SN95 Coilover Spring Rates & Options

[Doc Hawk]

02 GT Vert. Rolling on 18" rims from an 06 GT, spaced for proper fitment. Other than a Steeda front strut tower bar from one of WS's awesome members, the car is bone stock.

I want to get rid of the massive body roll on turn-in, and get her handling in the twisties. This is really my wife's car, so I need to preserve a little ride quality, but the stock suspension reminds us of a Crown Vic more than a sports car. Overall I'm looking for a much firmer ride without going full race. A second objective is to get rid of the massive fender gap, so I am looking for a roughly 1.5" drop.

Coilovers look like the way to go for me, but despite searching extensively on MustangForums, ModdedMustangs, AllFordMustangs, and Corral, I have not found a good straightforward writeup on recommended equipment. I see a lot of talk devoted to quarter mile times, but few people talk about cornering performance, which is all I am after. When people do talk about UPRs, Eibachs, etc, they really don't seem to know that much about suspension tuning, they are just street enthusiasts throwing suspension parts at their cars. They certainly don't understand selecting spring rates, matching struts to springs, or dynamic weighting.

I am thinking MM CC plates but after that I don't know what CO setup to run. Are there any actual experienced road race or HPDE drivers here who can give me a little insight on a good adjustable setup to get 1-2" of drop and flatter cornering without making the ride knock your teeth out on the street? Any insight or pointers to existing threads greatly appreciated.

Regards,
David

 

[sdsubzero4]

Put a full length subframe connector and a roll bar and a strut tower brace since you will be doing more twisties. But to get rid of the twist and turn on the body, the subframe connector and a roll bar is a good start.

 

[94riogt]

With coilovers it can get tricky, I have read and reread all the write ups on the maximum motorsports website and others in attempt to understand the mustang suspension better. Now let me just start right out with it.... Coilovers will NOT improve your cornering ability very much. All a coilover suspension allows you to do is the primary advantage to ussing a coil over strut setup instead of a coil and strut is that you can run much lower spring rates but the leverage advantage allows them to behave as if they are much higher, without sacraficing much if any ride quality. Coilovers do offer handling benefits from the added leverage and superior location of the srping, but due to the fact that this is your wifes car used for daily driving they really wont be that noticable over just a lowered car with struts.

Now the advantage from the coil spring is the ability to run a much higher spring rate without getting a rougher ride.... high spring rates (up to a point and when paired with the correct struts) = better handling

By moving the spring directly to the strut you can use seemingly much lower spring rates and still get better handling.
For example most aftermarket lowering springs range in spring rates from 600lb all the way up to 850lb depending on what they are intended for, usually you will find H&R and other race oriented springs in the higher range and springs ment more for ride quality and cruising in the lower range. Coilover spring rates are much lower ranging from around 150lb up to about 400lb's. To compate the two you have to convert them to wheel rates, I cant remember the conversion just off hand but if I remember correctly a spring around 800lb's mounted in the stock location has about the same characteristics of a coilover spring that is only about 175lb's. DONT take that as fact just use it as a reference to give you an idea about the difference.

Now all of this references the front of the car, coilovers in the back of the car are completely different.

I run coilovers on the front of my car and they are AWSOME, the ride quality is amazing, the ability to change ride height on the fly is a huge perk and plus its just plain cool to say you have coilovers.

Now for my opinion:
Just to give you some outright setups to take a look at that you might be happy with

This is what I have on my car now and it is pretty good, absolutely PERFECT for a street car with good manners:
Front:
Tokiko Illumina 5-way adjustable struts
MMR coilover kit with 300lb spring
Steeda CC plates (Go with MM if you can, I got these plates for a great price so I couldnt pass umm up)
Saleen K-member brace
factory strut tower brace
Kenny brown weld in subframe connectors
Steeda bumpsteer kit (a must if your lowering your car to improve ride and performance and not just for looks)
Rear:
Tokiko Illumina 5-Way adjustable shocks
H&R super sport rear springs, 300lb
Steeda adjustable rear sway bar
MM tubular lower control arms

Like I said this is the setup I run and I am happy with it, however you CANNOT run coilovers on tokiko SHOCKS, so keep that in mind if you decide to go that route. They are a great shock and I have no complaints, but my car is being built to compete in SCCA solo events and maybe some road racing later on down the road, so im going to be switching to some Koni Yellow SA's in the rear with custom valving and coilovers. Aswell as a panhard bar and torque arm.

This is what I think you should get for your wifes car and build from there:

Weld in subframe connectors (this is a MUST and an even bigger MUST since the car is a convertable)

If you want to spend a little extra money and get a real performance set of dampers I would say go with Tokiko Illumina's, or Koni SA's. Bilsteains are great aswell but the fact that the tokiko's and koni's are adjustable really make me recommend them more (adjustbale meaning you can make the ride firmer or softer)
Now if you want a good set of dampers that will offer a good ride, but wont quite be up to the performance level of the previously mention dampers I would say go with some Koni reds or KYB AGX's. I have heared good things about both of these dampers for the price, I would definitly say Koni over KYB though. Also take a look at the tokiko blues.
If your going to run coilovers however you will need to get one of the higher quality dampers from Koni, tokiko, or bilstean as they are the only ones that have strong enough valving to handle a coilover setup.

caster camber plates
lowering springs (try just these out first before you make the leap to a complete coilover suspension)
bumpsteer kit

Ive got a bunch more I could write but my fingers are tired, haha. But feel free to ask any questions or correct any mistakes I made, I am in no way saying I know it all and im sure there are some guys out there that know a billion times more then me, but I hope this helps!:rock: