AstinaGT Forums - View Single Post - HOW TO: Adjust your BJ caster and camber at the front wheels

Old Grey · 04-04-2009, 09:32 PM

Just posting a trick to cheaply check your camber

1 Drive on to a flat surface, eg driveway, with the wheels pointing straight. Don't reverse or jack up the car

2 Place a spirit level vertically next to the wheel so it passes through the center of the wheel, basically parallel to the wheel. Rest the top of the level against the guard and move the bottom of the level in or out until the bubble is in the center of the lines.

3 Measure the distance between the top of the wheel rim to the level and then the bottom of the rim to the level. This is based on your rim not being bent.

4 The difference between the dimensions can be used to calculate the camber angle

Sin x-1 = difference top to bottom/rim diameter edge to edge

difference top to bottom = 7mm, eg top 30mm bottom 23mm, 30-23 =7mm
rim diameter edge to edge = 390mm measured directly off my 14" rim
Sin x-1 = 7/390 = 1.028º

If the bottom dimension is smaller than the top you have negative camber

When you get good you should be able to get good repeatably
Remember if you change the strut top you will have to resettle the car by driving around the block

My RX7 on the rear has 15mm top to bottom on a 15" rim and wears on the inside, the front has 8mm

My BG Astina has 6mm on the left and 0mm on the right

To check if your spirit level is accurate place it against a door jam on your house and see how close it is, then spin the level around so that you are using the other side and the same bubble. Both sides should read the same

Remember the guard is different distances to the wheel on both sides of the car so don't be supprised if they are different, you just want the difference between the top and bottom

If you want a neat picture of where the wear will be try this
http://www.michelintransport.com/ple...ERTURE&lang=EN

04-04-2009, 09:32 PM	#78
Old Grey Junior Member Join Date: Apr 2009 Location: Sydney Car: Astina BG 1991 - Rx7 S4 Posts: 105	Just posting a trick to cheaply check your camber 1 Drive on to a flat surface, eg driveway, with the wheels pointing straight. Don't reverse or jack up the car 2 Place a spirit level vertically next to the wheel so it passes through the center of the wheel, basically parallel to the wheel. Rest the top of the level against the guard and move the bottom of the level in or out until the bubble is in the center of the lines. 3 Measure the distance between the top of the wheel rim to the level and then the bottom of the rim to the level. This is based on your rim not being bent. 4 The difference between the dimensions can be used to calculate the camber angle Sin x-1 = difference top to bottom/rim diameter edge to edge difference top to bottom = 7mm, eg top 30mm bottom 23mm, 30-23 =7mm rim diameter edge to edge = 390mm measured directly off my 14" rim Sin x-1 = 7/390 = 1.028º If the bottom dimension is smaller than the top you have negative camber When you get good you should be able to get good repeatably Remember if you change the strut top you will have to resettle the car by driving around the block My RX7 on the rear has 15mm top to bottom on a 15" rim and wears on the inside, the front has 8mm My BG Astina has 6mm on the left and 0mm on the right To check if your spirit level is accurate place it against a door jam on your house and see how close it is, then spin the level around so that you are using the other side and the same bubble. Both sides should read the same Remember the guard is different distances to the wheel on both sides of the car so don't be supprised if they are different, you just want the difference between the top and bottom If you want a neat picture of where the wear will be try this http://www.michelintransport.com/ple...ERTURE&lang=EN Last edited by Old Grey; 04-04-2009 at 09:53 PM.