This is an article on how to make your car handle better, it is not for the hardcore corner carver or drag racer, Also intended for the somewhat budget minded. If you are looking to make your mustang into a world class racer you’ll have to do a full reconstruction of the suspension. So for now… There is a simple 4 part method on how to make the 94-04 Mustang handle better than how it came from the factory: 1. Springs matched with Shocks & Struts 2. Lower control arms 3. Weld-In Subframe Connectors 4. Panhard Bar or Watts link 1. Springs: When choosing springs you will have to deal with lowering and harder rates, this will make your car stiffer and ride harsher. There are 2 different types of rates: Linear – same lb/in. rating throughout Progressive – Starts out as a lighter rate until compressed hard enough The progressive does ride better since it starts out at the lowest rate, and then compressed hard enough to the highest rate. When you lower your car more than 1in you are going out of the stock parameters of your alignment and geometry of the car. You can get away with 1 1/2in drop since it isn’t too dramatic. Here is a list of spring rates for stock and several aftermarket springs, drops are estimated by manufacturer. Stock Spring Rates 2003-04 Ford Mustang Mach 1 Front Springs 600 lb unique linear rate (.75 in drop) Stabilizer Bar 26.5 mm (1.04 in.) solid Rear Springs 250 lb unique linear rate (.75 in drop) Stabilizer Bar 23 mm solid (.905 in.) solid 2001 Ford Mustang Bullitt Front Springs 600 lb Linear (.75 in drop) Stabilizer Bar 26.5mm Tubular Rear Springs 250 lb/in. Linear (.75 in drop) Stabilizer Bar 21 mm Tubular 1999-2004 Ford Mustang GT Front Springs 450 lb/in. linear Stabilizer Bar 28-26.5 mm (1.04 in.) solid Rear Springs 210 lb/in. linear Stabilizer Bar 24-23 mm (.905 in.) tubular (1999-04 Bars claimed to be different thru years) 1999-02 Ford Mustang Cobra Front Springs 500 lb/in Linear Stabilizer Bar 28mm Rear Springs 470 lb/in. Linear Stabilizer Bar 26mm 2003-04 Ford Mustang Cobra Front Springs 600 lb/in. Linear Stabilizer Bar 29mm Rear Springs 600 lb/in. Linear Stabilizer Bar 26mm 1996-1998 Ford Mustang Cobra Front Springs 400-505 lb/in. Progressive Stabilizer Bar 29mm Rear Springs 165-265 lb/in. Progressive Stabilizer Bar 27mm 1996-1998 Ford Mustang GT Front Springs 400-505 lb/in. Progressive Stabilizer Bar 30mm Rear Springs 165-265 lb/in. Progressive Stabilizer Bar 24mm 2000 Ford Mustang Cobra R Front Springs 800 lb/in. (Coilover) Stabilizer Bar 28mm Rear Springs 750 lb/in. (Coilover) Stabilizer Bar 26mm FRPP B Springs Front Springs 425-530 lb/in. Progressive (1.5 in drop) Rear Springs 200-300 lb/in. Progressive (.75 in drop) FRPP C Springs Front Springs 650 lb/in. Progressive (1.5 in drop) Rear Springs 200-300 lb/in. Progressive (.75 in drop) Aftermarket Spring Rates Eibach Pro-kit Front Spring 425-530 lb/in. Progressive (1.5 in drop) Rear Springs 200-300 lb/in. Progressive (1.5in drop) Eibach Sportline Front Springs 425-630 lb/in. Progressive (2 in drop) Rear Springs 140-295 lb/in. Progressive (1.8 in drop) Steeda Sport Front Springs 650 lb/in. Linear (1.25 in drop) Rear Springs 200-250 lb/in. Progressive (1.25 in drop) Steeda Competition Front Springs 750-850 lb/in. Progressive (1.25 in drop) Rear Springs 250 lb/in. Linear (1.25 in drop) H&R Sport Front Springs 490-575 lb/in. Progressive (1.6 in drop) Rear Springs 205-250 lb/in. Progressive (1.5 in drop) H&R Supersport Front Springs 700-760 lb/in. Progressive (1.75 in drop) Rear Springs 275-300 lb/in. Progressive (1.5 in drop) Shocks & Struts: Almost anything is better than stock. If you decide to purchase them make sure they will match up with your springs, too much of a spring rate isn’t suitable for a stock or stock replacement shock/strut and will result to blowing out, for the best of both worlds some manufacturers make adjustable shocks/struts so you can set them to max for running a road course or whatever, then setting it lower so the ride home is more comfortable. There are too many combos to choose from when choosing a good spring and shock set-up. 2. Lower Control Arms: Let’s face it, Ford built the mustang for drag racing, and the control arms are designed to work great for it. When it comes to handling it is one of the worst links, there’s too much deflection since it’s covering the front to back and left to right movement of the axle. Maximum Motorsports LCA’s and Pro3i/J&M control arms are good examples that allow the axle to articulate more freely, you can also remove the quad shocks since the LCA’s take over their duty. Not all aftermarket control arms allow you do that though. It reduces your axle to feel like it’s fishtailing, I know all of us know the feeling, it’s like the rear takes a second to follow the rest of the car when turning or changing lanes. 3. Subframe connectors: Full Length Weld-In subframe connectors tie the front and rear subframes together, it reduces flex in the unibody structure, being welded in performs greater than bolt on, having to drill holes (weakening the chassis) and having the bolt support each part is ridiculous. You also want a design that fully reaches the front and rear frames. Make sure whoever is installing it has a clean contact where they weld. 4. Panhard Bar/Watts Link: They locate the mustang axle beyond the control arms capabilities of side movement. Both have very different characteristics but try to accomplish the same function, The Watts link has a better advantage over the PHB due to having a split bar design for precision movement, in which the PHB has one full length bar that moves on an arc. The PHB costs less but still performs great, the PHB will fit better with little or not modification needed, unlike the Watts. Examples of the PHB and Watts – Panhard Bar Watts Link If you shop around good enough, you could end up getting 4 components for under $1100. Pro3i LCA’s $195~ S/R, MM Subs $140~, MM PHB $340~, $400~ shocks/ springs 2 facts from the factory you could/will run into: Camber Plates - The camber plates do not allow enough room for adjustment, which will not be suitable for some lowering in all cases, most of the time you can get away with it but there are some who report needing aftermarket plates for just a seldom drop. If you have money to play with, buy a 4 bolt design C/C Plate just incase you run into an alignment problem. The Chassis – It’s all messed up, could be from old tooling to make them, how fast they needed to be produced, whatever. When it comes down to it, there are spots in the chassis where the alignment is out of wack to the point where it is bad from the get-go, some aftermarket parts like the panhard bar and rear swaybar will not fit, in which you have to do some banging to coax them in. Note: There are tons of companies out there that ‘push’ polyurethane on almost every damn suspension part, and in most cases are just selling a part with it in there just because it is stiffer and has less reaction to oils, fact is polyurethane can promote too much bind in certain locations. You are just better off leaving rubber in some parts like the upper control arms, over replacing them with poly.