Weight and all that heavy stuff
27-Nov-2003, 02:04 PM
#1
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Thread Starter
Join Date: Jan 2003
Location: on a race track
Posts: 17,846
Weight and all that heavy stuff
Weight and all that heavy stuff
disclamier: neither TCC, it's affiliates, nor the author of this post are to be held responsible for your stupidity. It is YOUR responsibility to make sure you do this in a safe and controlled environment like a PRIVATE place where you have obtained permission to perform any such activities. Misuse of this information can lead to loss of property as well as grave personal injury to both driver and those around him
By gatherer
First let me start by saying I drive a 1993 Honda civic hatchback. This car is in Stock trim and has tons of over steer. Ok I know what you’re saying "this dude is on crack" or how about "someone call the mental instite a patient has escaped". Let me explain why a stock civic has lots of over steer. While yes I will admit I have 0.5 degrees of toe out in the front that is the only change that has been made. The key to the over steer is weight transfer and weight management.
Weight transfer is simple to understand. Simply put it is the shifting of weight or the "load" of the car from 1 of the 4 corners of the car to a different one. What is a corner? Well a corner is one of the 4 wheels. The wheels should be the only part of the car that touches the ground. There are 4 wheels as you know and with a car at rest they all carry part of the load (or weight from now on I use load because it makes more sense to me in the weight management section) When in motion it is possible to have less then 4 wheels contacting the ground. But that’s a part of load management. So weight transfer is the shifting of the load from 1 or more wheels to the others. This is easy to demonstrate.
ACTIVITY 1
To see weight transfer in action, first get into car and start it get out on the side roads and go for a drive. (Please remember that when experiencing this stuff I encourage you to be a safe and responsible driver)
Questions:
1) Accelerate from a stop what happens?
2) From doing the speed limit come to a stop what happens?
3) Make a right hand turn what happens?
4) Make a left hand turn what happens?
*Answers (like in those text books in high school) are at the end of the post*
For a much more extreme test of weight transferring visit an autocross or a solo 2 school. You might not feel brave enough to take your car out there but autocross junkies like me would more then be happy to take you out as a passenger. (We love trying to induce fear.)
Weight Management (a.k.a how to get all the corners to behave themselves.)
Weight management needs to be defined here. I think that’s the best way to start. Weight Management is the process of the driver controlling the transfer of load from one corner to the other corners. "Lovely, so what the hell does that actually mean?" yes I'm sure your saying this now. Best way for me to explain is to lead with an activity.
ACTIVITY 2
Again be safe when trying this activity.
1) In a car on a non busy road take the car to 40km/h first quickly by pressing your foot to the floor and then gently only pushing the accelerator 1/4 of the way to the floor. What happens?
2) From 40km/h try to stop first by pressing the brake quickly to the floor and the second time only gently till the brakes slightly engage. What happens?
REMEMBER TO MAKE SURE NO OTHER CARS ARE AROUND AND THAT YOU’RE IN A SAFE PLACE LIKE AN EMPTY PARKING LOT OR A SIDE STREET 30MINUTES NORTH OF THUNDER BAY. I WILL NOT BE RESPONSIBLE FOR ACCIDENTS
As you can see from these 2 activities in the first test in each step more weight was transferred then in the second test. So it doesn't matter if you’re stopping or accelerating, what matters is the intensity with which you’re doing the task. This is important because it also applies to cornering either to the right or left, it all depends on how intense you make the move.
Intensity and weight transfer. This needs a bit of description because not many people (if anyone) use the word intensity to describe weight transfer. There are limits to everything your car can do before you break traction. You can only corner at a certain G force before your tires let go. You can only accelerate so much before they spin. And you can only break so much before the tires side. This point just before you do break traction is the maximum intensity for all purposes lets call it 100%. You can only ever be at 100% never MORE. So if your taking a corner and using 80% of your traction and then you demand 50% traction for acceleration well that’s a total of 130% and your tires will let go.
I'd go into the traction circle here but that’s scheduled for later on... (Once I find a jpg I can link)
Anyways back to weight management. So the goal of weight management is to shift the load around and yet still keep the tires stuck to the road. So how do we move the load? Simple, apply the brakes and the load moves forward. Push the accelerator and the load moves backwards. Turn left the load goes right turn right the load goes left.
You’re still asking "so where's this magically over steer?"
Weight management skillz y0!
what is over steer and under steer? Both have to do when going around a corner. Over steer is when the back end rotates faster then the front around a corner effectively it makes the car want to take a smaller radius then the actual corner. Over steer is when the front end doesn't turn enough (and the rear end follows the front) effectively this results in the car trying to take a higher radius turn then the corner actually is. so in a front wheel drive car that is designed for the average Joe Schmoe who finds it easier to control under steer and therefore the car has tons of it... how do I get my rear end to step out on command? Well standard race driving for a corner is brake set gas. What does that mean? Brake set gas works like this, approaching the corner on the straight away you brake and slow down for the corner. You get all your braking done before the corner. Then entering the corner you set the steering wheel for the turn. Basically you turn the wheels into the turn. If you do this right and the turn is the same radius throughout the turn you will not have to change the angle of the wheels during the turn. Then as you apex you start applying the gas. See brake set gas. Simple, now for over steer. It’s more brake 1/2 then set then brake then gas. Or something like that it's difficult to explain. But that’s where an autocross helps out.
ACTIVITY 3
Go to an autocross for this
1) When driving at an autocross try out the brake set gas. If you do this right you'll have neutral handling. The idea is to go through the turn without the wheels sliding. If you are still getting tons of under steer when trying this. Then you are not properly doing the braking step. If you get snap overseer or any over steer for that matter then you’re not doing the braking step properly and you’re braking too late.
2) Try applying the brakes later and later try leaving them on after you set the steering wheel. Try braking up to the turn and then releasing the brake, setting the steering wheel and then tapping the brakes again. Your rear end should step out. And over steer should happen. If it's neutral handling check your tire pressures (see tire pressure section) and if it's still under steering you’re going in a little too fast. There is a small window for over steer too fast and you under steer too slow and you have neutral handling through the corner.
Traction Circle
Nice picture but what does it mean? The traction circle helps define that intensity of traction I was speaking about. There are a few things you have to understand. First the scale is in G's or multiples of the force of gravity.
Acceleration and braking are opposites so there fore they go on the same axis. Like wise the left or right turn are opposites and therefore they are on the same axis. The axis' are at 90 degrees from each other because well a left turn or a right turn shifts weight on a 90 angle to acceleration or braking.
The Limit of Adhesion is the maximum grip that the tires can support weather it be 1 g (great tires) or 0.5 g's (crappy tires). The limit of Adhesion is affected by both the tire compound and the road surface. So with the same tires my limit of adhesion would be higher on hot pavement then it would be on cold ice. Temperature affects the surface and affects the tires compound and so it also affects the limit of adhesion.
Current acceleration of the tire. Notice that this arrow isn't directly lined up with any one of the axis' what this means is the tire is current experiencing 2 of the possible 4 events. The tire cannot experience more then 2, it's impossible. So in this picture the tire is both accelerating and performing a right turn.
Sticking and sliding areas. When the current acceleration of the tire is in the area of sticking. When the current acceleration of the tire is in the sliding area guess what it's doing? Sliding.
Each tire has its own traction circle and they are all different. You have 4 different traction circles for one car. When you enter a corner while accelerating, each tire will be accelerating and turning differently. Over steer is when you get the rear tires into the sliding area while keeping the fronts in the sticking area. Under steer is the opposite it's when you get the fronts into the sliding area while the rears remain in the sticking area.
I haven't thought up activities for this section yet.
Static Weight balance
This is also called corner weighing. Seriously I could talk lots about this section. But I do not have co lovers so I have no practically experience. So let’s call on the experts.
incase the window doesn't display:
http://www.ground-control.com/?D=e04...ffa901ba6b5aaa
*edit* window did not display
That ground control article specifies how to control weigh but not why. We corner weigh a car when co lovers are put on to balance the car in a static (at rest) state. What this will do is have the same front to rear weight ratio on the left side of the car as it is on the right side. This results in easier weight management.
Weight reduction and how does it help.
Well it helps if it's done right and hinders if it's done wrong. Reducing the weight of a vehicle helps the acceleration the braking and cornering it's one of the best moods you could do. Or is it? See a stock car is weight balanced. Yes the total right side or left side will be heavier then the other. But by design the ratio of weight on the front right tire compared with the weight of the right rear tire will be the same as the ratio of the weight on the front left tire and the weight on the rear left tire. The ratios are the same the actual weights probably aren’t. Reducing weight is great but it does change these ratios so it has to be done careful throw the ratios too far out of balance and your car will handle like crap ... acceleration and braking will not be straight as well. But as long as it's done carefully your fine. So if you replace the rebar in the front bumper with a lighter bar and then do the same to the rear you haven't really changed the ratios that much if at all. Also removing the headliner helps out 2 fold. First for the reasons I gave before and second it lowers the center of gravity. Lowered centers of gravity help out a lot and bbarbulo will probably go into detail about what it is.
Ok I think that’s all I have to say about weight and everything that's heavy.
I'll create more tech articles later on bbarbulo this is dedicated to you and encouraging me to type SO FRIGGIN MUCH
Answers
ACTIVITY 1
Questions:
1) Accelerate from a stop what happens?
The weight is transferred from the front wheels to the rear
2) From doing the speed limit come to a stop what happens?
The weight is transferred from the rear wheels to the front
3) Make a right hand turn what happens?
The weight is transferred from the inside (right) wheels to the outside (left) wheels
4) Make a left hand turn what happens?
The weight is transferred from the inside (left) wheels to the outside (right) wheels
ACTIVITY 2
1) In a car on a non busy road take the car to 40km/h first quickly by pressing your foot to the floor and then gently only pushing the accelerator 1/4 of the way to the floor. What happens?
The Car will transfer more weight to the rear the harder the accelerator is pressed
2) From 40km/h try to stop first by pressing the brake quickly to the floor and the second time only gently till the brakes slightly engage. What happens?
The car moves more weight to the front the harder the brake is pressed.
disclamier: neither TCC, it's affiliates, nor the author of this post are to be held responsible for your stupidity. It is YOUR responsibility to make sure you do this in a safe and controlled environment like a PRIVATE place where you have obtained permission to perform any such activities. Misuse of this information can lead to loss of property as well as grave personal injury to both driver and those around him
By gatherer
First let me start by saying I drive a 1993 Honda civic hatchback. This car is in Stock trim and has tons of over steer. Ok I know what you’re saying "this dude is on crack" or how about "someone call the mental instite a patient has escaped". Let me explain why a stock civic has lots of over steer. While yes I will admit I have 0.5 degrees of toe out in the front that is the only change that has been made. The key to the over steer is weight transfer and weight management.
Weight transfer is simple to understand. Simply put it is the shifting of weight or the "load" of the car from 1 of the 4 corners of the car to a different one. What is a corner? Well a corner is one of the 4 wheels. The wheels should be the only part of the car that touches the ground. There are 4 wheels as you know and with a car at rest they all carry part of the load (or weight from now on I use load because it makes more sense to me in the weight management section) When in motion it is possible to have less then 4 wheels contacting the ground. But that’s a part of load management. So weight transfer is the shifting of the load from 1 or more wheels to the others. This is easy to demonstrate.
ACTIVITY 1
To see weight transfer in action, first get into car and start it get out on the side roads and go for a drive. (Please remember that when experiencing this stuff I encourage you to be a safe and responsible driver)
Questions:
1) Accelerate from a stop what happens?
2) From doing the speed limit come to a stop what happens?
3) Make a right hand turn what happens?
4) Make a left hand turn what happens?
*Answers (like in those text books in high school) are at the end of the post*
For a much more extreme test of weight transferring visit an autocross or a solo 2 school. You might not feel brave enough to take your car out there but autocross junkies like me would more then be happy to take you out as a passenger. (We love trying to induce fear.)
Weight Management (a.k.a how to get all the corners to behave themselves.)
Weight management needs to be defined here. I think that’s the best way to start. Weight Management is the process of the driver controlling the transfer of load from one corner to the other corners. "Lovely, so what the hell does that actually mean?" yes I'm sure your saying this now. Best way for me to explain is to lead with an activity.
ACTIVITY 2
Again be safe when trying this activity.
1) In a car on a non busy road take the car to 40km/h first quickly by pressing your foot to the floor and then gently only pushing the accelerator 1/4 of the way to the floor. What happens?
2) From 40km/h try to stop first by pressing the brake quickly to the floor and the second time only gently till the brakes slightly engage. What happens?
REMEMBER TO MAKE SURE NO OTHER CARS ARE AROUND AND THAT YOU’RE IN A SAFE PLACE LIKE AN EMPTY PARKING LOT OR A SIDE STREET 30MINUTES NORTH OF THUNDER BAY. I WILL NOT BE RESPONSIBLE FOR ACCIDENTS
As you can see from these 2 activities in the first test in each step more weight was transferred then in the second test. So it doesn't matter if you’re stopping or accelerating, what matters is the intensity with which you’re doing the task. This is important because it also applies to cornering either to the right or left, it all depends on how intense you make the move.
Intensity and weight transfer. This needs a bit of description because not many people (if anyone) use the word intensity to describe weight transfer. There are limits to everything your car can do before you break traction. You can only corner at a certain G force before your tires let go. You can only accelerate so much before they spin. And you can only break so much before the tires side. This point just before you do break traction is the maximum intensity for all purposes lets call it 100%. You can only ever be at 100% never MORE. So if your taking a corner and using 80% of your traction and then you demand 50% traction for acceleration well that’s a total of 130% and your tires will let go.
I'd go into the traction circle here but that’s scheduled for later on... (Once I find a jpg I can link)
Anyways back to weight management. So the goal of weight management is to shift the load around and yet still keep the tires stuck to the road. So how do we move the load? Simple, apply the brakes and the load moves forward. Push the accelerator and the load moves backwards. Turn left the load goes right turn right the load goes left.
You’re still asking "so where's this magically over steer?"
Weight management skillz y0!
what is over steer and under steer? Both have to do when going around a corner. Over steer is when the back end rotates faster then the front around a corner effectively it makes the car want to take a smaller radius then the actual corner. Over steer is when the front end doesn't turn enough (and the rear end follows the front) effectively this results in the car trying to take a higher radius turn then the corner actually is. so in a front wheel drive car that is designed for the average Joe Schmoe who finds it easier to control under steer and therefore the car has tons of it... how do I get my rear end to step out on command? Well standard race driving for a corner is brake set gas. What does that mean? Brake set gas works like this, approaching the corner on the straight away you brake and slow down for the corner. You get all your braking done before the corner. Then entering the corner you set the steering wheel for the turn. Basically you turn the wheels into the turn. If you do this right and the turn is the same radius throughout the turn you will not have to change the angle of the wheels during the turn. Then as you apex you start applying the gas. See brake set gas. Simple, now for over steer. It’s more brake 1/2 then set then brake then gas. Or something like that it's difficult to explain. But that’s where an autocross helps out.ACTIVITY 3
Go to an autocross for this
1) When driving at an autocross try out the brake set gas. If you do this right you'll have neutral handling. The idea is to go through the turn without the wheels sliding. If you are still getting tons of under steer when trying this. Then you are not properly doing the braking step. If you get snap overseer or any over steer for that matter then you’re not doing the braking step properly and you’re braking too late.
2) Try applying the brakes later and later try leaving them on after you set the steering wheel. Try braking up to the turn and then releasing the brake, setting the steering wheel and then tapping the brakes again. Your rear end should step out. And over steer should happen. If it's neutral handling check your tire pressures (see tire pressure section) and if it's still under steering you’re going in a little too fast. There is a small window for over steer too fast and you under steer too slow and you have neutral handling through the corner.
Traction Circle
Nice picture but what does it mean? The traction circle helps define that intensity of traction I was speaking about. There are a few things you have to understand. First the scale is in G's or multiples of the force of gravity.
Acceleration and braking are opposites so there fore they go on the same axis. Like wise the left or right turn are opposites and therefore they are on the same axis. The axis' are at 90 degrees from each other because well a left turn or a right turn shifts weight on a 90 angle to acceleration or braking.
The Limit of Adhesion is the maximum grip that the tires can support weather it be 1 g (great tires) or 0.5 g's (crappy tires). The limit of Adhesion is affected by both the tire compound and the road surface. So with the same tires my limit of adhesion would be higher on hot pavement then it would be on cold ice. Temperature affects the surface and affects the tires compound and so it also affects the limit of adhesion.
Current acceleration of the tire. Notice that this arrow isn't directly lined up with any one of the axis' what this means is the tire is current experiencing 2 of the possible 4 events. The tire cannot experience more then 2, it's impossible. So in this picture the tire is both accelerating and performing a right turn.
Sticking and sliding areas. When the current acceleration of the tire is in the area of sticking. When the current acceleration of the tire is in the sliding area guess what it's doing? Sliding.
Each tire has its own traction circle and they are all different. You have 4 different traction circles for one car. When you enter a corner while accelerating, each tire will be accelerating and turning differently. Over steer is when you get the rear tires into the sliding area while keeping the fronts in the sticking area. Under steer is the opposite it's when you get the fronts into the sliding area while the rears remain in the sticking area.
I haven't thought up activities for this section yet.
Static Weight balance
This is also called corner weighing. Seriously I could talk lots about this section. But I do not have co lovers so I have no practically experience. So let’s call on the experts.
incase the window doesn't display:
http://www.ground-control.com/?D=e04...ffa901ba6b5aaa
*edit* window did not display
That ground control article specifies how to control weigh but not why. We corner weigh a car when co lovers are put on to balance the car in a static (at rest) state. What this will do is have the same front to rear weight ratio on the left side of the car as it is on the right side. This results in easier weight management.
Weight reduction and how does it help.
Well it helps if it's done right and hinders if it's done wrong. Reducing the weight of a vehicle helps the acceleration the braking and cornering it's one of the best moods you could do. Or is it? See a stock car is weight balanced. Yes the total right side or left side will be heavier then the other. But by design the ratio of weight on the front right tire compared with the weight of the right rear tire will be the same as the ratio of the weight on the front left tire and the weight on the rear left tire. The ratios are the same the actual weights probably aren’t. Reducing weight is great but it does change these ratios so it has to be done careful throw the ratios too far out of balance and your car will handle like crap ... acceleration and braking will not be straight as well. But as long as it's done carefully your fine. So if you replace the rebar in the front bumper with a lighter bar and then do the same to the rear you haven't really changed the ratios that much if at all. Also removing the headliner helps out 2 fold. First for the reasons I gave before and second it lowers the center of gravity. Lowered centers of gravity help out a lot and bbarbulo will probably go into detail about what it is.
Ok I think that’s all I have to say about weight and everything that's heavy.
I'll create more tech articles later on bbarbulo this is dedicated to you and encouraging me to type SO FRIGGIN MUCH
Answers
ACTIVITY 1
Questions:
1) Accelerate from a stop what happens?
The weight is transferred from the front wheels to the rear
2) From doing the speed limit come to a stop what happens?
The weight is transferred from the rear wheels to the front
3) Make a right hand turn what happens?
The weight is transferred from the inside (right) wheels to the outside (left) wheels
4) Make a left hand turn what happens?
The weight is transferred from the inside (left) wheels to the outside (right) wheels
ACTIVITY 2
1) In a car on a non busy road take the car to 40km/h first quickly by pressing your foot to the floor and then gently only pushing the accelerator 1/4 of the way to the floor. What happens?
The Car will transfer more weight to the rear the harder the accelerator is pressed
2) From 40km/h try to stop first by pressing the brake quickly to the floor and the second time only gently till the brakes slightly engage. What happens?
The car moves more weight to the front the harder the brake is pressed.
28-Nov-2003, 12:08 PM
#3
Just to sum it all up.... kinda like a "For Dummies" series...
basically how your car handles will depend on the weight transfer management. whether you change the weight transfer by changing your driving technique or by swapping parts... that's up to you and the class rules for the class you are racing in.
it is also worth mentioning that if you pay close attention to the circle of traction, you'll notice if you are doing TWO things at the same time (ie. turning AND braking) the G force that you effectively have to play with is reduced for both activities. For example, say for example, under braking only you can exert 1G of braking force.... and under turning only you can exert 1G of turning force... well combine the two and you can only do say 0.5g's turning and 0.75g's braking... you ask for more braking than 0.75g's and you are outside of the traction circle which sends you into a tractionless situation. Also, it's worth mentioning that the traction circle is in fact NOT a circle... actually, it's not at all a regular shape. The car is NOT square (wheelbase length x width) and static weight distribution is NOT 50/50 in a Civic, and most Civics have an open diff which also affects the traction circle. So keep that in mind.
gatherer, I'm really impressed with your article... I'm inspired to do an article on CG and roll center... and prolly some engine articles too. Do you want to write about chassis rigidity and dynamics... seam welding, roll cages, strut bars, lower braces, and also one on tire compounds and tread choice for winter, daily, and performance conditions?
basically how your car handles will depend on the weight transfer management. whether you change the weight transfer by changing your driving technique or by swapping parts... that's up to you and the class rules for the class you are racing in.
it is also worth mentioning that if you pay close attention to the circle of traction, you'll notice if you are doing TWO things at the same time (ie. turning AND braking) the G force that you effectively have to play with is reduced for both activities. For example, say for example, under braking only you can exert 1G of braking force.... and under turning only you can exert 1G of turning force... well combine the two and you can only do say 0.5g's turning and 0.75g's braking... you ask for more braking than 0.75g's and you are outside of the traction circle which sends you into a tractionless situation. Also, it's worth mentioning that the traction circle is in fact NOT a circle... actually, it's not at all a regular shape. The car is NOT square (wheelbase length x width) and static weight distribution is NOT 50/50 in a Civic, and most Civics have an open diff which also affects the traction circle. So keep that in mind.
gatherer, I'm really impressed with your article... I'm inspired to do an article on CG and roll center... and prolly some engine articles too. Do you want to write about chassis rigidity and dynamics... seam welding, roll cages, strut bars, lower braces, and also one on tire compounds and tread choice for winter, daily, and performance conditions?
04-Dec-2003, 10:48 PM
#6
Registered User
Thread Starter
Join Date: Jan 2003
Location: on a race track
Posts: 17,846
Corner Wieghing .. By me..
Check out www.ground-control.com for a great read on the how's and why's of this.
you wiegh all four corners of your car (a corner in this case is the wheels) you place them on scales....
now you add the front and back together for the left side and the front and back together for the right side. these are you total wieghts no matter how hard you try the wieght on the left side will not decrease on increase and same with the wieght on the right side.
now you work out the front left as a percent of the total left side wieght..... you do the same for for the right side and backs of both sides....
so the calculation to use is:
Where LF is Left Front wieght
Where LR is Left Rear wieght
Where RF is right Front wieght
Where RR is Right rear wieght
LF/(LF +LR) *100% = Left Front percentage of Left Side (LFP)
LR/(LF +LR) *100% = Left Rear percentage of Left Side (LRP)
RF/(RF +RR) *100% = Right Front percentage of Right Side (RFP)
RR/(RF +RR) *100% = Right Rear percentage of Right Side (RRP)
the Goal of corner wieghting is to get LFP=RFP and LRP=RRP, these are the percentages you want to make equal so even if the total Right side is heavier then the total left side the ratio of front to back wieght is the same. in Weight distribution it's all about ratios not actual wieght.
now to adjust the wieght on each corner like was said before you raidse and lower the spring perches. I recommend starting at the drop you want and then going from there.
key things to remember:
1) trial and error is ok. if you have the scales or a certain amount of time with them experiment thats how you learn you can't break anything.
2) Corner Weigh the car with Driver and any normal Passengers.... if you drive Grandma to work everyday have Grandma come out for the day ... you spend time with her (which she'll like) you at her cookies (which She'll like) and your driving her around all the time will be a nice smooth ride (Which she'll like)
3) if you raise a corner of the car that corner will have MORE weight on it not less (confusing ain't it? I'll explain later
4) if you change something on one corner it will afffect the wieght at all corners. However the second most affected corner will be the one opposite the one your working on. quick way to find the opposite one. take whichever side your working on and take the opposite of that now take the position your working on(front or back) now take the opposite of that. and presto the opposite corner emerges. so if you change the LF the RR will be the next most affected corner.
Number 4 there is important because when you move wieght around it's easy to see (after doing step one a bit) that wieght for the most part is moved from one corner to the opposite corner.
now stolen directly from a book I own:
ok so now you have it. once you have the LFP = the RFP and the RRP= the LRP your car is properly corner wieghted.
I think I'm going to place this in a special spot as well....
Check out www.ground-control.com for a great read on the how's and why's of this.
you wiegh all four corners of your car (a corner in this case is the wheels) you place them on scales....
now you add the front and back together for the left side and the front and back together for the right side. these are you total wieghts no matter how hard you try the wieght on the left side will not decrease on increase and same with the wieght on the right side.
now you work out the front left as a percent of the total left side wieght..... you do the same for for the right side and backs of both sides....
so the calculation to use is:
Where LF is Left Front wieght
Where LR is Left Rear wieght
Where RF is right Front wieght
Where RR is Right rear wieght
LF/(LF +LR) *100% = Left Front percentage of Left Side (LFP)
LR/(LF +LR) *100% = Left Rear percentage of Left Side (LRP)
RF/(RF +RR) *100% = Right Front percentage of Right Side (RFP)
RR/(RF +RR) *100% = Right Rear percentage of Right Side (RRP)
the Goal of corner wieghting is to get LFP=RFP and LRP=RRP, these are the percentages you want to make equal so even if the total Right side is heavier then the total left side the ratio of front to back wieght is the same. in Weight distribution it's all about ratios not actual wieght.
now to adjust the wieght on each corner like was said before you raidse and lower the spring perches. I recommend starting at the drop you want and then going from there.
key things to remember:
1) trial and error is ok. if you have the scales or a certain amount of time with them experiment thats how you learn you can't break anything.
2) Corner Weigh the car with Driver and any normal Passengers.... if you drive Grandma to work everyday have Grandma come out for the day ... you spend time with her (which she'll like) you at her cookies (which She'll like) and your driving her around all the time will be a nice smooth ride (Which she'll like)
3) if you raise a corner of the car that corner will have MORE weight on it not less (confusing ain't it? I'll explain later
4) if you change something on one corner it will afffect the wieght at all corners. However the second most affected corner will be the one opposite the one your working on. quick way to find the opposite one. take whichever side your working on and take the opposite of that now take the position your working on(front or back) now take the opposite of that. and presto the opposite corner emerges. so if you change the LF the RR will be the next most affected corner.
Number 4 there is important because when you move wieght around it's easy to see (after doing step one a bit) that wieght for the most part is moved from one corner to the opposite corner.
now stolen directly from a book I own:
The Second Principle is that raising a corner will make it heavier. Does that make Sense? It Does if you think about it in terms of what is happening to the wheel. You're not raising the car as much as you are pushing the wheel down towards the ground. Mark at Carrera gave me a very easy principle: lower is lighter
I think I'm going to place this in a special spot as well....
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