We were discussing how much weight reduction affects 1/4 mile times.

I stated that if you take 600 lbs off a car, that should equal to a second or so off a 1/4 mile time. According to him, 600 lbs won't make anywhere near that much difference. That it'd gain about .20 of a second.

Any thoughts?

 

100lbs = .1 (1/10) of a second.

 

That is what I said. But after hearing how wrong I am for the past hour, I decided to ask haha

 

Not really what you said... you said 600 lbs is a second or so... 600 lbs would be about 0.6 seconds... in drag racing, 0.6 seconds is a looooong way from 1.0 second!

 

Ah, yes. BUT .60 is a long way away from .20 also.

Friends actual words were ".20 if you are lucky. If you take 600lbs off a car you aren't going to be able to feel a difference."

 

If you remove 600 lbs from a 2800 lb car, then yes that is a big difference!

I can feel a difference when a 150 lb passenger is riding with me.

 

http://robrobinette.com/et.htm

 

ET = ((Weight/HP)^(1/3) * 5.825)

or

Weight = ((ET/5.825)^3 * HP)

Therefore, if your car has 200hp and weighs 2800lbs it would have an estimated ET of 14.03908. If you drop 600lbs to weigh 2200lbs, the estimated ET will change to 12.95468, for a total change of 1.0844.

However, if your car has 300hp and weighs 4000lbs it would have an estimated ET of 13.8126. If you drop 600lbs to weigh 3400lbs, the estimated ET will change to 13.08424, for a total change of 0.72836.

Therefore, the effect of losing 600lbs depends on the other factors. Basically, the heavier the car the less the difference per pound, so the Camaro/Mustang guys will not see the savings that the Honda guys will.

 

The numbers were based off an N/A S5. I guessed that at roughly 2800lbs and 160hp, a second would be shaved off.

 

If you've managed to shave off a second on your times without upgrades, probably means you're getting better at drag racing. If you're really looking for quick times, you're going to need a much larger package of some sort.

 

Wut?