I’ve never tried starting from third, but starting from 2nd isn’t too uncommon. I imagine you can also start from third in certain cars, depending on the gear ratios and the torque of your engine.
Unless you’re really jamming your gears, you’ll get plenty of feedback from your gearbox that shifting 5->1 is a bad idea. I’ve tried a simple 3-1 downshift at too high engine revs, and the tranny simply wouldn’t let me do it. I would really have to force it in gear.
A Kawasaki ZX-10R can reach 102mph in first gear :eek:
Badmama : I submit for your consideration the 1994 Buick Roadmaster with the 350 cubic inch LT1 motor and the low-performance numerical 2.56 rear-end ratio.
Gear ratios were 3.06, 1.63, 1.0 and .7.
Tires were 235/70R15, I believe redline was 5500 and peak HP was 5000 RPM.
At the 5000 RPM mark, where it made its peak horsepower, the Roadmaster would be going 49 MPH. At redline it would be going 56 MPH.
There remains the question of whether or not you could persuade GM’s 4L60E tranny to let you run it past its horsepower peak…
Oh yeah. And the 1992 Ford Crown Victoria and Mercury Grand Marquis. There were two transmissions available, and one of them gives you a 1st gear redline of 61 MPH.
Tires, 225/70R15, rear end 3.08, tranny gear ratios 2.0, 1.47, 1.0, .67.
I have a '83 Corolla…I’ll give it a try on the way home tonight.
Oh wait…it’s only a 4 speed. 
Oh wait some more…80MPH is out of the question. :rolleyes:
I’ve seen some great speed-to-gear charts in print, but I’m searching for some online. As far as a car that can reach 50 mph in first, I believe the S2000 (and the RX-8 ) will … I autocross regularly, and it’s not unusual for us to hit 50-60 mph before the next corner. The guys who compete in the S2000s will very often complete the entire course in first gear and post some of the fastest times in any class. I know, not a cite, but I’m working on it. 
Way back during his misspent youth my cousin actually did this. He worked at a car dealership and was driving their little parts-getting pickup when he had the exact same thought (i.e. what would happen if I jam this thing into first at 50MPH).
The reason its hard to do is because you’re pressing the synchros (sort of rough, proto-gears which are ahead of the real machined ones) against each other and they won’t mesh until the speeds match. And at high speed first gear has to spin up to several thousand RPMs in order to match the output shaft’s speed. If you listen closely when you’re downshifting you can actually hear the input shaft and clutch speeding up to match the output shaft.
Also, something most people don’t realize is that whenever a manual tranny is in gear the clutch disc spins at the speed of the output shaft x the gear ratio regardless of whether or not you release the clutch pedal.
What can happen (and did happen in my cousin’s case) is that when the clutch disc spins much faster than its ever intended to (say approaching 10,000 RPMs in a regular car) cetrifugal force will cause the clutch disc to explode.
Even if you did get it into first gear and let the clutch out I don’t think it would make the engine destroy itself. I think the clutch would slip and/or the drive wheels would skid (i.e. from not being able to spin fast enough). I don’t believe that the drivetrain could force the engine to over rev. Rather the engine’s resistance would make something in the drivetrain slow down or fail first.
Top speeds in each gear for a '03 S2000:
43, 66, 91, 116, 139, 146 (drag limited).
From August 03 Car and Driver.
That’s what I was looking for. Thanks. Just shy of 50 in first … 80mph downshift would probably send the little Honda singing to about 16000 rpm … for a very brief moment before something decided to end the show in a spectacular way.
Tom Wolfe’s novel Ancestral Vices has a moment like this. A slightly retarded woman is suspected of being a murderer/assailant, but it hinges on whether or not she can drive. A police officer decides to conduct a test, putting her behind the wheel of a police car. She panicks, putting her feet on the clutch and gas pedal, and the car starts to roll down a steep hill (why conduct a driving test at the top of a hill? don’t ask). In his desperation to stop the car, the officer tries to kick her feet off the pedals, but the gearshift keeps getting in the way. He shoves it aside, putting it in reverse, and kicks her foot off the clutch (keep in mind that this is a British novel, so the driver sits on the right).
The car is rolling forward at about 90MPH, with engine revs at 9000. Hilarity ensues.
It can. It happens when a racer “misses a shift” – intending to shift from, say, 4th to 5th, but accidentally shifting from 4th to 3rd. It is possible to make the shift, and of course the driver lets the clutch out and mashes the accelerator to the floor as soon as possible. Engine disintegration ensues.
Nah, that was a mistake on my part. It was a 4 speed gearbox and had a crummy feel to it so I thought I was putting the lever forward into 1st and not 3rd.
A moron I used to live with constantly swore at his car because its 1.4L engine couldn’t manage a hillstart, at low revs with two people and luggage in the car :rolleyes:
And I was sure I’d read somewhere on here before regarding the synchro’s on a gear box like Hail Ants said.