britaxcooper
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Registered: 31st Jan 05
Location: N. yorkshire
User status: Offline
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Just wanting to work out what is needed to have the same power to weight as a certain car, so anyone good at ratios?
car 1) 1344kg and 150bhp
car 2) 850kg and 90bhp or can be 105bhp
basically on paper what weight would have to be lost on car 2 OR what power would be needed for car 2 to have the same power to weight as car 1?
I know gear ratios and aerodynamics come into it but just on paper can someone help me out and say how they did it.
cheers, must be some people with a head on here
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Fraser Young
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Registered: 26th Dec 02
Location: Dundee City Drives: 58 Impreza WRX
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Car 1 is 111 bhp/tonne
Car 2 is 105 bhp/tonne (at 90bhp)
If Car 2 lost 50kg, it would be 112.5bhp/tonne (at 90bhp)
Equally if Car 2 had 96 bhp and stayed 850kg it would be 113bhp/tonne
A combination of both 96bhp and 800kg would be 120bhp/tonne
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Fraser Young
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Registered: 26th Dec 02
Location: Dundee City Drives: 58 Impreza WRX
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Equally if looking for exact figures
To get same power to weight car 2 would have to weigh 806kg OR have 94.9bhp
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britaxcooper
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Registered: 31st Jan 05
Location: N. yorkshire
User status: Offline
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thanks thats great 
how did you work it out then? i guess i really should think about it as im ment to be doing AS maths at college 
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Fraser Young
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Registered: 26th Dec 02
Location: Dundee City Drives: 58 Impreza WRX
User status: Offline
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[Power (in bhp) Divided by weight (in kg)] x1000 to get bhp/tonne
Then you can plug in all but the value you dont have to get the value you need...
e.g. 90bhp/111.6bhp = 0.806 (x1000) = 806kg
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wayne hiscock
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Registered: 20th Jan 01
Location: wiltshire, trowbridge
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in that case that means i got 200bhp/tonne
make me happy
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