Speedtoys

Well, its not a 'level' of driving it will impact every level of driving, even the amount of control a non driver feels that they have (or do not) over a car simply on the highway in the right conditions*, it's about correcting the geometry of steering arms if you have lowered the car from OE range where this geometry is ideal. And the fun part is that the front and rear both do it, differently...which is really REALLY upsetting.

*: Everybody has a high speed underpass or something in a highway interchange, that has a dip from something in the road, or a transition on/off a bridge in a curve the squeezes the car UP and drops the car DOWN aggressively. As smooth as a racetrack tends to be, they're not that smooth that bump steer isn't a consideration. Especially on a car with progressive springs, they will never lie flat in a constant radius turn. They can't.

The benefit is not wildly changing toe angles through a turn as the loading/suspension loading changes throughout that turn. Each axle as a wave in the surface/dip compresses the outside of the car more..toes INTO the turn a lot more, and as it rebounds from that dip/movement and rises higher than where it originally was, each axle will steer AGAINT your input.

Find the right high speed highway curves where there are mild waves/dips in the surface, and you will immediately know what was wrong with lowering the car when you get back to OE height, or adjust for it via bump steer hardware.

Lowering a car does not necessarily make a car 'handle' better, without a lot of additional work. (Bump steer, shock and total suspension travel, etc, etc...). Although without work to these new problems, you can add tire and other things, to make them less problematic. But a properly setup suspension needs fewer band aids.

https://www.motortrend.com/how-to/ct...eer-explained/

linderpat

This is spot on. So many just pop in lowering springs and their off to the races so to speak. Much more is needed to get the benefits of the changed height.

FredR

The fact that the lower control arms are the same part number both sides tells one all one really needs to know- that arm is by design intended to be horizontal under normal loading give or take a little thus the range 160mm to 170mm on a car that is settled in. When you lower the suspension to the likes of say 120mm the arm is pointing well and truly "uphill" before any movement even takes place- then take a look at some of the track cars under extreme cornering- the inboard wheel is pointing in a completely different direction [as in like 30 degrees or whatever it may be] to the outboard wheel which is more in line with the direction of travel- urrgh! Not too surprising that bump steer is an issue- just that the 928 geometry probably helps some compared to most other steering systems or so I suspect.