twistedneck

I'm about to pull the trigger on some suspension mods on a 2012 GT BBP.

My speed shop recommends BMR variable rate lowering springs all around 1" front 1.25" rear w/o any other mods. I'm skeptical that i'll need a camber correction of some sort also.

HOwever, i have access to the regual boss and laguna coils too. I have not seen these first hand (hopefully i will today) but what is the best idea in your opinion for handling?

I think the Boss / Laguna may have a higher ride height especially in the back. I'm also upgrading to the huge Laguna 26mm rear stabar, and i'm looking for a good set of shocks that will handle high speed dips and not overheat or lose damping.

Help appreciated, this mustang this is all new to me! former VW person. alright ya'll.. thanks!!

Norm Peterson

Assuming that your car now sits at the factory preferred camber setting (which I think is still -0.75° for the '12), 1" of lowering is going to put you pretty close to the max-negative end of Ford's "acceptable" range (-1.5°). Your cornering has to be fairly aggressive most of the time to justify running that much camber, otherwise you won't be rolling the car over enough to ever get the outboard tread blocks of your front tires scuffed all the way to the shoulders. Camber plates or Steeda HD mounts plus the isolators from a '10 or earlier S197 please, don't even think of using camber bolts (maybe forget I even mentioned them).

For slightly more predictable handling, get linear rate springs rather than progressives, or springs with less progression rather than more. Especially for the rear springs, because you have to wait for the rear of the car to actually start doing anything 'iffy' before you can start to correct for it.

Koni "yellows" are a good damper upgrade. Beyond that are AST (at over double the $). Probably others further up the food chain too.

A 26mm rear sta-bar sounds positively huge - is there going to be any drifting in this car's future?

You may want to touch base with Sam Strano (stranoparts.com, site vendor).


Norm

twistedneck

Ok i spoke with some people in the know about the spring and bar pkg on the boss and laguna. biggest difference between the brembo pak is rate, the rates are much higher in the rear and higher in the front. also, they have larger rear bars.

as you know stock coils are not variable rate. i do understand what you are saying about linear better but with rate that high coils can come loose at rebound height. thats probably the main driver for the variable rate.

I'll call Sam for sure but i'm thinking a higher rate set of stang coils will do the trick. the oem ford boss / laguna parts do not do much to ride height.. but the check load on the front coils is greater for some reason on the big boys - not sure why, maybe because the rear end is jacked up - the big change from brembo tune to the others seems to be the emphasis on front grip, like you said maybe they wanted to make a drift car, hell that sounds really cool.

all of this leads to damping, so i'll need the koni yello's as you stated. Thanks!!! any more feedback is appreciated.

Norm Peterson

I'm thinking that the difference between "much higher in the rear" and just "higher in the front" may have been done for flat ride reasons. I know I've seen mention of some "hobby-horsing" on the forum, which is a front/back head toss or pitch issue.

On a competition car you can quiet this down with enough damping, but since "enough damping" would likely bring on harsh ride complaints from the average buyer it's still better to get the basic front and rear ride frequencies matched better. Maybe even more important for a car that's already more stiffly sprung?


Yes, either a progressive spring or what I call a "bilinear" spring (with only two discrete coil spacings and uniform wire diameter) is what you're in for with stiffer springs that are short enough to potentially fall out of the perches at full droop. Similar to what you do with coilovers with two separate springs per corner run "in series". It's either that or adjustable perches of some sort a la NASCAR and circle track, neither of which is likely to make the cut as OE or "off-the-shelf lowering" products.


Norm

Sam Strano

BMR springs... you should pass, quickly unless you want softer than stock springs. Boss springs aren't all that special either. A little stiffer than stock GT springs, but very little and still too stiff in the rear like other "normal" GT springs.

And the 26mm rear bar is huge (and too big) as are the 25mm bars from the normal Boss, and even the 24mm bar that's stock. The FIRST change I made when I could was to switch the rear bar to an adjustable 22... and I don't even run it full stiff.

twistedneck

Ahh reality sets in

ok i do get it now. thanks for the excellent help. 25mm bar it is.. i can always try a 22,23,24,or 26 later since i have access to the assemblyies.

now, for a stiffer lowering spring and camber plates - Sam do you have both? i do NOT want soft loweing springs i want something real stiff as this is not a daily driver and i want to know its serious i dont care about bumps or spider crack sensitivities. what coils do i need and do you carry them?

Stiff = good for me (i.e. high rate) and thank GOD i didn't get the pillow soft BMR's.

twistedneck

I finally spoke to Sam. Wow that was enlightening! Thanks Sam... i'm picking up the higher rate front bar, steda coils, koni sports, steda hd mounts for camber correcting.. and i'll need to get 2005 to 2010 Ford strut mounts for the small isolator piece. did i miss anything?

and the one thing i was SURE i was going to do - get the 26mm Laguna rear stabar.. not happening i'm leaving the stock 24mm bar on!

Thanks for the help ya'll!