Friday, March 7, 2008

Are you doing 1/4 mile on your tuned BMW M5?
















I am here for ya bud.....
  • 1/8 gas (refill 4-6 liters at a time)
  • No neutered launch control - useless bmw m5 tuning
  • P500S / S6, EDC: Comfort
  • Hit the gas when the last yellow light is lit (you need to play around here)
  • The important thing: Step on gas 1/3 - 2/3 down when you are ready to go....you need to feel the car hook up. You will need to modulate how deep you press the gas and the rate you nail the gas pedal
  • Don't use the hud, it is too slow
  • Must avoid hitting the rev limiter
  • Shift when the needle hits 8000 rpm, by the time it actually shifts, you are at redline
  • Burn outs will help with 60 foot times but I don't think it is necessary
  • If your goal is a low E/T, use 22 psi and burn out
  • If you goal is a high trap speed, use 40 psi
  • I would just go with stock.....
Our engines are not affected by hot lapping so don't worry....the car will run strong all day long.

Look at your timeslips between runs to govern your behaviour. If you are under 2.1 seconds for 60 foot times, you are doing well.....anything under 2 seconds is great....the rest is a video game.

One more thing

The biggest impact on your 1/4 mile ET is what happens in the first 60 feet. While a 20 inch lighter wheel/tire combination will carry more speed from a rolling start or even in the last 1/8th of the track, a 20 inch wheel will be an impediment in the first 60'. Whatever you gain at the top end of the track will not be enough to make up for a bad launch. You MAY have higher traps, but your ET's will likely be no better than if you ran on your 19s, and probably worse.

The reason is the sidewall. If you are going to run at the strip, you should NOT have a stiff and paper thin sidewall. The larger the rim, the thinner the sidewall on the tire. So assuming that the condition of the tires on the 19s and 20s are comparable, the 19 inch tire will have a thicker sidewall. It allows more flex at the line and allows the tire's contact patch to work better, giving you a better launch and 60' time. If you have ever seen a wrinkle slick in action on a 9 second car, you'll understand.

People who really want to devote time and money to the track buy a dedicated set of light rear wheels and drag tires. They buy the smallest rim that will fit (clear the rear brakes), which gives them a tire with a larger sidewall. The combination of sidewall and a special sticky tread compound beats the pants off of most street tires. You really need to commit to the 1/4 mile to invest in this because it is a PITA to change wheels for the strip. (Some guys change wheels at home and drive to the strip, but God help you if you get caught in the rain on the way home riding on drag radials.)

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