Does anybody make SIX INCH OD aluminum driveshafts?
Is there any solution at all for a 75" shaft that needs to spin 7000 RPM? Carbon fiber/titanium/beryllium hybrid composite with integrated active Eigen-mode compensators and costs $140,000?
The responses I've gotten from driveshaft shops are amazing.
"You will have to convert to a 2-piece shaft for that length. Just delete the factory fuel tank so you can fit in a crossmember for the center support, should be no big deal."
"No."
"We don't do trucks."
"I wouldn't recommend spinning any shaft that long of any size/material over 3000 RPM, even if we, a professional high performance driveshaft specialty shop, built it with the best of our cutting-edge tech and craftsmanship."
According to interwebs critical speed calculators a 5" OD/.125"-wall aluminum shaft that's 75" joint to joint is good for 5700 RPM, which with my gear and tire nets only 130 MPH. If there were such a thing as a 6" OD driveshaft, then at that length crit would be 6900 and a speed of 157. This would be good enough. It does not need to handle 3000HP, which seems to be the only criteria driveshaft shops are used to dealing with.