Muscle Mustangs & Fast FordsHow To Chassis Suspension
Steeda's G-Trac Street Suspension - Proper Snake Handling
Getting A Firm Grip With An IRS Cobra Thanks To Steeda's G-Trac Suspension.
When Ford announced that its top Mustang, the SVT Cobra, would get a genuine IRS rear suspension in 1999, the news sent shockwaves throughout the automotive community. While drag racers winced and immediately figured out ways to retrofit a solid-axle 8.8 underneath, autocrossers and open-track fiends finally had their prayers answered with a suspension package that featured robust aluminum lower control arms, forged steel uppers, and adjustable toe links, all wrapped around an aluminum differential that used conventional 8.8 gears. It was a match made in heaven. Well, at least on paper.
When we took our first turn behind the wheel of a pre-production car back in late 1998, we ran it through its paces and it didn't take long to realize something was amiss. Aside from noticeable wheelhop, we quickly concluded that the IRS was lacking in response, predictability, and more importantly, traction, while applying power in a turn. After a few '99 Cobras fell into the hands of several twisty turney racers, the same conclusion was quickly made.
Luckily, Ford heard the cry and in 2003, coinciding with the launch of the much-more-powerful Terminator, it beefed up the IRS. Aside from larger 31-spline axleshafts, the biggest change was the addition of specific rate springs and aggressively tuned Bilstein shocks to control wheel movement. Going up to 17x9 wheels and 275/40/17 tires also helped, but its inherent design was still flawed. Despite the changes that Ford made, it still didn't feel right as the car felt somewhat disconnected when driven hard.
Fast forward to 2008, and we've witnessed a huge step in making IRS Cobras finally work. There are a few companies making suspension components for the '99-'04 IRS Cobras, but based on our experience, few have put together a kit that is comfortable enough for the daily grind, yet competent enough for the track, as well as Steeda has. Now we all know that Steeda is no newcomer to the Mustang suspension market, but when it comes to manufacturing its own suspension upgrades, going to Steeda is like coming home, as you know that you'll get OEM-type fit, finish, and quality.
Getting On Stage
For '03-'04 Cobras, Steeda offers three different G-Trac suspension systems-Street, Competition, and Drag. Since we wanted a more aggressive ride without excessive harshness, we kept things realistic and chose not to put a full-blown competition suspension into our Snake, as it was simply overkill for our weekend play toy. In addition, with our focus on handling, we found no need to go with a dedicated drag suspension because this car has already been running strong with a best of an 11.92 at 118.9 mph.
So, of these three choices, we went with the Street kit, which has components bundled into four complementing stages that allow a Cobra owner to install each stage separately. For instance, you can start with Stage 1, and then add Stage 2 and Stage 3 later. Then if you wanted to, you could finally put Stage 4 in the car a few months down the road. Or you can order all four stages at once, and a complete suspension upgrade can be performed at one sitting, which is how we did it simply because of deadline restrictions.
Starting with Stage 1 (PN 555-2155), we stiffened up our ride with Steeda's boxed steel subframe connectors, three-point tubular steed strut tower brace, billet aluminum caster/camber plates, and Sport Springs, which lower the car a little over an inch. This is often where many people start and serves as the "gateway drug" to better handling and fun on the street.
We then stepped up to Stage 2 (PN 555-2156), which features Steeda's polyurethane IRS subframe and differential bushings, steering rack bushings, heavy-duty antisway bar endlinks, front sway bar bushings, and superfly billet sway bar mounting brackets. For the upper rear subframe mounts, the included reinforcement kit will eliminate a lot of flex that goes on back there.