Is it to early to speculate on ride length? Any educated guesses?
No insider knowledge, but piecing together 3 things we've learned. "One of the World's longest Indoor Coasters", Launch coaster, and on the intensity level of BTMRR. I will make a guess.
Mindbender is the longest indoor coaster at 4,198 ft... however it says "one of" not the longest. It will probably be closer to Rock n Rollercoaster at 3,403 feet.
Launch coasters obviously don't have the lift hill time that traditional coasters do.
Watching a Big thunder Mountain POV give me the following times:
22 seconds from start to lift hill
38 seconds on lift hill 1
30 seconds from lift hill 1 to lift hill 2
25 seconds on lift hill 2
26 seconds from lift hill 2 to 3
20 seconds on lift hill 3
25 seconds from lift hill 3 to brake run
20 seconds from brake run to unload
Now to convert this level of intensity to a launch coaster of 3,500 feet!
Big thunder mountain has a length of 2,671 feet
BTMR spends 83 seconds on lift hills. Assuming the lift hill is 5 mph. BTMR travels about 600 feet on lift hills
BTMR spends 20 seconds from brake run to unload and travels ~7mph. BTMR travels about 200 feet on the brake run.
The rest of the run covers the 1,871 feet in 98 seconds for an average speed of ~13mph (slower at tops of hills, faster in valleys)
Taking all of this into account... I predict
~20-30 seconds from load to launch (400-500 feet)
~10-20 second stop before launch (similar to SDD)
~20 seconds from brake run to unload (~200 feet)
Leaving ~2800 feet of track between launch and brake run. IF it averaged ~13mph it would take 2 minutes and 27 seconds
Total run time of about ~3 minutes and 40 seconds.
For reference Rock N roller coaster from launch to unload is about 1 minute 10 seconds
Tron is from launch to unload is about 55 seconds.