Focus Fanatics - View Single Post - Write-up: How to determine approx. HP gains from removing weight!
View Single Post
Old 08-11-2005, 05:58 PM   #8
Focus Enthusiast
Join Date: Aug 2005
Fan#: 26198
Location: Portland, Maine
What I Drive: 94 Grand Cherokee 55k mi, standard

Posts: 65
FF Reputation: 1 Taiden Good Standing Member
Buy-Sell-Trade Rating: (0)
Originally posted by SD_Focus
Those calculations are silly. If I take 1,000 lbs off of that 2,600 pound car, its going to be faster than a 50 horsepower difference. My bike weights something like 400 lbs and has 96 horsepower. If I took off 2198 lbs to make that focus 400 lbs then that would be a 110 hp increase? Sorry but a 240 hp 2,600 pound car isn't gonna keep up with my bike, but a 130 hp 400 lb. car would beat the hell out of it. Those calculations might make sense for maybe the first 100 pounds you lose.
It's silly because you aren't realizing the the equation works on a curve. Every time you remove weight, you have to redo the equation and it gives you a new lb/hp ratio.

Example: if your car is 1000lbs and you remove 100lbs, and then another 100lbs you will get a different amount of HP "increase" with the equation than if you take 50 lbs off and then 150 lbs off. The more you rerun the equation and add up the gains, the more accurate you will be. If you run the equation for every 1 lb you remove, it will be accurate and make more sense. I hope that made sense.

To summarize, when your weight changes so does your lb/hp ratio, so everytime you change the weight you must run the equation a second time. To make your math more accurate, if you run the equation for each pound you remove it will be far more accurate.
I doubt anyone on a Focus board would be interested, but I'm selling a '94 Jeep Grand Cherokee with 55k miles, all power options and a manual tranny. PM for details. :)
Taiden is offline  
    Reply With Quote