Last Tuesday I went to the track and a friend was watching us race. He had never been in a run down the track and no one else wanted to take him, so I offered. Well I ran a 15.6 with a 2.3 60' with him in the car. He weighs probably 180 lbs at the most. Next run, I ran by myself and pulled off a 15.1 with a 2.3 60'. There was nearly a 3 mph difference between the runs also.

In conclusion, 1 passenger in the car(180 lbs) will ADD nearly .5 to your 1/4 time.

 

Yep, this was discussed earlier and I think a formula came up that said for every 100 pounds you have you lose 15 HP.
Good Luck,
Paul

 

Thats sounds about correct if you play with lbs/hp ratios.

3300/222=14.864
3400/222=15.315

 

Good run without your buddy, But I didnt know that one passenger could affect your time by that much.

 

You ran twice, once with and once without a passenger, correct? I don't think you came any conclusions...your logic about the passenger is like me saying "It was sunny outside, I came inside and changed my clothes, and then it was raining outside. In conclusion, changing clothes causes rain."

If you would have done like 2, 3, 4 or more runs with and without the passenger, I would believe your conclusion, but until then, I'm going to have to question .5 off a quarter mile time for a 180 pound weight reduction.

 

I ran 6 times....1 time with the passenger and 5 times by myself. The time with my passenger was against the run after. Both runs had VERY similar 60' foot times.

 

There have been several threads about this recently. When I use one of those horsepower formulas, I get about .15s reduction (or gain) for each 100 lb added/removed from the car. However, just like you, when I ran with my ~200lb friend, I had .6s added to my clock! I agree that 180 lb would add .5s to yours.