DIY adjustable camber ball joints mod

[Notso Swift]

Depending on the tyres 2 deg is low for track only but pretty much the limit if you are driving on street (ie to and from events). Hillclimbs being so traction dependent and relatively low speed I think you are in a good position
Most strut tops are stet up for either Camber or Castor, You want as much castor as possible on FWD so it is common enough to do bulk movements of camber from the bottom (balljoint or strut leg) and fine tune from the top hat keeping the castor

[sambb]

I'm on 5/1/2 degrees of castor at the moment. Down the track ill reposition my offset rear LCA bolts that are currently in the "anti-dive" position to the castor position. If doing this mod loses me some castor I can get it back that way. Looking at where the joint sits I think there might be a lot more castor in it too. Where does my 5/1/2 degrees fit against other polos??

Yeah it'd be so much easier if we didn't have the stupid strut in hub socket arrangement. My mates clio w172 has the hubs bolt onto a two bolt strut flange. You just put in an eccentric on the top hole and instantly tilt the hub top in against the strut. You get camber without adjusting the SAI at all. We are forced to move SAI when we do camber (top or bottom) which isn't ideal from a geometry standpoint and cost $$ too.
Notso swift - what do you reckon regarding the forces at play down at the ball joint. The joint is going to sit further out (0.75 dgerees or so extra) which gives the joint more leverage over the outer two bolt positions (which remain unmolested) - but the centre bolt fits deeper into the arm. I'm using high tensiles and the surface area of the audi joints mounting surfaces is bigger than OE so offers up a better compression/sandwhich fit inside the arm. Its going to be strong as hell to my eyes - what do you think?

[Martin]

-1.75 degrees of camber is not enough to make a noticeable difference to cornering performance.

Depends

I ran -1.75 degrees on my Skoda Octavia for a few years of daily street driving
This made a huge difference to turn in performance and it did result in some featuring of the inside edge
I could also brake deep into a corner, turning and braking at the same time, it was incredible
(I have supaloy control arms - much like the Audi TT)

But from a motorsport point of view -1.75 is nothing

It's not enough to balance tyre wear either, you'll still wear the outside of the tyre a lot.

During motorsport (or maybe extremely hard street usage) - yes

For most people, daily motoring, -1.75 deg is way too much negative
My wife's Mazda 3 SP23 had -2 deg negative at the rear,
she wore out the inside edge of the tyres due to excessive negative camber
I've now reduced the rear to -1 deg

I'm running -3.5 on my left, -2.5 on the right (as I run right handed circuits), and it's my shoulders that show more signs of wear.

Extremely hard driving and motorsport usage will do this to a Macpherson struct FWD
Stiffer springs (maybe stiffer sway bar), tyres with a stiffer side wall and higher tyre pressures will all help
But ultimately, under sever conditions, there is no substitute for negative camber
I'm running -5 deg on the front of a Nissan Pulsar (2L NA FWD) for track only usage

[Martin]

No I have standard tops. I looked into tops and the money was outlandish when I could basically achieve the exact same thing at the base instead. I could do the work myself and it hasn't cost me more than 180 bucks. Provided the stubs fit the hub it will work. Stuff like this is sold for just about every VW hatch except ours and the fabia mk2 guys have been doing this mod all over the world. It could be an issue but I doubt there'll be any drive shaft problems - so I just figured I'd make some. Like I said earlier I'm not after big camber numbers, just whats going to be effective on the hillclimbs - it still has to get the power down when the car gets straightened up. Plus its camber that increases front track, if it works its gotta be betterer.

On the drive shafts, all cars are different but many will tolerate ~10mm wider (each side!)
The bigger problem for FWD is don't go low - for two reasons:
-Likely to regularly destroy CV joints
-Moves the center of mass further away from the roll center creating more problems than benefits

What you're doing is increasing static camber - this does help cornering but as you go further it will make the car crown sensitive and give rise to other undesirable handling traits - but it's the cheap and easy way to get some improvement

Dynamic camber is a far better goal - when you have a lot of castor, turning the steering wheel gives you negative camber - this works much better all round (cornering, straight line, braking, etc)
Hence, slotting the top of the strut tower to get as much castor as possible would be the best option - if the car is a track car (rather than a daily)

See the the different setup on my track cars:
Nissan Pulsar has very low castor so I'm running -5 deg camber
Nissan 350z has 8 degrees of castor, because of that I only need -2 deg camber

[sambb]

From what I can gather , by running higher profile sidewalls eg 205/50/15 my forward traction would be less sensitive to excessive camber as opposed to say 40/17's with the same camber. Do you reckon I could get away with more than 2 degrees doing hillclimbs considering the profile of A050's that I run, without hurting power down.

[Martin]

I'm on 5/1/2 degrees of castor at the moment. Where does my 5/1/2 degrees fit against other polos??

Dunno about Polo specs but it's much more than my Pulsar and a far bit less than my 350Z
I would thing you're in a pretty good spot (from a castor point of view) for a FWD

Yeah it'd be so much easier if we didn't have the stupid strut in hub socket arrangement. My mates clio w172 has the hubs bolt onto a two bolt strut flange. You just put in an eccentric on the top hole and instantly tilt the hub top in against the strut. You get camber without adjusting the SAI at all. We are forced to move SAI when we do camber (top or bottom) which isn't ideal from a geometry standpoint and cost $$ too.

SAI effect is low - you may loose a little steering feel but you're unlikely to notice it due to PWR steering

Eccentrics for strut camber adjustment are not wonderful
It's a technique originally created to fix the alignment of crashed cars - which is why the eccentric bolt is called a crash bolt
Pretty common for eccentrics to move when hammering curbs at the track
I don't use them

Notso swift - what do you reckon regarding the forces at play down at the ball joint.

As long as you're using VW bolts & nuts it will be fine
Oz high tensile are a bit of a joke (unless you're talking about a class 10 bolt)

[sambb]

sorry your last post came through as I was typing mine. I'm on 5/1/2 castor. If these joints give me more than that - say 6.5 degrees, then there wouldn't be the need for camber numbers >2 degrees considering the need to get power down uphill with an open diff yeah?

[sambb]

was going to use same diameter bolts as standard in 10.9.

[Martin]

From what I can gather , by running higher profile sidewalls eg 205/50/15 my forward traction would be less sensitive to excessive camber as opposed to say 40/17's with the same camber. Do you reckon I could get away with more than 2 degrees doing hillclimbs considering the profile of A050's that I run, without hurting power down.

So many variables to think about - LOL!

Number one - I would absolutely stick with 15", no question about it
The increased weight of the 17's will hurt acceleration and braking and gyro effects
The USA SCCA guys racing under 2L FWD all run 15" for these reasons

If you go higher sidewall you will get more cornering slip angles and roll over distortion
It will force you to need even more negative camber
So again - stick with 205/50/15
Goodyear F1A2 or a Toyo Proxy R888R both have very stiff sidewalls

I have not used a A050 but I am well aware it's a high end R spec tyre

[Martin]

was going to use same diameter bolts as standard in 10.9.

I would feel safe, all good

[Martin]

sorry your last post came through as I was typing mine. I'm on 5/1/2 castor. If these joints give me more than that - say 6.5 degrees, then there wouldn't be the need for camber numbers >2 degrees considering the need to get power down uphill with an open diff yeah?

Correct - the more castor you have the less camber you will want for
At 5 & 1/2 you're doing well, if you get 6 or more it will be your shout at the bar!

I forgot about the open diff
When you start using -3 or more you can't accelerate early,
cos the inside wheel will just spin up,
you have to wait until the lean comes off the car which is often well past the apex - it can be really frustrating

This leads into another point - with an open diff you should be very aware of suspension droop
You need good droop to keep the inside tyre on the ground
With stock shocks there is nothing you can change but if you ever switch to adjustable coil overs you need to set them up for excellent droop

[seangti]

Depends

I ran -1.75 degrees on my Skoda Octavia for a few years of daily street driving
This made a huge difference to turn in performance and it did result in some featuring of the inside edge
I could also brake deep into a corner, turning and braking at the same time, it was incredible
(I have supaloy control arms - much like the Audi TT)

But from a motorsport point of view -1.75 is nothing

Thanks Martin, agree with your points. Yeah my comments are very much directed at a track centric car whereby the compromises on the street are worth it. #becauseracecar

Sam, sorry mate I can't recall what my camber settings are. I know I've got the LCA bushes for increased castor and my KMAC tops are camber/castor adjustable... but no idea of the numbers.

[Martin]

#becauseracecar

Yeah mate - love having a track/race car to play with

[Martin]

Looking at your original post and the following thread discussion (which is all good man cave stuff),
I've had two thoughts.

1) Using the TT ball joints, has that resulted in the ball joint being higher than the original unit?
If the answer is yes that would be positive!
It would enable you to lower the car by the same distance and not suffer any negative suspension geometry consequences

2) Wheel offsets for wider track?
If you were able to try a wheel with a 10mm less offset (than stock) that would give you 20mm wider track
It would give you better grip and reduce understeer
(Likely to result in scrub and additional steering feedback - both minimal)

[sambb]

I must admit looking at the joint that it might end up improving the roll centre. I've taken measurements of all my lower control arm/ball joint pivots relative to the ground so i'll be able to see if the ball joint position has improved geometry - hopefully I'm very lucky with that one. At the moment I'm just hoping big time that the ball joint will even fit the hub though!

Funny you should say that. Last time out I ran for the first time with 20mm spacers on the front and 12mm on the rear. Going by feel after trying a few widths I'm pretty certain its out in positive scrub land now and the steering didn't suffer at all, lots more feel, it didn't wander excessively under brakes and the cornering G's were way above what I'd normally be able to do. If these joints move the hub out 10mm then I'll be looking at a 30mm each side at the front = total 60mm track increase + i'll have some camber. Muy excited so really hope this doesn't fall flat.