weight question?

[emery1990]

how much weight do you think would need to be lost to get a one second faster 0-60mph .

 

[Sid447]

That would depend on the power,

a car would have.
Power to weight is always the initial equation.
But not the only way.
Changing a cars diff gearing can do much the same without altering weight or power.

As a rough rule of thumb though, every 10kgs is worth 2hp.

 

[emery1990]

so 100kg would result in a 20bhp increase.

i know the gearing would make the difference, but just on the gearing it is in and doing no ther modifactions just weight loss. i took my spare whell out weighing around 20kg, so i would get a 4 hp increase.

 

[nig]

so 100kg would result in a 20bhp increase.

i know the gearing would make the difference, but just on the gearing it is in and doing no ther modifactions just weight loss. i took my spare whell out weighing around 20kg, so i would get a 4 hp increase.

cool lost 130kg's + so far, that would give me 26hp tyer well will come out this week

 

[HDi fun]

It's common for true supercars (500bhp plus) to be geared so that they can just reach 62mph in first. This, of course means that the clutch gets a battering getting it away at 8000+ rpm. So do the tyres. THey act like substitutes for an hydraulic torque converter.

The gearchange thus avoided gives a better 0-62 time that would be achieved if there was a need to snatch 2nd on the way.

0-62 is a benchmark, and it's well known. But it doesn't tell the whole story. What I like to see is 60-85 (60 times sqrt 2) being the same as 0-60. That's a better measure.

Weight reduction works across the whole performance envelope of a car. It's worth doing if you really want every last ounce of performance. Air resistance is negligible at low speed.

 

[old-git]

That would depend on the power,

a car would have.
Power to weight is always the initial equation.
But not the only way.
Changing a cars diff gearing can do much the same without altering weight or power.

As a rough rule of thumb though, every 10kgs is worth 2hp.

Depends on your starting position. A 300bhp 2 ton Yank Tank will hardly notice 100Kg, but take that off of a 300bhp Caterham Superlight....

Power to weight is my obsession. At 550bhp and 600kg, each Kg is worth almost 1bhp/tonne.

Just run an experiement on my Cartest 2000 simulation sotfware. Using a Nissan 200SX Turbo weighing 2450lbs, the 0-60 is 6.67. To get this down to 5.67 you will have to shed 550lbs! Increasing the bhp and torque (both 180) by 50 achieved the same result, roughly ageeing with Sid's 10kg/2bhp.

 

[obi_waynne]

Have a play with this http://www.torquecars.com/tools/quarter-mile-time.php it will give you an idea of the role weight and power takes.

 

[emery1990]

I would need a remap to 210 bhp then loose 100kg to gain a second.

 

[old-git]

I would need a remap to 210 bhp then loose 100kg to gain a second.

The remap is the easy bit

 

[emery1990]

ha yer sure is, how much lighter would the exact same seats be in my car, but non electric, i presume you can probally get these in the lower spec versions. as i dunt really use it that much and i can buy a back support anyway.

 

[HDi fun]

Quite a lot lighter. I've got electric seats in the front (8 way adjusting for driver and passenger). THey've got to weigh in at a few dozen kilograms over manual ones - DC motors are HEAVY