Wheel alignment
I’ve been contemplating whether to add this or remove (as technically its neither wheel nor tyre related) and think that I’ve settled with leaving it as read. While not 100% related but it does have its links, and when I set out making this I wanted lots of info in once central place. It is a lot of info so feel free to skip down over the techy bits.
Incorrect wheel alignment will have an adverse effect on handling and also tyre wear. If you’ve not got any paperwork to support a recent alignment it may be wise to get an alignment health check.
Be weary of getting an alignment at the likes of QuickFit, etc. They’ll not be able to offer you a bespoke service and may say some elements cannot be adjusted without going to BMW. Like for example the front camber. The reality is that if the place know what they’re doing, they’ll be able to properly adjust your car. If they don’t, well do you really want them adjusting your car?
To cut a long story short, and if you’re new to the scene then a simple Z4 M alignment set up will hold you in good stead. If then you want to take things further and tweak things, then you can.
Most people want less understeer, which is inherently built into the factory setup. This is particularly apparent on non Z4 M models with so much more rear camber than front.
Front Camber
It’s reasonable to aim for maximum front camber (by pushing the pins all the way in). It will vary from car to car but this usually ends up with similar front camber in the region of 1.5 degrees plus or minus a quarter. You should then try balance the camber left and right back to whatever the lowest common denominator. For example if one goes to 1.5 and the other only goes to 1.3 get both at 1.3.
Front Toe
It's not generally advisable to run toe out on either end on the road as it's a bit too lively and not nice on the motorway with more potential for less straight line stability.
The front can be run at parallel or close to zero without any major adverse effects. It's why I often commented to aim for 0.02-0.05 on both sides.
Rear Camber
Rear camber should be in the region of 1.5 degrees plus or minus a quarter. You should then try balance the camber left and right back to whatever the lowest common denominator. For example if one goes to 1.5 and the other only goes to 1.3 get both at 1.3. You may find the stock adjustment doesn't go that low if the bushes are worn so just take the same approach as the front but aim for minimum rather than maximum camber.
If you’ve made adjustments to the front and rear camber and they end up with similar values at the front and back, keep in mind that it’s better having more camber at the front. So a setup like 1.4 front and 1.3 rear.
Rear Toe
Rear toe is the final factor then and the closer you run it to zero the more lively the rear end will be. Usual suggestion is to run a bit more than front but less than factory if you want a sharper car. With all other parameters set this is the one you could play with to add or remove oversteer to taste. I found it was not overtly lively running low numbers like 0.04-0.06. Again balance the left and right back to the lowest common denominator.
If you aren't aware the measurements are shown in minutes and seconds versus degrees. For example 2o 24 is 2.4 degrees. There's 60 seconds in each minute so 24/60 is 0.4 degrees. The numbers I mention above are in degrees so you're aiming for rear camber that reads something like 1o 15.