[PeterWT]

I went to a well respected European Performance shop near me today to talk to them about using the PowerFlex adjustable polyurethane LCA & TS bushings to get some negative camber (~1.2*) and some more caster (~7.0*).
He recommended against using them, especially (polyurethane) for a street car. Instead, he recommended sticking with the OE bushings/arms and slotting the upper strut mounting holes. He said he's done it on many different makes/models of Euro cars. I didn't think it was possible to do that on these cars. He said he thinks it is, but he'd have to see it to be sure.
Does anyone know if it is possible? Has anyone done it?

[Joe240]

That seems exceptionally shady to me. I wouldn’t modify the body at such a critical mounting point like that. My suggestion would be to get camber plates instead or a KW kit that had camber adjustment. No telling what kind of force would be applied to that slotted area under spirited driving that could cause a catastrophic failure without proper testing first (not just “I’ve done it before so should work”).

[K8_M235i]

That's a terrible idea. The top bolts are torqued less than 20 ft lbs.

[4Hockey4]

Many have used Powerflex bushings and they work great. That sounds iffy, find a BMW specific tech IMO.

[aerobod]

Up until the latest strut design that started about 8 years ago with the 'F' series cars, BMWs from at least the E46 onwards had slotted strut towers with 3 nuts torqued to 25Nm / 18 lbft and a small factory alignment pin in some cases that positioned the strut to the mid point of the slots. It used to be an easy way to gain about 0.5 degrees camber by moving the strut top hat to the innermost part of the slots.

[Joe240]

Originally Posted by aerobod

Up until the latest strut design that started about 8 years ago with the 'F' series cars, BMWs from at least the E46 onwards had slotted strut towers with 3 nuts torqued to 25Nm / 18 lbft and a small factory alignment pin in some cases that positioned the strut to the mid point of the slots. It used to be an easy way to gain about 0.5 degrees camber by moving the strut top hat to the innermost part of the slots.

But that was part of the engineering design of the body. With the new design not having these slots, the potentially needed reinforcement for a slotted design is absent which could be a deadly modification.

[aerobod]

Originally Posted by Joe240

But that was part of the engineering design of the body. With the new design not having these slots, the potentially needed reinforcement for a slotted design is absent which could be a deadly modification.

The old design had no slot reinforcement. Not to say that the current design should be slotted, but it isn't inherently an engineering no-no with any specific risk as the hole or slot shouldn't be taking any side load anyway, the location is provided by the strut mount surface and flange nut surface friction.

[PeterWT]

Thanks for all the input.
Looking at pictures of the strut tower and upper mount, I don't think it's possible because:

• There doesn't seem to be enough space inside the tower for the upper mount to move inboard
• There are 5 holes that would need to be slotted (3 bolts and 2 location pins)
• The strut brace bar bolts to the upper mount; moving it would change the alignment of that connection.

I'm not sure why he thought he could do it.
And, if it was possible and repeatable, wouldn't lots of people have done this already? The F22 has been around for 6+years...

[Maynard]

But who doesn't love free hop up tactics, especially on a $50k euro techmobile? While you are at it, you can also drive nails through the rubber suspension bushings to firm them up nicely.

[aerobod]

Sometimes the simple solutions are the most effective, no matter the price of the starting material. If aftermarket camber plates can be fitted with the stock springs, slots in the tower will actually provide more clamping force than the designs I have seen which normally rely on M8 cap screws with a small clamping area moving in slots, whereas a flange nut with a larger surface area also clamping over slots would be a better solution from an engineering standpoint, although it doesn't look as pretty or have the cool factor of emptying the wallet to show how good the modded car and it's driver are .

I haven't had the time to look at the F22 strut tower design, but E-series BMW of all genres used slots in the strut tower from the factory to allow for camber adjustment.