Suspension Corner Balancing
Corner Balancing
I am taking the plunge and going with Bilstein PSS9 Coilovers. I have heard of corner balancing but know nothing of what it is. Is this a pre-loading of the suspension? Any help would be great.
wooo... another long thread coming. 
k9mini- yes, it is preloading the coilovers until each corner has its ideal
weight distribution so the car sits flat horizontally and with watever
rake you want forward/aft to dial-in your car's dynamics. it's quite
involved and I think Dr.Meb is typing away as we speak for a very
thoruoughghghghh, explanation.
k9mini- yes, it is preloading the coilovers until each corner has its ideal
weight distribution so the car sits flat horizontally and with watever
rake you want forward/aft to dial-in your car's dynamics. it's quite
involved and I think Dr.Meb is typing away as we speak for a very
thoruoughghghghh, explanation.
3rd Gear
Joined: Jan 2005
Posts: 175
Likes: 0
From: Near Charlotte, NC
I'm not "Dr. Meb" or Onasled, and haven't done this in a few years, so please don't flame me if I get a detail wrong here or there - I am only trying to help.
It involves using a set of car scales that have four scale pads - one to be placed under each wheel, that are joined to a common console that shows the weight supported by each independent wheel. It can show (diagonal) cross-weight, or the sum of any combination or ALL of the individual weights. This is the same type of scales used in impound at SCCA Nationals, National Tours, ProSolos, etc.. But the better performance alignment shops have them and/or you can buy a set from RacerWholesale and other race shops. This process needs to be done on a perfectly level and even surface to ensure accuracy.
In its simplest form, your intent is to use these scales to balance the car's weight Diagonally (LF to RR, RF to LR), Front to Back and Left to Right as accurately as is practical. You do this by adjusting the ride height of each shock individually while watching the weights move around. As you lower one corner, you are essentially 'Tilting' the car towards that corner, thereby INCREASING the percentage of static load (weight) that corner carries.
You start by setting each coilover's ride height so the car is even and level, with the basic amount of drop from stock that you want. Measure the arch height-to-ground on each wheel well, adjust each shock until the car is level, then establish the rake that you want (if any). Make sure the suspension does not have a chance to bottom-out due to lack of travel, because if you set it too low, it will hit or ride on the bump-stops and induce what is called bump steer, a dangerous condition that could cause you to lose control. Run-in the new springs with this basic configuration locked down for a bit before messing with the scales to make sure they are fully seated and settled-in.
Then, when you put the car on the scales, make sure the suspension is loaded like normal (and can move freely - not in any bind) and plan for a few hours of tweaking...
Obviously, given the front-heavy weight bias of the MINI, there is just so much you can do to level the weight F-to-R by changing the ride height of coilovers. But, you can still send a little weight to the back without making the front all jacked-up and the rear scrape the ground (in other words, use some common sense with your settings).
To do cross-weight comparisons, set the scale controller to display one front and one rear (the rear opposite side as the front, as shown below) and adjust each corner's ride height so that the LF+RR pair supports the EXACT same percentage of weight as the RF+LR pair WITH the driver sitting in the driver seat just as the car would be driven. 50% is ideal, of course.
LF . . . . . . RF RF+LR=50%
. .\ . . . . . /
. . .\ . . . /
. . . .\ . /
. . . . .X
. . . ./ . \
. . ./. . . .\
. ./. . . . . .\
LR . . . . . . RR LF+RR=50%
This is very over-simplified, and there are subtleties to account for in each unique suspension design. But it should give you an idea of how to get started. Once you are satisfied with the final ride heights and weight percentages, you should obviously finish off with a good alignment.
Hope that helps.
.
It involves using a set of car scales that have four scale pads - one to be placed under each wheel, that are joined to a common console that shows the weight supported by each independent wheel. It can show (diagonal) cross-weight, or the sum of any combination or ALL of the individual weights. This is the same type of scales used in impound at SCCA Nationals, National Tours, ProSolos, etc.. But the better performance alignment shops have them and/or you can buy a set from RacerWholesale and other race shops. This process needs to be done on a perfectly level and even surface to ensure accuracy.
In its simplest form, your intent is to use these scales to balance the car's weight Diagonally (LF to RR, RF to LR), Front to Back and Left to Right as accurately as is practical. You do this by adjusting the ride height of each shock individually while watching the weights move around. As you lower one corner, you are essentially 'Tilting' the car towards that corner, thereby INCREASING the percentage of static load (weight) that corner carries.
You start by setting each coilover's ride height so the car is even and level, with the basic amount of drop from stock that you want. Measure the arch height-to-ground on each wheel well, adjust each shock until the car is level, then establish the rake that you want (if any). Make sure the suspension does not have a chance to bottom-out due to lack of travel, because if you set it too low, it will hit or ride on the bump-stops and induce what is called bump steer, a dangerous condition that could cause you to lose control. Run-in the new springs with this basic configuration locked down for a bit before messing with the scales to make sure they are fully seated and settled-in.
Then, when you put the car on the scales, make sure the suspension is loaded like normal (and can move freely - not in any bind) and plan for a few hours of tweaking...
Obviously, given the front-heavy weight bias of the MINI, there is just so much you can do to level the weight F-to-R by changing the ride height of coilovers. But, you can still send a little weight to the back without making the front all jacked-up and the rear scrape the ground (in other words, use some common sense with your settings).
To do cross-weight comparisons, set the scale controller to display one front and one rear (the rear opposite side as the front, as shown below) and adjust each corner's ride height so that the LF+RR pair supports the EXACT same percentage of weight as the RF+LR pair WITH the driver sitting in the driver seat just as the car would be driven. 50% is ideal, of course.
LF . . . . . . RF RF+LR=50%
. .\ . . . . . /
. . .\ . . . /
. . . .\ . /
. . . . .X
. . . ./ . \
. . ./. . . .\
. ./. . . . . .\
LR . . . . . . RR LF+RR=50%
This is very over-simplified, and there are subtleties to account for in each unique suspension design. But it should give you an idea of how to get started. Once you are satisfied with the final ride heights and weight percentages, you should obviously finish off with a good alignment.
Hope that helps.
.
Wow I am overwhelmed to say the least
Well thanks for all the detail. I am going to have to know this stuff inside out if I am going to run my car with all the bells and whistles. Thanks for that detailed info...now my head hurts
:impatient
Well thanks for all the detail. I am going to have to know this stuff inside out if I am going to run my car with all the bells and whistles. Thanks for that detailed info...now my head hurts :impatient
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3rd Gear
Joined: Jan 2005
Posts: 175
Likes: 0
From: Near Charlotte, NC
One more thing - if YOU want to be the one doing the actual adjustments or observing the process instead of just sitting in the driver's seat, then either find someone else that's about your weight to sit there in your place (tell them to be STILL 
), or you can simulate your weight with sandbags or weights 'borrowed' from your favorite gym 
.
.
), or you can simulate your weight with sandbags or weights 'borrowed' from your favorite gym ..
3rd Gear
Joined: Jan 2005
Posts: 175
Likes: 0
From: Near Charlotte, NC
And another thing...
If you intend to auto-x or track your car, then set the car up as CLOSE as possible to the condition it will be raced in.
Get rid of any stuff in the cockpit or boot that wouldn't be there when it's on track. If you typically autocross with very little gas, then show up at the scales with the tank nearly empty (remember that gas weighs 7 pounds per gallon... and this exercise is all about WEIGHT!!).
If you swap your heavy street wheels with really light wheels for events, then put the light rims on before boarding the scales. Though most percentages of weights would not change since all four wheels weigh the same, this is a golden opportunity to find out EXACTLY what your car weighs in race trim.
.
If you intend to auto-x or track your car, then set the car up as CLOSE as possible to the condition it will be raced in.
Get rid of any stuff in the cockpit or boot that wouldn't be there when it's on track. If you typically autocross with very little gas, then show up at the scales with the tank nearly empty (remember that gas weighs 7 pounds per gallon... and this exercise is all about WEIGHT!!).
If you swap your heavy street wheels with really light wheels for events, then put the light rims on before boarding the scales. Though most percentages of weights would not change since all four wheels weigh the same, this is a golden opportunity to find out EXACTLY what your car weighs in race trim.
.
The alignment shop I use described it this way...
If you think of your car as a four legged table, the corner balancing is akin to changing the length of the legs so it doesn't rock.
Not a perfect analogy, but close.
Also, you won't change the wight distribution much, the Mini will always be front biased.
But you will get the best traction you can out of the adjusatable shocks.
Matt
Not a perfect analogy, but close.
Also, you won't change the wight distribution much, the Mini will always be front biased.
But you will get the best traction you can out of the adjusatable shocks.
Matt
6th Gear
Joined: Sep 2004
Posts: 5,149
Likes: 0
Originally Posted by Coopernicus
I'm not "Dr. Meb" or Onasled, and haven't done this in a few years, so please don't flame me if I get a detail wrong here or there - I am only trying to help.
It involves using a set of car scales that have four scale pads - one to be placed under each wheel, that are joined to a common console that shows the weight supported by each independent wheel. It can show (diagonal) cross-weight, or the sum of any combination or ALL of the individual weights. This is the same type of scales used in impound at SCCA Nationals, National Tours, ProSolos, etc.. But the better performance alignment shops have them and/or you can buy a set from RacerWholesale and other race shops. This process needs to be done on a perfectly level and even surface to ensure accuracy.
In its simplest form, your intent is to use these scales to balance the car's weight Diagonally (LF to RR, RF to LR), Front to Back and Left to Right as accurately as is practical. You do this by adjusting the ride height of each shock individually while watching the weights move around. As you lower one corner, you are essentially 'Tilting' the car towards that corner, thereby INCREASING the percentage of static load (weight) that corner carries.
You start by setting each coilover's ride height so the car is even and level, with the basic amount of drop from stock that you want. Measure the arch height-to-ground on each wheel well, adjust each shock until the car is level, then establish the rake that you want (if any). Make sure the suspension does not have a chance to bottom-out due to lack of travel, because if you set it too low, it will hit or ride on the bump-stops and induce what is called bump steer, a dangerous condition that could cause you to lose control. Run-in the new springs with this basic configuration locked down for a bit before messing with the scales to make sure they are fully seated and settled-in.
Then, when you put the car on the scales, make sure the suspension is loaded like normal (and can move freely - not in any bind) and plan for a few hours of tweaking...
Obviously, given the front-heavy weight bias of the MINI, there is just so much you can do to level the weight F-to-R by changing the ride height of coilovers. But, you can still send a little weight to the back without making the front all jacked-up and the rear scrape the ground (in other words, use some common sense with your settings).
To do cross-weight comparisons, set the scale controller to display one front and one rear (the rear opposite side as the front, as shown below) and adjust each corner's ride height so that the LF+RR pair supports the EXACT same percentage of weight as the RF+LR pair WITH the driver sitting in the driver seat just as the car would be driven. 50% is ideal, of course.
LF . . . . . . RF RF+LR=50%
. .\ . . . . . /
. . .\ . . . /
. . . .\ . /
. . . . .X
. . . ./ . \
. . ./. . . .\
. ./. . . . . .\
LR . . . . . . RR LF+RR=50%
This is very over-simplified, and there are subtleties to account for in each unique suspension design. But it should give you an idea of how to get started. Once you are satisfied with the final ride heights and weight percentages, you should obviously finish off with a good alignment.
Hope that helps.
.
It involves using a set of car scales that have four scale pads - one to be placed under each wheel, that are joined to a common console that shows the weight supported by each independent wheel. It can show (diagonal) cross-weight, or the sum of any combination or ALL of the individual weights. This is the same type of scales used in impound at SCCA Nationals, National Tours, ProSolos, etc.. But the better performance alignment shops have them and/or you can buy a set from RacerWholesale and other race shops. This process needs to be done on a perfectly level and even surface to ensure accuracy.
In its simplest form, your intent is to use these scales to balance the car's weight Diagonally (LF to RR, RF to LR), Front to Back and Left to Right as accurately as is practical. You do this by adjusting the ride height of each shock individually while watching the weights move around. As you lower one corner, you are essentially 'Tilting' the car towards that corner, thereby INCREASING the percentage of static load (weight) that corner carries.
You start by setting each coilover's ride height so the car is even and level, with the basic amount of drop from stock that you want. Measure the arch height-to-ground on each wheel well, adjust each shock until the car is level, then establish the rake that you want (if any). Make sure the suspension does not have a chance to bottom-out due to lack of travel, because if you set it too low, it will hit or ride on the bump-stops and induce what is called bump steer, a dangerous condition that could cause you to lose control. Run-in the new springs with this basic configuration locked down for a bit before messing with the scales to make sure they are fully seated and settled-in.
Then, when you put the car on the scales, make sure the suspension is loaded like normal (and can move freely - not in any bind) and plan for a few hours of tweaking...
Obviously, given the front-heavy weight bias of the MINI, there is just so much you can do to level the weight F-to-R by changing the ride height of coilovers. But, you can still send a little weight to the back without making the front all jacked-up and the rear scrape the ground (in other words, use some common sense with your settings).
To do cross-weight comparisons, set the scale controller to display one front and one rear (the rear opposite side as the front, as shown below) and adjust each corner's ride height so that the LF+RR pair supports the EXACT same percentage of weight as the RF+LR pair WITH the driver sitting in the driver seat just as the car would be driven. 50% is ideal, of course.
LF . . . . . . RF RF+LR=50%
. .\ . . . . . /
. . .\ . . . /
. . . .\ . /
. . . . .X
. . . ./ . \
. . ./. . . .\
. ./. . . . . .\
LR . . . . . . RR LF+RR=50%
This is very over-simplified, and there are subtleties to account for in each unique suspension design. But it should give you an idea of how to get started. Once you are satisfied with the final ride heights and weight percentages, you should obviously finish off with a good alignment.
Hope that helps.
.
6th Gear
Joined: Jan 2003
Posts: 3,301
Likes: 1
I think this is a great explanation! Just don't forget that you or an equal weight depicting you must be in the car during this operation.
Final thought; becasue your weight is part of the calculation, the weight left to right over a given axle will more than likely not be the same. It is important to get to 50% cross weight. Your car will be very predicitable in terms of weight transfer if you can do this. Getting left to right weights the same requires moving stuff around. If you can accomplish this it is a good thing...probably not possible...
Final thought; becasue your weight is part of the calculation, the weight left to right over a given axle will more than likely not be the same. It is important to get to 50% cross weight. Your car will be very predicitable in terms of weight transfer if you can do this. Getting left to right weights the same requires moving stuff around. If you can accomplish this it is a good thing...probably not possible...
Originally Posted by Coopernicus
I'm not "Dr. Meb" or Onasled, and haven't done this in a few years, so please don't flame me if I get a detail wrong here or there - I am only trying to help.
It involves using a set of car scales that have four scale pads - one to be placed under each wheel, that are joined to a common console that shows the weight supported by each independent wheel. It can show (diagonal) cross-weight, or the sum of any combination or ALL of the individual weights. This is the same type of scales used in impound at SCCA Nationals, National Tours, ProSolos, etc.. But the better performance alignment shops have them and/or you can buy a set from RacerWholesale and other race shops. This process needs to be done on a perfectly level and even surface to ensure accuracy.
In its simplest form, your intent is to use these scales to balance the car's weight Diagonally (LF to RR, RF to LR), Front to Back and Left to Right as accurately as is practical. You do this by adjusting the ride height of each shock individually while watching the weights move around. As you lower one corner, you are essentially 'Tilting' the car towards that corner, thereby INCREASING the percentage of static load (weight) that corner carries.
You start by setting each coilover's ride height so the car is even and level, with the basic amount of drop from stock that you want. Measure the arch height-to-ground on each wheel well, adjust each shock until the car is level, then establish the rake that you want (if any). Make sure the suspension does not have a chance to bottom-out due to lack of travel, because if you set it too low, it will hit or ride on the bump-stops and induce what is called bump steer, a dangerous condition that could cause you to lose control. Run-in the new springs with this basic configuration locked down for a bit before messing with the scales to make sure they are fully seated and settled-in.
Then, when you put the car on the scales, make sure the suspension is loaded like normal (and can move freely - not in any bind) and plan for a few hours of tweaking...
Obviously, given the front-heavy weight bias of the MINI, there is just so much you can do to level the weight F-to-R by changing the ride height of coilovers. But, you can still send a little weight to the back without making the front all jacked-up and the rear scrape the ground (in other words, use some common sense with your settings).
To do cross-weight comparisons, set the scale controller to display one front and one rear (the rear opposite side as the front, as shown below) and adjust each corner's ride height so that the LF+RR pair supports the EXACT same percentage of weight as the RF+LR pair WITH the driver sitting in the driver seat just as the car would be driven. 50% is ideal, of course.
LF . . . . . . RF RF+LR=50%
. .\ . . . . . /
. . .\ . . . /
. . . .\ . /
. . . . .X
. . . ./ . \
. . ./. . . .\
. ./. . . . . .\
LR . . . . . . RR LF+RR=50%
This is very over-simplified, and there are subtleties to account for in each unique suspension design. But it should give you an idea of how to get started. Once you are satisfied with the final ride heights and weight percentages, you should obviously finish off with a good alignment.
Hope that helps.
.
It involves using a set of car scales that have four scale pads - one to be placed under each wheel, that are joined to a common console that shows the weight supported by each independent wheel. It can show (diagonal) cross-weight, or the sum of any combination or ALL of the individual weights. This is the same type of scales used in impound at SCCA Nationals, National Tours, ProSolos, etc.. But the better performance alignment shops have them and/or you can buy a set from RacerWholesale and other race shops. This process needs to be done on a perfectly level and even surface to ensure accuracy.
In its simplest form, your intent is to use these scales to balance the car's weight Diagonally (LF to RR, RF to LR), Front to Back and Left to Right as accurately as is practical. You do this by adjusting the ride height of each shock individually while watching the weights move around. As you lower one corner, you are essentially 'Tilting' the car towards that corner, thereby INCREASING the percentage of static load (weight) that corner carries.
You start by setting each coilover's ride height so the car is even and level, with the basic amount of drop from stock that you want. Measure the arch height-to-ground on each wheel well, adjust each shock until the car is level, then establish the rake that you want (if any). Make sure the suspension does not have a chance to bottom-out due to lack of travel, because if you set it too low, it will hit or ride on the bump-stops and induce what is called bump steer, a dangerous condition that could cause you to lose control. Run-in the new springs with this basic configuration locked down for a bit before messing with the scales to make sure they are fully seated and settled-in.
Then, when you put the car on the scales, make sure the suspension is loaded like normal (and can move freely - not in any bind) and plan for a few hours of tweaking...
Obviously, given the front-heavy weight bias of the MINI, there is just so much you can do to level the weight F-to-R by changing the ride height of coilovers. But, you can still send a little weight to the back without making the front all jacked-up and the rear scrape the ground (in other words, use some common sense with your settings).
To do cross-weight comparisons, set the scale controller to display one front and one rear (the rear opposite side as the front, as shown below) and adjust each corner's ride height so that the LF+RR pair supports the EXACT same percentage of weight as the RF+LR pair WITH the driver sitting in the driver seat just as the car would be driven. 50% is ideal, of course.
LF . . . . . . RF RF+LR=50%
. .\ . . . . . /
. . .\ . . . /
. . . .\ . /
. . . . .X
. . . ./ . \
. . ./. . . .\
. ./. . . . . .\
LR . . . . . . RR LF+RR=50%
This is very over-simplified, and there are subtleties to account for in each unique suspension design. But it should give you an idea of how to get started. Once you are satisfied with the final ride heights and weight percentages, you should obviously finish off with a good alignment.
Hope that helps.
.
3rd Gear
Joined: Jan 2005
Posts: 175
Likes: 0
From: Near Charlotte, NC
Originally Posted by RED FURY
Most "regular shops" can't do it, you need a race shop, that preps cars for the track
Originally Posted by CDMINI
So how much (approximately) should a corner balancing for a MINI cost at a shop? - for example a car with Bilstein PSS9's.
.
Temporarily Banned
Joined: Oct 2002
Posts: 3,382
Likes: 2
From: Denver
The MINI can be 50% cross weighted - our car is.
Great info!
For example's sake, we charge based on the time it takes. Some cars are very close and it doesn't take much fiddling. Others are way off and we charge accordingly. I'd say anywhere from $85 to $200.
Hope that helps!
Randy
Great info!
For example's sake, we charge based on the time it takes. Some cars are very close and it doesn't take much fiddling. Others are way off and we charge accordingly. I'd say anywhere from $85 to $200.
Hope that helps!
Randy
6th Gear
Joined: Jan 2003
Posts: 3,301
Likes: 1
you can try Meccanics Shop north in Salem, NY. Ask for Anthony. The are times when he is friendly, times when he is not and times when he is aloof.
If you can get into Fairfield county Connecticut I can help with more suggestions - Westport, Stanford.
Hey Onasled! your picture printed an image before the computer downloaded the whole thing...wus up with that . I see you're taking the racing bug thing very seriously
If you can get into Fairfield county Connecticut I can help with more suggestions - Westport, Stanford.
Hey Onasled! your picture printed an image before the computer downloaded the whole thing...wus up with that
. I see you're taking the racing bug thing very seriously
Originally Posted by K9MINI
Thanks Guys!
Anyone know of a race prep shop in the NY/NJ around Bergen or Rockland County?
Anyone know of a race prep shop in the NY/NJ around Bergen or Rockland County?
3rd Gear
Joined: Jan 2005
Posts: 175
Likes: 0
From: Near Charlotte, NC
- Onasled -
That is a very easy-to-read view of a fine "balancing act".
BTW - Are those Bilstein PSS9's peaking out from your signature pic? If so, do you think they are a good compromise of ride & handling for a dual-use street/track car? I want coilovers, but don't want a buck board for my daily driver....
THANKS.
.
That is a very easy-to-read view of a fine "balancing act"
.BTW - Are those Bilstein PSS9's peaking out from your signature pic? If so, do you think they are a good compromise of ride & handling for a dual-use street/track car? I want coilovers, but don't want a buck board for my daily driver....
THANKS.
.
Originally Posted by Coopernicus
- Onasled -.......Are those Bilstein PSS9's peaking out from your signature pic? If so, do you think they are a good compromise of ride & handling for a dual-use street/track car? I want coilovers, but don't want a buck board for my daily driver....
THANKS.
.
THANKS.
.
They are coming off though, to be replaced with Motons. And sorry, they are spoken for ...
Another quote point...
I'm going in for ride height, corner balance and alignment at Custom Alignment in Mt View. Front and real alignment is $240 (for those that want to know what they charge for an excellent alignement), and ride height and corner balance brings the total to $615. They aren't the cheapest around, but you don't leave until it's right.
Matt
Matt
3rd Gear
Joined: Jan 2005
Posts: 175
Likes: 0
From: Near Charlotte, NC
Onasled -
Thanks for the recommendation. I think that is the direction I will take for suspension upgrades, along with some Helix/RDR camber plates.
Enjoy your Moton experience!! I've "Been there, Done that" with Motons on my Porsche Boxster S back in 2001. Lex Carson and Jerome Van Gool of Moton are GOOD PEOPLE!!
Do they have any Club Sport models for the MINI yet? I simply can't justify $6k for MINI shocks like I did for the Porsche...
.
Thanks for the recommendation. I think that is the direction I will take for suspension upgrades, along with some Helix/RDR camber plates.
Enjoy your Moton experience!! I've "Been there, Done that" with Motons on my Porsche Boxster S back in 2001. Lex Carson and Jerome Van Gool of Moton are GOOD PEOPLE!!
Do they have any Club Sport models for the MINI yet? I simply can't justify $6k for MINI shocks like I did for the Porsche...
.