How low until geometry and kinematics go south?

[MSY]

How low are those on coilovers going to maintain optimal track handling? I'm looking at doing an 18 inch setup with 275-35-18 which I know fits but I'm more concerned with suspension geometry changes in the arms with an inch lower than oem setuo?

Can folks give me their measurement from ground to gender or hubcap to fender? Those who have track experience and if any other suspension arm changes you did?

[M3MPH1S]

This is just anecdotal, not mathematical, but I'm on KW clubsport coilovers and I dropped about 1 inch in the front and have had no issues on the street or the track. And there's still plenty of adjustability to go lower on the coilovers, so I would think (hope) that a performance-oriented coilover would'nt allow you to go so low that you negatively affected the suspension geometry.


Edit: Forgot to include measurements

Front: 63.5 cm from ground to fender
Rear: 65 cm from ground to fender

[SYT_Shadow]

Per Bimmerworld, the lower the better

Basically you drop the car until it hits the fender liners in big bumps and then raise it a tiny bit

[MSY]

So running an 18 inch wheel such as a square 275-35-18 despite being overall lower overall diameter, and still lowering it isn't as n issue?

Syt what is your ground to fender measure?

Thinking about it, using a lower diameter wheel and tire setup than stock is equivalent to raising the car from the suspension arm standpoint right? So lowering the car I'd assume would equate to nearly the same geometry as stock setup...or closer to it then lowering with a stock overall dianeter?

I am drawing it in my head.....or am I off?

[M3MPH1S]

Originally Posted by MSY

So running an 18 inch wheel such as a square 275-35-18 despite being overall lower overall diameter, and still lowering it isn't as n issue?

Syt what is your ground to fender measure?

Thinking about it, using a lower diameter wheel and tire setup than stock is equivalent to raising the car from the suspension arm standpoint right? So lowering the car I'd assume would equate to nearly the same geometry as stock setup...or closer to it then lowering with a stock overall dianeter?

I am drawing it in my head.....or am I off?

Yeah it's close enough, you'll be fine. For street wheels/tires I'm running 265 and 295/30/19 and for track wheels/tires I'm running 275/35/18 square. Many others running this exact same setup year after year without issue.

[SYT_Shadow]

Originally Posted by MSY

So running an 18 inch wheel such as a square 275-35-18 despite being overall lower overall diameter, and still lowering it isn't as n issue?

Syt what is your ground to fender measure?

Thinking about it, using a lower diameter wheel and tire setup than stock is equivalent to raising the car from the suspension arm standpoint right? So lowering the car I'd assume would equate to nearly the same geometry as stock setup...or closer to it then lowering with a stock overall dianeter?

I am drawing it in my head.....or am I off?

This was from the floor to the bottom of the fender:

Front 25 9/16" -- 64.92cm
Rear 24 7/16" -- 62.08cm

As you see the front could use a little more lowering which I did

[MSY]

Originally Posted by SYT_Shadow

This was from the floor to the bottom of the fender:

Front 25 9/16" -- 64.92cm
Rear 24 7/16" -- 62.08cm

As you see the front could use a little more lowering which I did

Thank you very much guys!