Im not sure if this is the right spot for this question. Ok I have heard that for every 100lbs you shead off your car you gain 10hp to the wheel or something of that sort, does that work the other drection, as in if I added 100lbs to my car would I lose 10hp to the wheels? Would it be more? Why I ask is im trying to see what the effect of putting the stereo im building into the car is going to have.

 

The WHP would not change, but the car will feel slower and quicker when weight is shed or added. However I'm not sure to a rule of thumb for the RX8 as how lbs. reduction makes it feel like it gained 10hp.

 

I have heard 10lbs= .01s on the 1/4 mile i have no evidence to back that up, just what I hurd

 

i heard something similar with rotational mass such as 10lb lighter wheels is like taking off 100lbs from the chasis... either way 100lbs is alot so if your speaker system ways that much thats crazy! get some lightweight subs or something

 

This is not completely correct. Although your engine's power is still the same reducing weight will lend to less dissipations, hence more power used for moving and less for winning the resistances. I dunno how to explain this in english and i always sucked at physics but it should be something like that

 

Force = mass (kg) x Acceleration

 

yep, the less weight your car have, the faster you car can be with the same engine power.

Reducing weight at the wheels, means the engine has to move much less mass directly. Also diveability and handling will improve with lighter wheels, the car will turn quicker.
Reducing weight at the chassis means, the Engine has much less weight to pull. So it requires less force to move the whole car, so theres more energy for movement itself .

The next part then is the shape of the car. With an aerodynamic design, the air will fow better around the car and will not stop it. doubling speed means 4 times higher air resistance ! So your car needs 4 times more power to pull against air.
so a (bad aerodynamic designed) bodykit can look your car better, but can also slow down or speed up your car at high speeds.

but reducing masses is always good ^^

 

to clarify. F=ma, where F is the amount of 'power' the engine is putting out, m is the mass of the vehicle, and a is the acceleration of the car.

now given the same engine, it will put out the same power, so F is a constant. If you decrease m, then a has to increase to keep F the same. Likewise, if you increase m, then a has to decrease to keep F constant.

 

that's why after high school i study law in college

 

I once heard that every 200lbs is 1/10 of a sec in a 1/4 mi but i'm not sure how accurate that is

 

no. the general rule is 100lbs = 1/10th. see above, 100lbs = .1 seconds. .1 = 1/10th.

 

I just got carried away, it started with a Kicker L5 and turned into 4 amps, 2 batteries, and the way that we are going to do the custom install, how its going to be ported into the cab of the car will be acoustically superior to most cars, consittering the car that I have to start with.