Uneven tyre wear, geometry,bushes, spacers problem..?

[Zico]

I could do with some expert opinions on my wheel + tyre setup.

The car is a Pug 106 GTI which I use as a runabout/weekend fun toy. Its now on throttle bodies, been cammed, remapped, had some light headwork, a closer ratio gearbox, adjustable dampers all round, some chassis strenghtening and much improved breathing at inlet and exhaust, it goes very well indeed now but it really needed some improvement in the grip department and a big brake upgrade was an absolute neccesity
I had the option of buying some 15" lightweight Rally style OZ racing magnesiums which have an ET40 offset, at a great price which was too good to pass up, it meant I could fit the Brembo 4-pots, bigger 283mm discs and braided hoses which I'd had lying around, due to the extra inch in wheel diameter allowing the necesary clearance for the rotors.

So basically I've went from 185/55 R14 to 195/45 R15 which has a very similar rolling circumferance, however the ET40 ? offset on the OZ Mags meant I've had to fit bolt on 20mm spacers (which the wheels in turn bolt onto) and it works out at 10mm over the original offset iirc.


The extra grip, reduced sidewall flex and of course the stonking brakes have certainly made it a very different car to drive.. obviously far more grip and outright pace at the expense of some driving enjoyment in the handling dept... simply not as adjustable on/beyond the limits of grip.

The problem is that Im getting uneven wear (on the insides) on both tyres and more recently an increasing level of understeer, also the tyres hop/judder (tracking?) a bit when reversing on full lock.. now the lower arm bushes are visably kinda ok-ish... if a bit past their sell-by date. So just a few quick questions...

1. Are the spacers most likely to be the root of my problem... or is the offset difference minimal enough to get away with it..?

2. Maybe just a case of having the tracking done to remove some excessive toe-out ?

3. Or does this sound to you to be more of a worn bushes problem ?



I've been poorly (in my opinion) advised by someone who reckons he knows what he's talking about.. to push the top mounts/chassis legs out by 10mm using the adjustable strut brace to compensate for the slightly increased negative camber !... I certainly dont want to go down this road but would really appreciate some advice on what I should be looking at doing to get this problem sorted the correct way..


Many thanks.