Suggested Lowering Front and Rear Suspension for DD?

[GoMax]

2015 ST - will be a DD with near daily runs around the mountain roads in Northern California.
Suspension will be BC Coilovers (6k/4k), running 15x8 TD Pro-Race 1.2 wheels & 205/50-15 Tires.

I've read many of the threads here on the forum, and plenty of the MotoIQ suspension articles.
What I have not been able to discover is a recommendations for:

how far you should you lower the front and rear suspension (via the coilovers) to optimize suspension geometry.
*Yes, optimize is a loaded word, but lets say to improve cornering while keeping the DD'ness of the car.
1/4"? 1/2"? 1"? Keep it totally stock height?

I'm less interested in how it looks, but rather what's the best DD lowered height for the Fiesta ST?
Even comments like "You can lower it up to x.x inches" without adverse effect" would be great to hear from members!

And finally, with it being FWD, is there a strong benefit to lowering the front more than the rear? Rear more than the Front?

Thoughts?

 

[GoMax]

Anyone? (Tap Tap Tap) Is this thing on?

 

[Chuckable]

Wish I could give you a scientific answer, backed up with engineering calculations, etc. But all I can offer is very basic advice based on past experience modding cars, and probably nothing more than you already know since you've read up on the subject. With our cars there is minimal camber gain in the front when lowering due to the strut-type suspension. I believe that there is no camber gain at the rear when lowering due to the twist beam suspension. So, lowering the car is probably more so for lowering the cg, and for some aerodynamic benefits. You probably can't go wrong with 1/2 inch lowering to begin with. Maybe start there, get the car corner balanced, drive it and see how you like it.