Bruce Simpson

[Bruce Simpson]

I have built a lot of projects over the past 40 years and several were gocarts. A 100 lb trust engine on a gocart is very slow take off. It will get you up to about 100 mph top speed but that will take a whole mile of flat level road with no head wind or curves and several minutes to get up the speed. It can be fun at first but it gets boring pretty quick.

It depends on the power-to-weight ratio.

If you want 1G of acceleration (slow by drag-racing standards) then you'll need an engine that puts out as many pounds of thrust as the vehicle (and driver) weigh.

This pulsejet dragster I built a few years back had a total of about 320lbs of thrust but was pretty heavy (made from 1" RHS steel). Never the less it gave a satisfyingly strong "push in the back" for whoever was driving it and we clocked it over 100 (using a bike speedo that only went to 99) several times on a 1km long runway (still allowing room to stop before hitting the grass runoff at the end).

If you want a FUN gocart build this. http://home.earthlink.net/~gary350/gokart15.jpg

Yeah, if I build another jet-powered vehicle it will be a turboshaft -- reaction propulsion is fun but it's not as effective as some good old foot-pounds of torque!

[metiz]

Hello Bruce

Do you have a raw version of that video lying around somewhere? I realy hate that slapped on turbine sound

[Bruce Simpson]

Hello Bruce

Do you have a raw version of that video lying around somewhere? I realy hate that slapped on turbine sound

No, that was taken from the final-edit of the TV show on which it appeared.

Idiot producers and directors seem to think that all jet engines should make a turbine sound (sigh!).

When Discovery channel filmed that dragster they had to wrap their microphones in foam because the noise levels were just too high and the audio was severely clipped, even with the gain turned right down.

Standing directly behind two huge valveless engines (running) is an experience that has to be experienced to fully appreciate. Even with grade 5 hearing protection (*and* ear plugs), the noise is deafening and the pressure waves rattle right through your skull to your inner ear. It's also like someone is beating you with a big pillow -- you can feel your whole body being battered - even at 20+ metres.

The XJet is a totally different experience. When you stand behind that you almost instantly get a feeling of pins and needles in your extremities -- it's *very* odd and quite disconcerting.