Bob,
Actually Top Fuel rail dragsters and funny cars do not shift....they don't even have a transmission. a 5 disk clutch is used which is built to slip off the line until 1/2 track where the heat from slippage and 6500hp melts the disks to the friction plates. From there on out it is 1:1 direct drive and the tires grow in diameter due to centrifugal force, which provides a gearing change for the car. You have to rebuild it every run but considering they rebuild the engine every run too its not much additional work, LOL.
So no...high HP drag cars do not shift....they used to run 2 speed powerglides but that was decades ago.
I don't want to change the subject (especially considering this is an autocross/road race board

) but I do want to post this. Some wild facts about top fuel cars a friend sent me:
* One Top Fuel dragster 500 cubic inch Hemi engine
makes more horsepower than the first 4 rows at the
Daytona 500.
* Under full throttle, a dragster engine consumes 1½
gallons of nitromethane per second; a fully loaded 747
consumes jet fuel at the same rate with 25% less
energy being produced.
* A stock Dodge Hemi V8 engine cannot produce enough
power to drive the dragster supercharger.
* With 3000 CFM of air being rammed in by the
supercharger on overdrive, the fuel mixture is
compressed into a near-solid form before ignition.
Cylinders run on the verge of hydraulic lock at full
throttle.
* At the stoichiometric 1.7:1 air/fuel mixture for
nitromethane the flame front temperature measures 7050
degrees F.
* Nitromethane burns yellow. The spectacular white
flame seen above the stacks at night is raw burning
hydrogen, dissociated from atmospheric water vapor by
the searing exhaust gases.
* Dual magnetos supply 44 amps to each spark plug.
This is the output of an arc welder in each cylinder.
* Spark plug electrodes are totally consumed during a
pass. After 1/2 way, the engine is dieseling from
compression plus the glow of exhaust valves at 1400
degrees F. The engine can only be shut down by cutting
the fuel flow.
* If spark momentarily fails early in the run,
unburned nitro builds up in the affected cylinders and
then explodes with sufficient force to blow cylinder
heads off the block in pieces or split the block in
half.
* In order to exceed 300 mph in 4.5 seconds dragsters
must accelerate at an average of over 4G's. In order
to reach 200 mph well before half-track, the launch acceleration approaches 8G's .
* Dragsters reach over 300 miles per hour before you
have completed reading this sentence.
* Top Fuel Engines turn approximately 540 revolutions
from light to light!
* Including the burnout the engine must only survive
900 revolutions under load.
* The red-line is actually quite high at 9500 rpm.
* The Bottom Line; Assuming all the equipment is paid
off, the crew worked for free, and for once NOTHING
BLOWS UP, each run costs an estimated US $1,000.00 per
second. The current Top Fuel dragster elapsed time
record is 4.441 seconds for the quarter mile
(10/05/03, Tony Schumacher). The top speed record is
333.00 mph (533 km/h) as measured over the last 66' of
the run (09/28/03 Doug Kalitta).
Putting all of this into perspective:
You are driving the average $140,000 Lingenfelter
"twin-turbo" powered Corvette Z06. Over a mile up the
road, a Top Fuel dragster is staged and ready to
launch down a quarter mile strip as you pass. You have
the advantage of a flying start. You run the 'Vette
hard up through the gears and blast across the
starting line and past the dragster at an honest 200
mph. The 'tree' goes green for both of you at that
moment. The dragster launches and starts after you.
You keep your foot down hard, but you hear an
incredibly brutal whine that sears your eardrums and
within 3 seconds the dragster catches and passes you.
He beats you to the finish line, a quarter mile away
from where you just passed him.
Think about it, from a standing start, the dragster
had spotted you 200 mph and not only caught, but
nearly blasted you off the road when he passed you
within a mere 1320 foot long race course."