Dale Amy
September 16, 2005
With strut bodies made of polished stainless steel, and everything elseeither powder-coated or anodized in the company's purple and yellowcolors, perhaps you should order two complete KW Suspensions'adjustable-height "inox-line" coilover kits: one to install on your '05Mustang, the other to hang as automotive art on the garage wall. Fox andFox-4 owners need not feel left out--KW has coilover kits for your ride,too. And, yes, only the fronts are coilovers; the rear setup hasseparate coil and damper units.

Even if lowering a Mustang did nothing for handling, most 5.0&SF readerswould slam away anyway, mostly because Ford's corporate ride-heightpolicy seems to have been penned by some off-road truck enthusiast. That said, the search for ideal body altitude is a tough one. To theeyeball, the lower the better, but a flattering show stance just may notclear some of life's little obstacles--such as driveway ramps, railroadtracks, or frost heaves. So wouldn't it be nice if you could easilyraise or lower ride height for each and every mission? With one of KWSuspensions' new Mustang coilover kits, you can, while simultaneouslyenjoying demonstrable benefits in handling with little or no impact onride.

Though a fairly young company, established in 1991, Germany's KWSuspensions has focused almost exclusively on developing qualitycoilover systems, quickly gaining status among European race teams andauto manufacturers in the process. And while coilovers are nothing new,historically, most have been targeted at race applications. KW does havea separate, dedicated line of pure race suspension hardware butengineers its "inox-line" of coilover kits specifically for thedemanding rigors of everyday street use. This is certainly not to saythey can't be used on the racetrack--just that they're tough andcivilized enough for the environmental nightmares of the daily grind(can you say "winter"?). Part of that toughness comes from thedistinctive polished stainless steel construction of KW's coiloverbodies, employed because an adjustable-height suspension isn't worth ahoot if rust seizes up its adjustment mechanism.

On the right are the adjustable rear spring perches and their wrench.The plastic knobs on the left are used to adjust rebound on top of thefront and rear dampers.

KW's kit is also somewhat unique in that it is a true coilover kitconsisting of matched damper and spring elements, CAD-designed andsuspension-dyno- calibrated for each specific application. Moreaccurately, KW's inox-line (inox, we're told, is Euro-speak forstainless) consists of three kit variants. Variant 1 comes withfactory-fixed compression and rebound damping, carefully matched to theincluded spring rates. Variant 2 has user-adjustable rebound damping,while Variant 3--the weekend warrior's choice--allows individualadjustment of both rebound and compression.

To reach out to, and support, our side of the pond, KW Suspensions NorthAmerica has been established, and late last winter we traveled to itsVancouver, British Columbia, headquarters for a look at a Variant 3 kitbeing installed on an otherwise factory-stock '05 GT (kits for allvintages of post-'79 Mustang should be in stock by the time you readthis). Both the kit and its effect on the S197 Mustang were impressiveindeed.

Horse Sense

KW's kits are easily identified by the color of their rear damper units.Variant 1 kits use purple powder-coated rear shocks, Variant 2's areyellow, and Variant 3 kits are simply polished, because they'restainless steel.

Those New Suspenders really work, Ma

We're installing what KW calls its Variant 3 kit, having individuallyadjustable compression and rebound damping settings, as well as thespherical-bearing top mount shown here. The competition-friendly Variant3 also employs easily swappable, small-diameter, linear-rate springs(with a range of 300 lb-in to 1,000 lb-in available). The only downsideof the spherical bearing setup is that it can transmit more road noisethan the factory's rubber-encased top strut mount. KW's fixed-dampingVariant 1 kit will be set up to reuse the factory upper strut mount,which will bring along progressive-rate coils of slightly largerdiameter (in order to clear the factory mount's upper spring perch).

We measured our subject Torch Red GT's wheel arch heights in pure stockform, then with the KW kit adjusted to its lowest recommended setting,and then again in about the middle of the recommended adjustment range(our testdrive was made in this latter position).

Measured Wheel Arch Height

Stock: Front (inches) 28 1/4; Rear (inches) 29 3/8
KW Lowest: Front (inches) 26; Rear (inches) 27
KW Midrange: Front (inches) 27 1/2; Rear (inches) 27 3/4

It should be noted that Germany's insanely picky safety andtransportation agency, the TUV, tests all of KW's street kits for propersuspension operation throughout their recommended height range, so youshould have no fear about prowling around with the suspension screweddown low (other than the real fear of shearing off exhaust components orthe occasional manhole cover if your roads are as uneven as ours).

Aesthetically, and from a center of gravity perspective, KW's kitclearly does wonders for the new Mustang, but how did it perform?Unfortunately, KW North America's urban industrial setting didn'texactly provide the ideal opportunity to go all-out in handling tests,but it was a great place to judge everyday driving response and comfortlevels. Because of its enhanced unibody rigidity and revised rearsuspension design, the S197 Mustang is radically superior in both rideand handling to its Fox/Fox-4 predecessors right out of the factorydoor. But for an enthusiast, there's always room for improvement, andKW's kits seem to be one fine way to achieve it.

The kit includes wrenches to easily adjust ride height on the vehicle byscrewing the spring perches up or down (two wrenches are included--thefront and rear perches are different diameters). Those perches arestainless steel, encapsulated in composite material. This, together withthe dampers' stainless construction, should shrug off corrosion in eventhe worst of climates, allowing easy height adjustment for years tocome. The amount of thread visible here gives an indication of how muchadjustment is possible.

The Variant 3 kit--leftat its mid-damping settings as shipped from KW's German manufacturingfacility--offers a notable sharpening of turn-in and transient lateralresponse without sacrificing the S197's posterior-friendly ride. We'reguessing that the kit would also benefit a Fox Mustang's prominent pitchchanges under braking and acceleration (we'd love to try out one of thecompany's Fox Mustang coilover kits). We say this because KW's dampingcurves are notably firmer than the factory's in the lower frequenciesthat affect both pitch and roll motion. Conversely, high- frequencydamping (at least in the middle of the Variant 3's adjustment range) isfirmed up much less, explaining the civilized ride over potholes andother sharp pavement imperfections.

We're confident the same overallstreet improvements would have been gained even from KW's fixed-dampingVariant 1 kit, but the fully adjustable Variant 3 will really shine onvehicles that see some form of weekend competition, be it on thedragstrip, parking lot, or road course. Being able to individuallyadjust compression and rebound damping (in addition to settingindividual vehicle corner weights, as with all KW kits) is just theticket for racers, and the ability to quickly adjust them back for theride home from the track makes for a true dual-purpose suspensionsystem.