Ford Mustang Suspension Guide - Suspension Dimensions - Tech

Ackermann angle is also a concern on stock Mustangs. Ackermann is the steering geometry that turns the inside front tire more than the outside tire, a necessary condition as the inside tire follows a smaller-diameter turn radius. With the Mustang, Ford ended up providing reverse Ackermann, meaning the front tires toe-in slightly when turned. This can be cured with an after-market K-member, too.

All Mustangs from 1979 and up utilize a stamped-steel K-member that supports the engine and provides mounting points for the front lower A-arms. The steel construction is cheap, quick to produce, and does the necessary job for the suspension components in addition to being part of the front crash structure. But Ford has to cut costs somewhere in order to be profitable, so you don't necessarily get the best K-member that money can buy.

One may ask why the quality of the K-member might be important, and the major concern is weight. Reducing vehicle weight has all sorts of benefits, not the least of which is better handling, braking, and acceleration. The stamped steel K-member that came on your Mustang from the factory is one heavy piece, and when combined with the stamped lower front control arms, it can be a significant chunk of ballast on your already nose-heavy ponycar. Depending on the model/ year of Mustang, there could be more than 60 pounds of weight to lose. Some aftermarket K-members also offer improved suspension geometry, but as great as these benefits sound, you'll want to do your homework before shopping for one as there are many questions you need to answer before deciding if a tubular K-member is right for you.

"K-members have become a major 'wanna-have-it' item for many people," says Maximum Motorsports' Chuck Schwynoch. "This is a serious performance modification, and people buy them without realizing all of the other requirements necessary to properly set up the car with a tubular K-member. Additional items that may be needed include front control arms, coilover conversions (that require better struts), changes to the rear suspension to properly balance the car, steering-rack bushings, adjustable tie-rod ends to adjust bumpsteer, and so on."

Schwynoch also notes that while many gearheads are capable of installing a tubular front-end assembly themselves, many fail to install it properly or get the suspension adjusted correctly. "The K-member must be properly squared in the chassis, and the bump-steer must be adjusted. It's not difficult to set up the chassis, but because it's unfamiliar to many, they avoid doing it, or it scares them away from installing a K-member completely. The skills required to install a K-member are no greater than those required to install most other aftermarket performance parts. A K-member is just as significant of a performance improvement as bolting on a supercharger."

If you decide that a tubular front end is for you, Schwynoch has some purchasing guidelines and tips that you should ask yourself and the vendor. "Research the brand," he says, "and find out who designed it and where it's made. Some are made overseas, and you can't imagine how poor the quality is. Most K-members do not improve handling and are intended to only reduce weight. Not all K-members are created equal, and very few are even as strong as a factory OEM K-member, so those other after-market units are more likely to suffer damage in minor impacts.

"With the Maximum Motorsports K-member, the tires are moved forward 31/44 inch, and some large tire-and-wheel combinations, or wheels with odd offsets, may interfere with the fenders, requiring modification. Pre-'91 Fox Mustangs are mainly affected by this, and modifications are usually fairly small, requiring one to use a spreader bar to move the lower, forward part of the fender outboard slightly."