Quoted:
Damn I'm retarded, I was asking how car makers got their times.
Here's one test procedure. It's very much a trial-and-error process to get the best times (spin vs. bog). These are usually measured by some GPS based data acquisition system, like the Racelogic VBOX. Typically you keep 1/4 tank or less in the car.
-Rev to 3krpm, hold steady.
-Feed in more throttle as the clutch is released. Aim for some, but little wheelspin (this is how I'm most successful –– if you read a vehicle dynamics textbook, it'll probably say 10% wheelspin is best...at least that's what RCVD says).
-Foot to the floor (if possible).
-When shifting, speed is the name of the game. Clutch in, gas off, rip it to 2nd (I would
never do this to my own car –– but for testing purposes, you want to just jerk that thing back RFN). Release clutch, full throttle. I think a good time would be in the 200ms range, but I'd have to check data/notes.
-Repeat to 3rd if necessary.
One interesting fact. You can be the Stig, follow this procedure (or even a better one) to a T, and you
still wont match any car rag times. Depending on the outlet (some are far worse than others), they might give a few feet of rollout (this is almost always done on 1/4 mi times, but sometimes even done on 0-60 times), adjust for atmospheric conditions, etc.
ETA: As
DarkCharisma said, these are usually done on a hot dry tarmac, typically a straightaway or VDA pad. It's also common to lay down some rubber for your launch area (this is one way to warm up your tires, but I would actually recommend driving in circles both directions first to get the interior of the tire hot). The numbers collected this way are typically NOT published and used for internal purposes. They're typically collected by (well-trained) engineers.