ORIGINAL: downunder
ORIGINAL: 1QwkSport2.5r
I wish there was a way to stick a prop equivalent to the load of a car's drivetrain to find out what rpm these car engines really hit.
The only relatively simple way to know how many revs a car engine actually turns on the track is a method I used with my son's car. I took a video of it then played back the video on my computer and recorded the sound. Then I ran the sound through a program (Goldwave) which showed the actual waveform. The screen grab below shows this waveform after slowing it down 100x and now the individual exhaust pulses can be seen. What's kind of neat is that by playing it back 100x slower the pulses sound a bit like flub...flub...flub...
. Now looking at the screen grab and starting with a pulse that lines up with the .03 second mark and counting the number of pulses to the .07 second mark (where a pulse lines up again) there's 19 pulses in that .04 second duration or 1/25th of a second. So multipying the 19 pulses by 25 gives 475 per second which is 28,500 per minute. On another recording down the main straight his engine was turning 36,000 revs. This was with a Mach 28 engine on 80/20 all castor fuel but with compression raised to 13.4:1 in a Hyper 7.
I'll look into that software. Definitely a higher-tech method than the norm, but not the instant gratification I was hoping for...
I have a few other ideas I'm going to try when I get time. New family and work constraints will be limiting my free time for awhile, so this will have to be on the back burner for now.
Did you just machine the head on that Mach .28 engine?