|Home of the Jet Powered Go Kart, and More!|
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10/10/05- The kart has been successfully sold to a lucky owner. I wish him the best of luck in the future with the kart.
8/30/05- As I have announced on the News page, I am selling my turbojet powered kart. As a special courtesy to fans of Turbokart.com, I will offer it here on Turbokart.com before putting it up on ebay. If anyone is interested, please email me.
I never got around to putting a second engine on the kart, or an afterburner, but perhaps it is something that a new owner might consider doing. The kart has seen very little use since I completed my turboshaft powered kart, and has always been stored inside of my house, put on display for guests to see. Since I haven't run the kart in a while, I will go through it with a team of professional mechanics, and freshen up any components that need servicing. The kart is in good running order, but I will make sure it is running as well as the day I finished building it, before I sell it. I will test run it one more time to ensure this, and also to reminisce about the early days of my gas turbine projects.
Please email me if you are interested in owning The Original Turbokart.
6/30/02- Not content with 71.2 mph, we have decided to get an early start on upgrading our jet go-kart. We plan on adding an afterburner which should boost thrust significantly, and will also look cool. We are going to need a fuel nozzle, an igniter plug, a fuel valve, and a few switches to run everything. We plan on just running another fuel line from the fuel boost pump on the kart. Keep watching for updates.
6/24/02- This last weekend we ran the kart at the old airfield again. The last time we ran here, we topped out at around 55 mph. For this test, we made a bunch of fine adjustments and they really paid off. We adjusted the fuel governor to allow the engine rpm up to 104%, we increased the tire pressure to reduce rolling resistance, we greased up the wheel bearings, etc., and with a very gentle wind at our backs, we recorded a pretty decent 71.2 mph as recorded on GPS. We are pretty happy that we finally reached our goal of 70 mph, and now we can work full speed ahead on the next project.
The kart ran smoothly over the old runway, and the engine accelerates the kart up to speed quite quickly. But we don't expect to see any more speed out of the kart, at least not until we add a second engine and a pair of afterburners. Oh, the possibilities...
We recorded some more video footage. Keep checking back in the next few days to see it.
By the way, we were kicked out of the airfield again. It looks like we are going to need to take it to some kind of racetrack. A short oval might be a good place to drive it. (next entry)
6/17/02- We will be taking our jet powered kart out this coming sunday morning for another big run. We will be shooting more video and taking some more pictures. We hope to acheive 70 mph after making a few minor changes. We have been taking the kart out for a few quick runs here and there, and everything is working perfectly. (next entry)
5/27/02- Today we ran the go-kart again at what used to be a World War II Naval air base. We took the kart out for some high speed runs, and to really test the handling of the kart. The purpose of these tests are not just to see how fast we can go, but also gather information for our turboshaft powered go-kart, which we may compete with one day. Of course, it is also a lot of fun to drive, and the crowd it attracts is amazing.
We made a number of high speed passes with the kart, and we reached a top speed of around 55 mph, but with the tach only showing N1 97%, we are sure we can get even more speed out of it. 70 mph seems reasonable, although for any more than that, we'll probably have to do some major work. Eventually we'd like to add another jet engine to the kart.
The kart needs some more very fine tuning before we consider it complete. We have to figure out why rpm was only showing 97% when we have set the throttle stops for 104%. It may just need a minor adjustment.
At the end of our runs, we didn't have enough battery power to start the engine again, so we decided to call it a day. It is essential to have plenty of battery power to get the engine running, or you can risk a hot start. The small onboard batteries are not good for engine starting, but rather only for running the electrical accessories.
After some nice runs, we were told to leave. Thanks US Park Police! (next entry)
5/24/02- The modifications of the kart were completed and we did a quick shakedown run of the kart in front of the shop. Everything worked perfectly. The electric oil pump works great, and a key switch cuts out the starter motor after the engine is running, to keep the starter from kicking back in unneccessarily. We will post some updated pictures of the kart soon. (next entry)
5/13/02- Some of the basic planning has started for Turbokart II, our 100 horsepower wheel driven kart. Check it out here. We promised ourselves we would not start buying materials for the next kart until we reach 70 mph on our first kart, just to give us a goal. We don't think we'll have much problem, and we may be going for it this weekend. (next entry)
5/12/02- With things busy at work, it has been hard to put the time into the kart, but today we made some good progress, and hopefully the kart will be ready by the end of the week. We have added the electric oil pump, lowered the engine, and made a few overall adjustments. We must still find a better way to mount the control box/tachometer, and we must add an oil pressure gauge. (next entry)
4/30/02- Turbokart is stripped down and back in the shop. We must make a few changes to it before we feel we can run it regularly. We want to do at least one more fun shakedown run before we start doing some high speed testing. The changes we plan on making include the following:
-Adding an electric oil boost pump and oil pressure gauge
-Lower the engine mounting
-Add a starter cutout switch so the starter will not automatically re-engage if the engine flames out. (This could damage the starter clutch!)
-Fix any leaks and any other minor problems
Hopefully the repairs should be done in about a week. (next entry)
4/19/02- After some analysis and talking to a few a people, we decided we are going to have to make a few changes to the engine. We realized we were still having oil flow problems, and this could lead to an expensive engine failure. The JFS engine is not designed to have an oil cooler, and therefore, running one requires a little bit of cheating and some tricky plumbing. With the layout of our kart, this would be very difficult to do properly. Instead of risking problems, we decided to add an electric oil pump to pull oil out of the gearbox and circulate it through the cooler. This should assure proper oil pressure at all times, which will put our minds at ease. The oil pump we will use is actually a standard automotive electric fuel boost pump. We will connect it to one of the 12V batteries through an on/off switch. (next entry)
4/14/02- After some initial difficulty in getting oil to flow from the oil cooler to the accessory gearbox, and in getting the engine to start, we had our first successful test run! After some initial reluctance, the engine started right up and ran beautifully. We adjusted the throttle to range between 68% and 103% N1, and the engine responded well to throttle inputs. At idle thrust, the kart very slowly rolls forward, but at full power, it moves away quite quickly. It's not a dragster, but it moves quicker than we expected. Once rolling, the acceleration is quite strong. For our first test, we only went about 35 mph, as indicated by GPS, but the kart will clearly go a lot faster, given enough room to accelerate.
Video Stills of our first test run
The kart wasn't as surefooted as I remembered. It was somewhat twitchy and over responsive to the steering at higher speeds. This may have something to do with the added weight in the rear. Also, we both noticed that the front had a tendency to lift slightly under acceleration. When turning, the kart loses a lot of speed because of the solid rear axle. Unlike a wheel driven car, the engine power can't be used to slip the rear tires, so the kart just slows down. Despite these drawbacks, the first test was definitely a success. We will probably just live with the chassis problems because we are not going to be racing this kart or anything like that. It is just for fun. However, we will collect valuable information for our next turbine powered kart, which will be wheel driven.
The kart in action!
4/11/02- There was some initial concern that the intake duct screen would be too restrictive. After talking to a few people, it seemed as if the intake duct we fabricated would be ok. However, just to be safe, we decided to increase the intake area. Instead of adding another section of pipe, or making the mouth larger, we decided to simply burn some holes around the perimeter of the duct tube. We then covered the holes with wire mesh screen. This has significantly increased the intake area, while still providing adequate FOD protection. The kart is ready for its first test, which will take place this Sunday morning. (next entry)
4/5/02- The kart is now officially 100% completed. The kart frame was covered in oily grime and dirt. We used brillo pads and a lot of hard scrubbing to clean it up as much as we could. Then, we added the original kart bodywork. I had to cut a small piece out of the plastic to get the bodywork to fit around the bracket we added to hold the oil cooler fan. After some finishing touches, the kart is complete. Our first test is scheduled for next weekend. We can't wait! Stay tuned… (next entry)
4/1/02- After a bit of a vacation, turbokart is complete, and it is back home! Some time this week, we will give it a bit of a cleaning, put the bodywork on, and put the final few touches on it. We plan on taking it out for the first test very soon. Keep checking back to see the results. (next entry)
3/08/02- We got a lot of work done on the kart in the last few days, and now it is completely done except for filling the brake cylinders and for some small finishing touches, like adding the plastic bodywork and cleaning up the kart. It's a little frustrating because tomorrow would have been a perfect day for a first test run, but without brakes, its probably not a good idea. It's tempting, though… Today we finished connecting all of the fuel lines, and electric lines. We mounted the starter control unit onto the front bodywork bracket. We also installed a switch for the electric fuel boost pump. We mounted the starter relay onto the other front leg of the mounting frame. We connected the throttle cable to the linkage on the engine, though I am going to have to fine tune the throttle stops to get full power and proper idle speed. A jet engine builds thrust exponentially with rpm, so I will have to make sure I am getting maximum rpm. We also fabricated an inlet duct with a screen. A jet engine draws in large quantities of air. Even this little engine pulls in 1.6 lbs. of air every second at full power, and that means that if there is any dust or debris nearby, it can get drawn in as well. To prevent FOD, the engine needs a screen. We welded some pipe of differing diameters to make our inlet duct, and then welded a large gauge steel grating to the front of the duct, to support the fine mesh screen, which we clamped in place. We made sure to make the opening of the duct larger than the actual compressor inlet, to be sure that the screen creates as little air restriction as possible. Too much restriction will make the governor supply more fuel for a given rpm, and that could make the engine run hot. I'm still not totally confident that there is enough intake area, but we will have to see. (next entry)
3/04/02- Today we did a lot of work on the kart, and it is very near to completion. I received the brakes and the new rear tires, and we mounted everything on the kart. We succeeded in lowering the oil cooler in relation to the engine by raking it back at a sharper angle, so oil scavenging shouldn't be a problem. We also removed the fuel tank so that we can wash out the remnants of the 105 octane racing gas/2 stroke oil mixture, and so we can run the fuel lines from the tank to the boost pump. Removing the fuel tank required taking apart the steering column. (next entry)
3/01/02- Today we made a few adjustments to the oil cooler arrangement. It is important that the oil cooler be lower in height than the engine gearbox sump. Originally we tried mounting the engine as low as possible, and then trying to fit the oil cooler in as neatly as we could, but as it turns out, the cooler is still a little too high in relation to the engine. We are going to raise the engine about an inch, and try to lower the position of the cooler to satisfy this requirement. By the way, the brake calipers are done. I'll be picking them up sometime this weekend. (next entry)
2/26/02- Nearly two weeks later and the brakes are still not fixed, but it shouldn't be long before they are done. I also sent away the rear rims to have new tires mounted. We want the tires to be in good condition just in case the go-kart actually goes fast. With 100 pounds of thrust, I don't think that 100 mph would be too unreasonable, even if it accelerates slowly. Performance test results will be posted on the website. (next entry)
2/21/02- We have mounted the engine oil cooler to the kart chassis, and have also mounted an electric cooling fan. The oil cooler sits on the same brackets that the radiator sat for the 2 stroke piston engine. The cooler is a standard automotive oil cooler, and the fan is actually a small fan one would mount on the inside of a truck cab. Without an oil cooler, this engine would overheat within five minutes of running. (next entry)
Oil cooler and fan
2/16/02- I have brought the JFS turbojet into the shop today, and we mounted it onto the go-kart chassis. Naturally, it was a perfect fit. It took a little getting used to how much the engine sticks up and out past the boundaries of the go-kart frame. On our next go-kart, we will put more effort into designing a more space efficient mounting system. Ideally, we want the engine to be as low as possible, and if possible, in front of the rear axle. (next entry)
2/13/02- The engine mount has been bolted to the rear of the chassis. The fuel boost pump has been mounted to the right side of the chassis, in front of the battery pack, and the fuel pressure regulator has been mounted to one of the legs on the mounting brackets. There is some bad news though; the go-kart's brakes are frozen and seized up, and aren't working properly. I will take the calipers off of the kart and have them fixed. (next entry)
2/12/02- The go-kart chassis has been further modified, by welding two longitudinal steel flanges onto the steel tube crossmember. The steel plate of the engine mount will sit on top of these flanges. They will be bolted, and rubber bushings will help to isolate the engine from any shocks. Also, two 12V motorcycle batteries have been mounted to the right side of the seat. They will be wired for 24V, to provide power to start the engine. (next entry)
2/09/02- The go-kart's rear frame has been removed, and a new steel tube cross member has been fabricated. The cross member will be welded to the rear of the kart, and then stabilized with another steel tube brace. The cross member and brace will support the engine mount, which was also fabricated in the shop, from steel plate and angle iron. (next entry)
2/1/02- With the JFS-100 turbojet engine completely operational and fully tested, the focus shifts on the go-kart. The kart chassis was recently stripped down to its bare components; the frame, the steering, the brakes, and the wheels and tires, and the bare chassis has been taken to the shop where it will be modified to accept jet power. (next entry)
February 2002- The chassis was brought to my shop to be modified to accept the turbine engine. (next entry)
January 2002- The next step was to strip down the go-kart chassis. We spent two evenings and just went at the go-kart. We removed everything that wasn't needed from the chassis, including the body work and mounting brackets, the engine, gearbox, chain and sprockets, shift lever, clutch lever, fuel lines, radiator and hosing, and more. (next entry)
December 2001- We received the engine mounting brackets from Arfons. These brackets are like ears on the front and rear of the engine. The two front brackets are mounted where the lifting handles are installed, while the rear brackets are mounted where the power turbine was mounted. With the brackets on the engine, I brought the engine to my shop, and had a simple mounting frame made of steel plate and angles. The angles suspend the engine over the plate, which will be mounted to the go-kart chassis. (next entry)
November 2001- After a few more fine adjustments, we prepared for the final test. In this test, we went to full power 104%, and let the engine run for very long periods of time. We noticed the jet pipe begin to glow red hot, though this is normal. We shot some video of this third and final engine test. Take a look. After this test, we decided we were ready to run the engine in the go-kart. From here on in, our focus would shift to the go-kart, and mounting the engine. (next entry)
Late October 2001- The second test run occurred a few weeks after the first, after a few adjustments were made to the oil cooler plumbing and throttle stops. With the second test, we got a little more daring. We ran the engine at higher power settings, approaching 90% and more, and let it run for longer periods of time. The engine is LOUD! With the engine running at idle power, I ran all the way down the block, and could still hear the engine as loud as if it were right next to me. Later on, a friend of ours who lives all the way down the block asked what the noise was, and he was inside of his house. We got a few complaints, so we decided to conclude our second test. (next entry)
Early October 2001- While Arfons had the engine, I also instructed him to install the jet pipe, a fuel control, and configure the engine to run with an oil cooler. This way, when I received the engine, it would be almost ready to go. Installing the jet pipe requires removing the power turbine nozzle, and bolting the jet pipe in its place. The accessory gearbox oil pump now sends oil out through oil lines to a typical automobile style oil cooler. And the throttle is made by replacing the governor adjustment screw with a plunger, which is then actuated by a simple lever mounted onto the side of the gearbox. It controls the power from a range of 68% N1 to 104% full power. After Arfons completed his work on the engine and sent it back, it was time to test it again, this time in pure turbojet form.
After a couple of attemtps, the engine started right up. A flame shot out of the exhaust nozzle with a loud popping sound, and then as the compressor continued to accelerate, the flame got smaller and ultimately disappeared. As the engine continued to accelerate to 68% idle, the engine stand began starting to slide against the floor. Even at idle speed, the engine was producing considerable thrust. For the first test, we decided to let the engine run at idle speed only. We started the engine up and shut it down about 5 times, and made some observations. The engine basically ran perfectly. (next entry)
August 2001- With a new, heavier duty starter relay hooked up, we made our second attempt at a test run. This time the starter relay remained intact, and the electric starter spooled up the engine, but the fuel valve failed to open and we couldn't get the burner to ignite. After a few attempts, we tore down the test rig and decided to try to figure out what was wrong.
After numerous attempts to try to figure out what was wrong, we finally conceded that we would have to send the engine to Arfons and have him take a look at it. (next entry)
July 2001- Arfons finally completed and sent over the start control unit and a few other pieces needed to run the engine. We wanted to a do a test run of the engine before putting the jet pipe on. In order to do so, we would have to replace the power turbine nozzle.
We set up for our first ever test run of a gas turbine engine. Keep in mind the engine did not have a jet pipe or a throttle control. It would simply start up and immediately spool up to full power. It would only produce hot gas and loud noise, and we had to be careful to not to let it run for more than five minutes. Upon hitting the starter switch, the starter relay promptly blew… (next entry)
June 2001- While waiting for Arfons to complete the start control unit and digital tachometer, we procured the necessary supplies for our first test run. I ordered a fuel boost pump and pressure regulator from Summit Racing, fuel hose, clamps, 2 batteries and connectors, turbine oil, and kerosene for fuel. (next entry)
May 2001- With the decision to convert the engine into a turbojet, we got started on removing the power turbine and output reduction gearbox from the engine. The power section is completely independent from the rest of the engine, so it is just a matter of removing approximately 10 bolts and a few electrical connections. Apart from one or two of the bolts being tricky to access, the power turbine came off without a hitch.
Removing the power turbine exposed the power turbine containment ring. This 1'' thick titanium ring prevents what is referred to as an "uncontained event," which is basically when the metal turbine blades come ripping out of the side of the engine due to an overtemp or an overspeed.
Prying the containment ring off was actually quite difficult. After it was removed, the power turbine nozzle or stator was the last piece left to be removed from the engine. The nozzle was easily removed, exposing the gas producer turbine. (next entry)
April 2001- The Allied Signal JFS-100/13A jet fuel starter arrived from Avon Aero supply. Though the engine was in running condition, we didn't have the necessary equipment to run the engine. (next entry)
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