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Old Aug 26, 2008 | 09:35 PM
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Default unsprung weight

am i right in thinking that unsprung weight is worth 5x what sprung weight is worth?

so if you remove 1kg from your wheels/brakes thats the same as taking 5kg from inside the car?

now as an average passenger weighs say 80kg, when said passenger gets out of your car you notice the car is quicker,

if you removed 4kg from each corner of unsprung weight, using lighter wheels/brakes
4kgx4 wheels is 16kg total, x5 makes it worth 80kg of sprung weight correct?

would you notice the difference like a passenger got out of the car?

and if you did why do people hit heavy wheels like compomotive MOs?
i have compomotive MO 5 spokes on my car and think i want to change them due to the weight, also my brake setup is quite heavy so would like to lighten that too.

my question is it worth the hassle and expense of changing stuff for a little unsprung weight saving?
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Old Aug 26, 2008 | 09:37 PM
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it wont make the car 5 times lighter weight is weight, fuck all changes there.

but it will make more of a difference to handling than sprung weight would, ie not straight line stuff.

5 times tho i dont know about, doubt there a hard and fast rule regarding that?
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Old Aug 26, 2008 | 09:38 PM
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Not quite

Unsprung weight effects suspension movement - so in reality handling is the reason people and manufactures chase it.

Sprung weight just kills your power to weight ratio - hence its a performance thing.

Alex
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Old Aug 26, 2008 | 09:45 PM
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Unsprung weight will effect handling as said above, it is only dampened by the tyre other than that its free to bounce about. Imagine driving a car with no dampers.

There is no proportion between sprung and unsprung mass in terms of handling, totally dependant on the car, damper etc.

What will effect the effective weight is rotating mass.

This is because you have to make it accelerate in 2 direction (forwards and around).

That is all to do with inertia so again it is not just the weight but the shape of the object.
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Old Aug 26, 2008 | 10:08 PM
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Originally Posted by AlexF
Unsprung weight effects suspension movement
Originally Posted by richard_syko
Unsprung weight will effect handling as said above
affect
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Old Aug 27, 2008 | 07:20 AM
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i know it will help with cornering but i was wondering how different it was to sprung weight to know if you would feel the difference to make it worth the bother
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Old Aug 27, 2008 | 07:24 AM
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If you lost 16Kg from he wheels/brakes etc, then the car would be 16Kg lighter, so it wouldnt be like losing a passenger in terms of better accelleration, but losing unsprung weight is always useful, as mentioned above.

Steve
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Old Aug 27, 2008 | 12:24 PM
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http://dictionary.cambridge.org/defi...4851&dict=CALD
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Old Aug 27, 2008 | 12:26 PM
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Old Aug 27, 2008 | 12:38 PM
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you missed





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Old Aug 27, 2008 | 12:38 PM
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Old Aug 27, 2008 | 03:55 PM
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I didn't feel the need to
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Old Aug 27, 2008 | 04:05 PM
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Originally Posted by stu21t
am i right in thinking that unsprung weight is worth 5x what sprung weight is worth?

so if you remove 1kg from your wheels/brakes thats the same as taking 5kg from inside the car?

now as an average passenger weighs say 80kg, when said passenger gets out of your car you notice the car is quicker,

if you removed 4kg from each corner of unsprung weight, using lighter wheels/brakes
4kgx4 wheels is 16kg total, x5 makes it worth 80kg of sprung weight correct?

would you notice the difference like a passenger got out of the car?

and if you did why do people hit heavy wheels like compomotive MOs?
i have compomotive MO 5 spokes on my car and think i want to change them due to the weight, also my brake setup is quite heavy so would like to lighten that too.

my question is it worth the hassle and expense of changing stuff for a little unsprung weight saving?

This is where the Jap tuning side comes in to its own, How many Ford people ask how heavy a wheel is 0 from what I have seen and over 50% of the Jap cars this is the first thing that is asked,
Rotational weight is a very real benafit not quite what some make out but very real.

Mark
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Old Aug 27, 2008 | 05:39 PM
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Originally Posted by Spiky
you missed
i suggest you take that back, as you are wrong as shown by the common learner error box

http://dictionary.cambridge.org/defi...1392&dict=CALD

Common Learner Error

affect or effect?

Do not confuse the verb affect with the noun effect, which means the result of a particular influence.Global warming is one of the most serious effects of pollution.
sorry to piss on your strawberries with my pedantic ways
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Old Aug 27, 2008 | 06:18 PM
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Originally Posted by Mark Shead
This is where the Jap tuning side comes in to its own, How many Ford people ask how heavy a wheel is 0 from what I have seen and over 50% of the Jap cars this is the first thing that is asked,
Rotational weight is a very real benafit not quite what some make out but very real.

Mark
the reason i got the team dynamics is that they are about the lightest alloy you can get for sensible money! and i did go and pester halfords about if i could feel the wheels before ordering to obtain a guesstimate of relative weights!

Also am looking to have bells made to suit the brembos i have so that i can fit them under 16" wheels and also to reduce the unsprung weight futher..... only way after that would be to have custom hubs :'(

but yeah reducing unsrung weight affects the handling of the car no end!

it also reduces the overall weight of the car and if the rotational parts are replaced for lighter items it reduces the rotational mass and in turn inertia so they can start to rotate with less force needing to be applied (can mean tho that the coefficient of friction between the wheel and tyre is overcome and produces slip - ie lots of wheel spin as the force applied is to great for the amount of grip between the two objects!)
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Old Aug 27, 2008 | 10:39 PM
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Originally Posted by Mark Shead
This is where the Jap tuning side comes in to its own, How many Ford people ask how heavy a wheel is 0 from what I have seen and over 50% of the Jap cars this is the first thing that is asked,
Rotational weight is a very real benafit not quite what some make out but very real.

Mark

this was my question, just how benificial?
the compomotives are very heavy and i was wondering just how much difference lighter wheels and brakes would make.
is it worth the hassle/money????
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