se7ensport
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| posted on 10/4/07 at 02:41 PM |
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Corner weighting calculation required
I've lost the link I had which gave a good explaination, anyone got one?
Thanks
Alex
Ps I tried a search but without any luck
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GeoffT
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| posted on 10/4/07 at 03:10 PM |
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My method? Dead simple: Initially rough adjust for required ride height, then using cornerweight scales, fine adjust so that each diagonal pair of
wheels is carrying an equal amount of weight.
That's it. Doesn't matter whether the tank is full or empty, or who is or isn't sitting in the car, this still holds true
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Mal
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| posted on 10/4/07 at 03:35 PM |
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Clarification of Terminology
When you say weight on diagonal wheels: do you mean equalising the weight on the opposite side of the same axle, ie, front wheels OR say, the front
right wheel equalised with the left rear?
Mal.
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Mal
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| posted on 10/4/07 at 03:35 PM |
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Clarification of Terminology
When you say weight on diagonal wheels: do you mean equalising the weight on the opposite side of the same axle, ie, front wheels OR say, the front
right wheel equalised with the left rear?
Mal.
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Mal
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| posted on 10/4/07 at 03:37 PM |
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Reminder to me!
Don't press the post reply button twice.
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se7ensport
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| posted on 10/4/07 at 03:42 PM |
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I think* it is the sum of the front left + rear right is equal to front right + rear left.
Alex
* I'm not 100%, hence the quesion
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GeoffT
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| posted on 10/4/07 at 03:52 PM |
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Sorry, my explanation was a bit ambiguous - it's as sevensport has just clarified.
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se7ensport
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| posted on 10/4/07 at 04:01 PM |
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Thanks Geoff, found this between replies: Spreadsheet
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higgsti
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| posted on 10/4/07 at 04:28 PM |
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corner weights should be done with the driver in the car or at least ballast to the drivers weight otherwise your altering everything youve done when
you sit in it .11stone driver or 70ish kilos completley mucks everything up unless you have a similiar weight passenger in the car
[Edited on 10/4/07 by higgsti]
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GeoffT
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| posted on 10/4/07 at 04:57 PM |
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quote:
corner weights should be done with the driver in the car or at least ballast to the drivers weight otherwise your altering everything youve done when
you sit in it .11stone driver or 70ish kilos completley mucks everything up unless you have a similiar weight passenger in the car
Sorry, but I disagree - the weight of the driver (or passenger, it doesn't matter) will always be distributed around the four wheels in a manner
that maintains the diagonal equilibrium. It's a concept that I can picture in my head, but don't know how to express mathematically, any
takers...?
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higgsti
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| posted on 10/4/07 at 05:18 PM |
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how can a vehicle with more weight on one corner ie driver be balanced .race teams spend hrs moving things around there cars to achieve a balanced car
like batteries fuel tanks .why do raceline make a special bell housing adapter for a duratec to type nine in order to fit the engine closer to the
back .everybody i know who has had a car corner weighted has always been asked there weight so the car can be balanced accordingly.if all this doesnt
matter how come i can notice adifference in a corner when i have a passenger in
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GeoffT
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| posted on 10/4/07 at 05:49 PM |
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In cornerweight terms, the only thing you can really adjust with spring platforms is that the two diagonals carry their equal share of the weight.
Adding weight in one corner will obviously increase the weight on that wheel, but the sum weights of the two diagonals will still be the same...
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higgsti
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| posted on 10/4/07 at 05:58 PM |
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http://www.ybapublications.co.uk/shortcircuit/Features/sc_story_weight_distribution.htm
quote
Taking readings accurately is a two-man job as the driver will be in the car when it is on the track, he needs to be in the car to get the proper
readings, plus anything else as if the car was on track ready for the race.
http://www.northamptonmotorsport.com/default.asp?id=20
quote
your car has adjustable spring platform shock absorbers, the platforms can be adjusted up or down to optimise the distribution of weight around the
car, this allows us to take into account the manufacturing tolerances in the suspension and chassis and also to compensate for driver weight. Corner
weighting can also be useful during the build of a car as once the major items whose position is fixed have been fitted other items such as batteries,
fire extinguishers etc can be placed to optimise the weight distribution as much as possible.
another quote
We adjust the cornerweights to give the best balance between cornering and braking taking into account fuel load and driver weight. A properly
adjusted car will corner harder, have more steering feel and be more stable under braking with a reduction in the tendency to lock one wheel under
hard braking.
http://www.stockcarcentral.co.uk/tech_tips/corner_weights.htm
thats 4 websites which say your talking rubbish
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higgsti
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| posted on 10/4/07 at 06:12 PM |
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In cornerweight terms, the only thing you can really adjust with spring platforms is that the two diagonals carry their equal share of the weight.
Adding weight in one corner will obviously increase the weight on that wheel, but the sum weights of the two diagonals will still be the same...
how can they be as soon as you sit in the drivers seat youve altered one of your diagonals and also your rear end balance left to right.why bother
cornerweight the car if what your saying you might as well just weigh front axle get these the same then do the same at back axle and front to back
not bother with the diagonals
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britishtrident
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| posted on 10/4/07 at 06:14 PM |
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Anti roll bar(s) if fitted should be disconnected and reconnected and adjusted after adjustment of corner heights
Driver MUST be in car.
The aim is to get each corner bearing the weight it should according to the fore-aft and left-right weight distribution.
Setting both front corners to equal weights is the wrong way to do it, it will cost dearly in terms of traction.
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GeoffT
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| posted on 10/4/07 at 06:16 PM |
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Higgsti,
If you look under the "crossweight" section of the first link in your post, you'll find precisely the concept I've been
discussing - albeit maybe a little better explained.......
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britishtrident
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| posted on 10/4/07 at 06:21 PM |
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quote:
Originally posted by GeoffT
Sorry, but I disagree - the weight of the driver (or passenger, it doesn't matter) will always be distributed around the four wheels in a manner
that maintains the diagonal equilibrium. It's a concept that I can picture in my head, but don't know how to express mathematically, any
takers...?
Corner weights and ride height are interdependent and have to be set at the same time, if the driver and other loads such as fuel aren't in
the car any corner adjustment is a waste of time.
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higgsti
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| posted on 10/4/07 at 06:21 PM |
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from same website in the how to section it states
quote
Taking readings accurately is a two-man job as the driver will be in the car when it is on the track, he needs to be in the car to get the proper
readings, plus anything else as if the car was on track ready for the race.
the driver must be in the car or ballast of his weight
[Edited on 10/4/07 by higgsti]
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GeoffT
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| posted on 10/4/07 at 06:37 PM |
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.....but I maintain you'll end up with the same crossweight adjustment whether the driver is in the car or not. To quote from further down the
section you mention :-
"......and most importantly the crossweight. This is the combined percentage of the outside front wheel and the inner rear wheel."
I can accept that in something like small oval racing where cars only corner in one direction, then crossweight maladjustment may have some advantage,
but I can't see any advantage in it for road vehicles
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higgsti
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| posted on 10/4/07 at 06:45 PM |
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your car has adjustable spring platform shock absorbers, the platforms can be adjusted up or down to optimise the distribution of weight around the
car, this allows us to take into account the manufacturing tolerances in the suspension and chassis and also to compensate for driver weight. Corner
weighting can also be useful during the build of a car as once the major items whose position is fixed have been fitted other items such as batteries,
fire extinguishers etc can be placed to optimise the weight distribution as much as possible.
from northhampton motorsport .it matters more on cars which are driven in different directions if its important to move a battery round a car and fire
extinguiser im sure an 11 stone plus drivers weight is
[Edited on 10/4/07 by higgsti]
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GeoffT
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| posted on 10/4/07 at 07:04 PM |
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....ok, we'll obviously have to agree to disagree....., interesting discussion though.
....but next time you get a chance to set up corner weights calculate and set up equal crossweights with an empty car, put somebody in the
driver's seat and recalculate the crossweights. You may get a surprise and find that you don't need to readjust......
ATB, Geoff.
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higgsti
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| posted on 10/4/07 at 08:16 PM |
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and why dont you try putting ballast in your car to your weight on your side and post up your findings on here
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JoelP
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| posted on 10/4/07 at 08:33 PM |
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i think geoff is right mathmatically, after all if a 100kgs driver sits over the back right wheel, he would add roughly 50 kgs to that wheel and 25kgs
to each of the wheels on the other diagonal. So, totals would be unchanged. However, you are also totally correct that the driver should be in, as the
ride height would end up uneven.
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higgsti
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| posted on 10/4/07 at 08:37 PM |
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http://7faq.com/owbase/ow.asp?FlatFloorSetup
another one for you geoff in the set up it says and relevent to our cars
Second all weights should be taken with the driver in the car and with an average load of fuel.
all these people cant be wrong unless its a conspiracy theory.you can learn something every day
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higgsti
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| posted on 10/4/07 at 08:51 PM |
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maybee the maths is right but were talking about the correct way to corner weight a car
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