Weight distribution and suspension setup

[br77]

Hello guys,

Just want to get some ideas on how to set the correct height of the car using coilover / lowered spring.

Let's using an example (unusual case) here, if adults weigh 200kg sit at the back, adults weigh 140kg sit at the front, and also have 80kg loaded in the boot. What sort of clearance should be looking at assuming spring rate is 10?

I am thinking of 370mm center to guard distance on each wheel (20s) but unsure if the weight is going to be equally distribution to each spring.

Many thanks if somebody can educate me with suggestions.

 

[lowandslow]

It's a 1700kg family sedan. Not a V8 Supercar.

Set it to a practical height that looks mint and enjoy it.

 

[manuelmanuel]

Hey mate, if you have coilovers and you want to properly set them up, you need to take it to suspension specialist who can corner weight the car,
as in each wheel corner is put on scales and then the height is adjusted from their to get the best possible weight distribution.
This might be overkill to some, but it is only way to properly setup coilovers.

 

[br77]

It's a 1700kg family sedan. Not a V8 Supercar.

Set it to a practical height that looks mint and enjoy it.

Thanks mate, just want to do a math before installing the kit.

 

[br77]

Yes mate, just want to ask if two adults sitting at the back. Eg 90kg per person, will each rear spring be forced by 90kg. Which will lower the car further by 9mm on a spring with 10kg rate?

 

[manuelmanuel]

Not sure on that.

 

[panhead]

Hey mate, if you have coilovers and you want to properly set them up, you need to take it to suspension specialist who can corner weight the car,
as in each wheel corner is put on scales and then the height is adjusted from their to get the best possible weight distribution.
This might be overkill to some, but it is only way to properly setup coilovers.

This is how two of my cars are setup plus with allowances for the driver only.

 

[panhead]

Yes mate, just want to ask if two adults sitting at the back. Eg 90kg per person, will each rear spring be forced by 90kg. Which will lower the car further by 9mm on a spring with 10kg rate?

Actually that sounds about right for the difference mine has for the driver only.

Even if the setup is done in a shop they need to test run after the first dial in and possibly make adjustments so if you’re doing it at home why not throw a couple of people in the back after you’ve installed them and do a few calcs to help get it right.

 

[vc commodore]

Hey mate, if you have coilovers and you want to properly set them up, you need to take it to suspension specialist who can corner weight the car,
as in each wheel corner is put on scales and then the height is adjusted from their to get the best possible weight distribution.
This might be overkill to some, but it is only way to properly setup coilovers.

Corner weighting done like this is only done if you're racing the car professionally. So unless you're planning on using the car to race and earn a living racing it, this is massive over kill....

BTW, I set up weekend race cars for the novice race drivers and none of these cars are done by corner weighting, because it's pure wank for a street driven car.

All that is required to set coil overs up is a tape measure.....With the car level, measure from the base of the rim to the base of the guard and adjust every corner of the car accordingly to the height you want.

The right hand front will need to be set a smidge lower, to counter act the weight of the driver.....To set this, just take a measurement, with the car sitting driverless.....Then with the help of a mate, the regular driver sits in the drivers seat and the mate then takes a measurement...From that, deduct the difference and lower accordingly, so it sits perfectly level when driving the car.

FWIW, if you're going the pure wank factor of corner weighting, especially with scales, you'd be adjusting them constantly, as you'd have people constantly in and out of the car, along with baggage/shopping etc etc, therefore the height will constantly be changing....constantly changing height = constant adjusting of the shocks to get the wank factor perfect all the time

 

[br77]

Corner weighting done like this is only done if you're racing the car professionally. So unless you're planning on using the car to race and earn a living racing it, this is massive over kill....

BTW, I set up weekend race cars for the novice race drivers and none of these cars are done by corner weighting, because it's pure wank for a street driven car.

All that is required to set coil overs up is a tape measure.....With the car level, measure from the base of the rim to the base of the guard and adjust every corner of the car accordingly to the height you want.

The right hand front will need to be set a smidge lower, to counter act the weight of the driver.....To set this, just take a measurement, with the car sitting driverless.....Then with the help of a mate, the regular driver sits in the drivers seat and the mate then takes a measurement...From that, deduct the difference and lower accordingly, so it sits perfectly level when driving the car.

FWIW, if you're going the pure wank factor of corner weighting, especially with scales, you'd be adjusting them constantly, as you'd have people constantly in and out of the car, along with baggage/shopping etc etc, therefore the height will constantly be changing....constantly changing height = constant adjusting of the shocks to get the wank factor perfect all the time

Thanks all for the suggestions, I wouldn't be doing the comer weighting, but just want to do a math to avoid scraping arch and lower it to a decent level. Not using this car for racing haha