now, normally the next step would be to add an exhaust, change the gearing around, or add some braided lines, and while I'll eventually get to those mods, I have something different in mind right now...
It's a Rotrex C15-60 supercharger, right off the plane from Denmark. This little unit can support over 230whp, and that's the number I'll be shooting for with my little project here. Also, the impeller wheel used to be cast, but these new wheels are apparently machined out of billet.
Before you ask, yes, I am a power junkie. There's just no going back once you've ridden a boosted literbike...
You can see how small it actually is compared to the bike. Somehow, some way, it will fit in there...
After staring at this sight for a couple of days, I realized the only place to put this thing is in-between the engine and the radiator, just below the frame. I'd love to stick it up higher, but the frame would get in the way of the belt (which is a dealbreaker) and the radiator fan would also have to be relocated. Placing it lower eliminates these problems, but makes it much harder to hide the drive behind the fairings and also places the inlet of the Rotrex very close to the header. I also do not want cornering clearance to be compromised at all, so it will be in as far (and up as high) as possible.
If anyone is wondering how I plan on driving this thing, take a look at the picture above. The M10 bolt currently fastened into the end of the crank will be removed and a machined adapter will take its place (this adapter has to locate perfectly off the crankshaft for this to work). A pulley will sit on top of this adapter and then drive the supercharger via an 8mm synchronous belt. The supercharger bracket will either take the place of the stock cast cover or locate off of it -- I'm not exactly sure yet which way to go.
There's a lot of work left to be done, but I'm looking forward to it. I plan on tuning the ECU directly and, of course, it will run on pump gas. In the meantime, wish me luck, and stay tuned...
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Alright, here's the deal -- I have a ton of updates to post, but no more image space left on my profile. Does a membership unlock more space? Anyway, the last pictures I was able upload are of the construction on my custom underbelly exhaust.
I plan on extending the lower fairings out, and I played around with a bunch of different exhaust designs before settling on a slash cut. I first made a mock-up out of cardboard, then tweaked the design in Autocad before finally taking the plunge into stainless. I cut all the bends on our bandsaw and machined an inlet piece for attaching to the stock header.
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A friend of mine builds nostalgia funny cars for a living, so he has all the metal fab tools (shears, brakes, rollers) at his place, not to mention his son is a rather good TIG welder. So, I loaded up my supplies and headed over there for a long day (or two) of fab work. I used .049" stainless sheet for the body, stainless perforated sheet for the core (which we rolled into a 2.5" tube), and a 2.5" mandrel bend on the outlet.
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The core was wrapped with long-strand stainless wool and was welded into place. Then, we popped the top on while simultaneously stuffing the box with Bristol Core muffler packing -- this step was not easy at all, but somehow we got everything in there.
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We cut the stainless pieces so exact that we were able to fusion weld (no filler) almost every seam on the box itself. I also added an O2 bung on the pipe. The completed unit weighs less than 6 lbs and should outlast the bike.
Once I figure out how to upload more pics, I'll have lots more to share. Things get very interesting...
I plan on extending the lower fairings out, and I played around with a bunch of different exhaust designs before settling on a slash cut. I first made a mock-up out of cardboard, then tweaked the design in Autocad before finally taking the plunge into stainless. I cut all the bends on our bandsaw and machined an inlet piece for attaching to the stock header.
A friend of mine builds nostalgia funny cars for a living, so he has all the metal fab tools (shears, brakes, rollers) at his place, not to mention his son is a rather good TIG welder. So, I loaded up my supplies and headed over there for a long day (or two) of fab work. I used .049" stainless sheet for the body, stainless perforated sheet for the core (which we rolled into a 2.5" tube), and a 2.5" mandrel bend on the outlet.
The core was wrapped with long-strand stainless wool and was welded into place. Then, we popped the top on while simultaneously stuffing the box with Bristol Core muffler packing -- this step was not easy at all, but somehow we got everything in there.
We cut the stainless pieces so exact that we were able to fusion weld (no filler) almost every seam on the box itself. I also added an O2 bung on the pipe. The completed unit weighs less than 6 lbs and should outlast the bike.
Once I figure out how to upload more pics, I'll have lots more to share. Things get very interesting...
I've been subscribed and following this project with great interest. It seems redundant even saying it but... outstanding work! :thumbup
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Sorry if this is a stupid question but I see you've installed a point on the exhaust for what looks to be a butterfly.... are you putting the SET valve back in??????
Sorry if this is a stupid question but I see you've installed a point on the exhaust for what looks to be a butterfly.... are you putting the SET valve back in??????
Maybe for another o2 sensor.I've been subscribed and following this project with great interest. It seems redundant even saying it but... outstanding work! :thumbup
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Sorry if this is a stupid question but I see you've installed a point on the exhaust for what looks to be a butterfly.... are you putting the SET valve back in??????
Here's a little guide on CNC machining parts. Most people probably think that all it takes to machine a billet part is a drawing and the push of a button. Ha, I wish. Unless you have access to some expensive CAM software and a 5-axis machine, it's nowhere near that easy.
First you create a drawing. In my case, a 2D drawing of the front and back of the part is required. Then, using those drawings, you create a program that the CNC mill runs on. With the software we have, this means manually creating toolpaths, figuring out cutting depths, and generating code for each individual tool to be used. For this supercharger bracket, a total of 4 programs (front, back, fixture, facing) will have to be created to get to the finished part.
We're not done yet. After ordering material, the blanks have to be cut to the proper length. Then, each blank is squared up and faced (front and back) to the final thickness. The first op is the front side...
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Before the back can be machined, the fixture has to be created. This fixture locates the blanks via 3 pinned locations and will allow the final part to be cut out of the larger material.
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The fixture is clamped in the vises and the blank is bolted to it. After loading up a different set of tools, the backside program is run...
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The part is then unbolted from the fixture, cleaned off, deburred, and voilà:
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The only thing to check now is fitment on the bike. Think it fits?
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Woohoo! All is good. The only thing left to do now is send out the bracket and idler pulley for anodize.
http://www.youtube.com/watch?feature=player_detailpage&v=uFcQPXlDAdw#t=3297s
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