I saw a 'Mythbusters' type show recently that showed electric superchargers do nothing.

The impeller can move the necessary volumes of air, but it simply can't compress it to high enough psi to be effective.

 

My youngest son just graduated in May as an M.E.
His team did a structural analysis of moped frames,testing one to failure.(that's why they picked mopeds)They also modeled the frame in solid works,analyzed the flex points with little testing tabs that change ohms resistance with flexure. They studied the vibration and modified a frame with a top tube that helped strengthen the frames weak points. They got an A so to speak,the judges were impressed with they're testing and data. I had put forth the idea of an invention. The problem with that type of senior project is if your prototype doesn't work as well as intended, it reflects poorly.
good luck
marc

 

Well this is the problem, if you go buy an electric supercharger it is plastic. If you can go find half of a turbo casing with the propeller, find a way to really charge that bad boy up, you can compress the air no problem. Air compressors you have in your garage run off of electricity. It's all about efficiency and quality of the materials.

 

Apples and oranges. The air compressor in your garage is a piston design, not impeller. It also relies on a tank which it fills slowly to release psi quickly in short bursts.

 

Nice that you want to do something with the KLX - but I think you're going to find that because the basic KLX design has been around for so long that a lot of the low hanging fruit has already been picked.

I guess the suggestions are going to be very dependent on how ambitious you plan to be. If you're liking the idea of a centre stand then, no disrespect intended, it doesn't sound like you're intending to be too ambitious. So the ideas around ram air/turbocharging/supercharging are just too far out and definitely in the too-hard basket IMO. Besides, there are already quite a few ways to get extra power out of the engine (cam changes, big bore, pumper carbs, etc) and there is a point where extra power become far less important than better traction.

With the ideas around a frame redesign aren't bad, and a LOT of weight could be saved on the KLX with a lighter frame - but I would think you'd be better off figuring out how to fit make a KX-KLX hybrid that takes advantage of the alloy frame of the KX. You're also going to run into registration concerns when you do something as fundamental as change the frame.

If it were my project I would be focused on what I feel is one of the most neglected parts, and the parts in most desperate need of some attention - the suspension. I would be looking at:

• Triple clamps to fit 48mm forks - being able to fit Showa Twin Chamber or KYB 48mm forks off an early to mid 2000's model Honda, Suzuki, Kawasaki, or Yamaha motocrosser that have far superior performance and tuning options available to them than our humble KLX KYB forks. You can get relatively cheap second hand bikes on eBay that would be good to rob the forks from. Whether your project is focused on modifying the triple clamps off of one of the above mentioned bikes, or machining new clamps from scratch would be up to you, but I would be looking to try and keep the current ergo's of the KLX as they work well - so try keep the rake angle the same.
• Linkage/tie-rods modifications to fit a superior shock off another bike - similar to my above suggestion of forks off a bigger motocrosser, if you could figure out a way of retrofitting a shock off the bigger MX machines to fit the KLX without changing the overall ergo's of the KLX too much you'd be onto a good thing. Given the mounting point for the top of the shock is pretty much set so cannot be changed much without significant frame modification, your focus would probably be on the linkage assembly. To fit a different length shock while keeping the rear end behaviour the same or similar to what it is now (which is tried and tested) I would think you're going to need to design and machine a different linkage assembly and tie-rods to keep the bike height about the same.
• Vibration/shock absorbing handlebar mounts - quite a few people don't like the vibrations that come through the bars and have looked into all sorts of ways of damping it. I would be looking to the KTM PHDS (Progressive Handlebar Damping System?) mounts and Flexx handlebars for some inspiration here. You don't really want to simply replicate what they've done, but you can probably get some good idea's from them.

Another idea you might want to consider it re-designing the airbox and side panels to make changing the air filter quicker and easier - KTM and Husaberg are 2 bikes I've seen that have made this a LOT easier which just makes one wonder why all manufacturers haven't made it that easy. You might need to look at a defferent model filter the the KLX one to do this though.

If you're feeling nice and ambitious I would also advocate looking at making a simple auto clutch solution. I'm thinking something like the Rekluse EXP 2.0 ring (or Dynaring, that were put out of business by Rekluse for infringing on their patents) which just requires removing a couple of friction and drive plates to fit the ring, then installing a modified throw-out. I know you can get an auto-clutch solution for the KLX (from EFM?), but it requires removing the clutch assembly to send in for modification which leaves your bike out of commission while that gets done. If you could figure out a way of even using an existing Rekluse EXP ring in the KLX clutch that would be great.

If I had the time, knowledge, facilities, and inclination those are the things I would look to do. Will be interesting to see what you decide on.

 

Speaking of compressed air





But alas, it's already been done?

 

I was also thinking about those two points.
The lowest point of the klx is the rear shock linkage, if you could design a better one there would be some more ground clearance.
The autoclutch from EFM doesn't keep the clutch lever functionnal and does make the engine wider so there's room for improvement.

Good luck with your project.

 

You are absolutely correct. That is why something needs to be "Engineered" to work.

I have seen half of a turbo connected to an electric motor and produce boost.

 

Even better, he can design a supercharger that uses a piston :P It will be revolutionary! It can even transfer to cars, instead of a blown v8 we'll call it a v8+1

 

The problem is not that an electric motor can't drive a supercharger. The problem is that an electric supercharger is not feasible in a mobile application, especially a motorcycle. And even in a stationary application, I can't think of a situation where it would be justifiable, simply on the basis of inefficiency.

Here's a partial list of why:

An electric motor powerful enough to drive said supercharger would be a beastly thing to add to a motorcycle.

To drive said electric motor, you need to first supply electricity. The electrical system on the KLX definitely is not up to par. You would need something around half a horsepower or 373 watts of power to just supply enough air for 3 psi of boost to a 250cc motor at 6000 RPM. More like 0.75 horsepower at 10,000 RPM. Add in existing electrical demand and realistic design margins, you might be looking at a 1000 watt generator. This isn't going to work on the KLX.

There's a lot of wasted energy in the process of converting mechanical energy into electrical energy and back into mechanical energy. The half or three quarter horsepower compressor demand starts to look more like a three quarter or one horse shaft consumption.

It would not be realistic to use a 12V power supply to drive an electric supercharger. You would need a significantly higher DC voltage to run a reasonable motor to drive a centrifugal supercharger. It is complex, inefficient, bulky to "step up" or "step down" DC voltage (its a process of inverting DC to AC, transforming the AC, then rectifying back to DC). This won't be constant either; the voltage will need to be adjusted up and down to control motor speed to get a reasonable boost curve.

Even with voltage/speed control, you'll need a gearbox between the electric motor and the supercharger to increase the impellor speed to a functional RPM to make boost efficiently. More weight, more space.

And so on...

There's a reason the power adders that exist today are what they are. If a constant power adder is desired, traditional turbo or superchargers are the ticket. If intermittent power is desired, nitrous oxide.