8 replies to this topic

[weeally]

Morning,

I do apologise for this thread as I know there are many out there on this topic
Due to keeping cost down just now to get the car on the road I'm using mostly what came with the car.
So I have complete adjustability front and rear, starmag 7x13 and has been lowered. I have a gunson camber gauge I have set the tie rods to the same size as standard 362mm.
I'm getting confused with setting it up briefly to get it down for a mot.
After looking at youtube videos and reading the threads here there seems to be different ways of doing this.

1. Zero gauge at straight ahead, 20 degrees out take reading, 20 degrees in take reading and add then together and X 1.5

2. 20 degrees out zero gauge, 20 degrees in take reading

3. 20 degrees in zero gauge, 20 degrees out take reading

The readings I'm getting are wild and all different when using any of those mentioned.

Thanks in advance

[Spider]

The formula I have been using for a long time ;-
 

Caster (deg) = (180 / 3.1415) x [(camber1 - camber2) / (turnangle1 - turnangle2)]

So, I measure a Camber Angle (Camber 1) with the wheel turned in at 20 degrees (Turnangle 1) and note them down. Then Turn out 20 degrees (Turnangle 2) and measure the Camber Angle (Camber 2) there, then punch those numbers in to the above formula.
 

[weeally]

Sorry spider that has blown my mind. I'm such a simple creature.

[nicklouse]

Morning,

I do apologise for this thread as I know there are many out there on this topic
Due to keeping cost down just now to get the car on the road I'm using mostly what came with the car.
So I have complete adjustability front and rear, starmag 7x13 and has been lowered. I have a gunson camber gauge I have set the tie rods to the same size as standard 362mm.
I'm getting confused with setting it up briefly to get it down for a mot.
After looking at youtube videos and reading the threads here there seems to be different ways of doing this.

1. Zero gauge at straight ahead, 20 degrees out take reading, 20 degrees in take reading and add then together and X 1.5

2. 20 degrees out zero gauge, 20 degrees in take reading

3. 20 degrees in zero gauge, 20 degrees out take reading

The readings I'm getting are wild and all different when using any of those mentioned.

Thanks in advance

Are you using some turntables or a slippy floor?

[fatcatvera]

I've taken approach 2 & 3 on your list - i.e. measured the camber change for a 40degree swing centred on straight ahead.

 

I was looking a for an error causing a pull to the left. the figures I measured were 3.5degrees caster on the LHF and 5.5degrees caster on the RHF. I corrected this RHF to 3.5degrees by modifying the drag link (by cutting the brakets off the end and rewelding them back 6mm ish longer). this gave me 0.5dgree negative camber on the LHF and 1.5degrees negative camber on the RHF which isn't ideal but corrected my pulling issue and is ultimately only slightly out of tolerance. I'd rather have the camber error than the castor error. If I had adjustable bottom arms I'd have balanced up the cambers too, obvs.

[weeally]

Morning,

I do apologise for this thread as I know there are many out there on this topic
Due to keeping cost down just now to get the car on the road I'm using mostly what came with the car.
So I have complete adjustability front and rear, starmag 7x13 and has been lowered. I have a gunson camber gauge I have set the tie rods to the same size as standard 362mm.
I'm getting confused with setting it up briefly to get it down for a mot.
After looking at youtube videos and reading the threads here there seems to be different ways of doing this.

1. Zero gauge at straight ahead, 20 degrees out take reading, 20 degrees in take reading and add then together and X 1.5

2. 20 degrees out zero gauge, 20 degrees in take reading

3. 20 degrees in zero gauge, 20 degrees out take reading

The readings I'm getting are wild and all different when using any of those mentioned.

Thanks in advance

Are you using some turntables or a slippy floor?

Slippy floor method under the tyres with masking tape set parallel and then 20 degrees out and degrees in.

I was just looking to confirm what I was doing was correct.
I know this is not the greatest but its so I can get it down to the garage get tracking and geometry done along with its Mot.

Edited by weeally, 18 March 2022 - 12:53 PM.

[Spider]

Sorry spider that has blown my mind. I'm such a simple creature.

 

Me too !

With most equipment, there's no direct way of measuring it, so it's a calculation based off turning angles and camber angles at the turned angles.

 

Another way to 'set' it, though you won't know what the angles are, if you have some good flat roadway preferably quiet, you can set it by trial and error. Set one side (driver's would be best), then go for a short drive (make sure the tyre pressures are the same). If it pulls to the diver's side, the passenger's caster rod is too long, shorten it by 1/2 a turn and try again. Keep going with this until it steers neutral. Then keep going doing this until it pulls the other way. Finally, set it 1/2 way between where you first started felling it drive neutral until the setting before it started pulling the other way. You'll want to check and likely set the Camber Angle on the passenger's side again as that will change with the Change in Caster Angle and then go over the driving checks again for the Caster Angle. Finally, set the Toe Angle last. Keep in mind as well that the attitude (height difference between front and rear) also changes the Caster Angle.

Coming back to the actual angles, just my own view here, but the actual numbers you come up with don't matter one bit. Drive the car and see what it's telling you, then adjust from there. Getting the car to feel and respond to your expectations at the end of the day is what it's all about.

One last thing that seems to loose many people but bear with me here. Again, just my own 'taste' but based on experience. I like to set my wheels to Zero Camber Angle. This gives the best compromise between Accelerating and Braking Traction, though, if the suspension is set particularly low, then about 1/2 to maybe 1 degree Negative maybe advantageous here.

Dial in as much Caster Angle as you can put up with (the more Caster, the Heavier the steering gets as speed builds up). When the front wheels are set with these angles, while there's zero camber angle with the wheels in a straight ahead position, when you start turning, the outside wheel will progressively go in to a Negative Camber Angle and Inside Wheel, Positive. With the natural sidewall flex in the tyres, this improves the grip of the tyres to the road.

There is another down side to having high Caster Angles and that is it does make the feelback to the driver more sensitive variable road surfaces, if (when) the surface is difference between each side ie, it will make the car more 'twitchy', some mistakenly often call it 'torque steer', but that it's definitely not.

[coopertaz]

when setting all these put 2 square metal plates under wheel with sand and grease on helps to prevent drag on floor

[weeally]

Thanks for the responses. Got it set, we will see how far off I am when it goes and gets it all done at the garage before it's MOT