power:weight

[howie p]

what kinda of p2w ratio can be achieved with a mk2 172

arent the 155 standard?

how much weight can u lose easily, does it feel any different once lost?

(never driven a cup either)

 

[dannyboy172]

I remember on top gear, when they had the 182 cup on, that the power to weight ratio was stated at roughly 169bhp per tonne...same as the lotus elise, if i'm not mistaken? If thats anything to go by the 172's must be near 165ish?

 

[Neil82]

Mark 2 172 has a 155 p/w/r (if its got 172 hp)

 

[thedoc]

easiest thing to do is ditch the spare wheel & tool kit, thats about 20kg..

 

[Scoobywhoo]

Just something for you to consider:-

If you double the weight in a car then you need to quadroople (spelling!) the power to achieve the same acceleration. That gives you an idea of how important saving weight is with regards to acceleration anyway !!

 

[lee_cup]

think i better loose some weight then, or get a turbo to even it out

 

[GordonD]

Just something for you to consider:-

If you double the weight in a car then you need to quadroople (spelling!) the power to achieve the same acceleration. That gives you an idea of how important saving weight is with regards to acceleration anyway !!

Utter rubbish.

Total nonsense.

Double the weight and the power and you'll get exactly the same acceleration.

You may be confused with speed and braking, where doubling the speed quadruples the distance it takes to stop. Acceleration/deceleration to distance is a square rule.

Or with top speed where it takes 8 times as much power to go twice as fast. Air resistance is a cube rule.

Or with quarter mile time where its takes 16 times as much power (or a weight reduction by a factor of 18) to do half the quarter mile time. The relationship between power-to-weight, time and distance is a fourth power rule.

 

[howie p]

interestin^ where does every1 get to know stuff like this, physics at uni of something?

 

[Phill1978]

just geeks

 

[Dave.]

171 per tonne over here

 

[Scoobywhoo]

Utter rubbish.

Total nonsense.

Double the weight and the power and you'll get exactly the same acceleration.

You may be confused with speed and braking, where doubling the speed quadruples the distance it takes to stop. Acceleration/deceleration to distance is a square rule.

Or with top speed where it takes 8 times as much power to go twice as fast. Air resistance is a cube rule.

Or with quarter mile time where its takes 16 times as much power (or a weight reduction by a factor of 18) to do half the quarter mile time. The relationship between power-to-weight, time and distance is a fourth power rule.

Many moons ago when doing similar calculations - i'm seem to remember (could be wrong) that to do a 1/4 mile in the same time with double the weight you would need 4 times the power. i can't remember the formulas now i don't use them any more. So then does this apply ?? You could well be correct - i thought this was a general rule of thumb ?? Haven't done this for years !!