KX Guru Racing

KX500 speed record?

Single cylinder 500cc dirt bike in stock trim.
It has to be stock and beat 134mph... I think I can do it...
And yes, I will use a KX500
I have one of only a few of the overdrive 5th gear sets ever made for the KX500...
The exact one that currently holds the speed record.
I know most of what was done to the current land speed bike and I have the help of the streamer class CR500 land speed engine builder as well as the most knowledgeable KX500 guy I have ever met...
Plus, Jason who builds all my engines weighs about 135lbs and is a expert rider.
So.... I just gotta build the bike...
I have been stashing away parts for it for some time... Just a few more parts and I can start putting something together...

Wow, that's a goal alright!!!
I remember years ago a uk bike magazine got a cr500 to 108mph I think. That was on bruntingthorpe 3mile runway. I'll check that top speed out.

I've gone back to square one with the tank. Just waiting at the engineers shop for the welder dude to arrive.

As you can see I've cut the bottom completely out now. The plan is now to mount the fuel pressure regulator on the tank and the controller for the water/meth injection on the tank. Also a manifold for the pressure/vac feeds for the various things that need a pressure reference.

More later.

Lol... no going back now
That's a nice fab job.
That's a area where I need improvement...

Bit of melting going on.

There is the finished article, with FPR, w/m controller and manifold (will be after a bit of machining) attached.

The main reason I have shifted all these items here is do the pressure/vac feeds are above the engine, with that pitot tube being in the intake after the carb the air will be wet with fuel,water and meth, all that liquid would condense or drop out in the pressure reference pipes, now if it does it will just run back into the engine.
Plus it leaves more room in other parts of the bike for other stuff.

That sure turned out nice.
Then again, I knew it was going to
I'm sure if anyone else is considering doing a turbo on their bike from scratch they will think twice after reading this thread.
I honestly had no idea how complex the system is and what all you had to take under consideration.

Thanks Mike, I'm pleased how it's going just now. There is just a few things to link up, a little bit of fab work and it will be running.
I would kind of hope someone looking at this thread would be inspired to turbo. Well if I can finish it and get it running good they might be. I have been counting all the time on the water/methanol spray being the thing that would keep it all together. I hope when it's finished you consider it to be a simple setup, that was what I am aiming at anyhoo.

Got the tank painted. Looking nice, should keep the rust at bay.

Now the pump, FPR and things. The pipe I am holding is fitted with a test point for a pressure check.

You can see in this next picture the inlet port on the manifold for the pressure/vac reference. It's threaded with a 1/4bsp thread. The MAP sensor for the ignition is fitted there too and it all looks like it was meant to be there. If you look closely at the FPR I took the bottom of the original FPR and sliced it down to about 3-4mm and added it in between the top and bottom of the FPR, this is to reduce the preload on the spring and reduce the base pressure.

Right, ready for a test.

Looks sweet....
Test it quick!!