RE: Thunderboat speed and prop questions
GPS speed are set by calculating the time it takes to travel either 20-30 feet( i can't remember the article). Take your GPS outside and start walking, see how far you go before it registered the speed.
SAW record are set by calculating the time it takes to travel 1/16 mile (or 330 feet). It doesn't matter if you hit 90 in the last 30 feet when it takes you 5 seconds (figurative speaking) to run 1/16 mile. You will not get the 90 MPH record even though your GPS says 90(assuming your GPS is dead on).
See the difference?
Beside, the QD/dragcat combo will go faster in the straight away than a sprint cat/SS combo(all other factors being the same). Even then the QD powered drag cat can't even break 78, what makes you think the SS powered sprint cat will set the record at 78.4?