Project GD Subaru STI Part One- Rebuilding the Suspension

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For the rear lower control arm pivot we installed Whiteline’s Anti Lift Kit.  If you just want to change bushings, Whiteline also makes a replacement rear bushing but we decided to get all of the advantages that the Whiteline kit has to offer.  The Anti Lift Kit relocates the rear lower control arm pivot point outward and downward.  This does several different things.  The stock Subaru has a lot of anti dive in the suspension geometry.  This is so the car won’t nose dive under braking with the factory soft springs and shocks. 

The disadvantage of this is that the anti dive geometry also causes lift to the front suspension when the engine’s torque is fed through the front wheels.  It also increases the effective front spring rate under braking and acceleration which might make the car understeer when trail braking and upon comer exit.  Since we are going to run performance coilovers, we will get our anti dive from those instead of geometrically.  This will give more predictable handling at the limit.  By not lifting and causing dynamic weight transfer coming out of corners, the kit will improve corner exit traction as well.  

By mounting the lower control arm pivot outward, the kit cants the lower control arm forward which increases positive caster about .6 degrees as well.  This gives more negative camber as the steering wheel is turned, increasing front grip and gives more straight line stability while improving on center feel.

Whiteline makes three different Anti Lift Kits as well, the soft Ride Comfort, the firm Performance and the hard Motorsports.  We opted for the hard Motorsports version.  The Whiteline kit is very high quality with a solid aluminum extrusion and a steel inner sleeve that perfectly matches the shape of the stock part.  Even the thrust load bearing conical inner section shown here.
You can see the difference in offset between the Whiteline part and the OEM piece.  This is how the lower control arm pivot is moved downward.
This view of the part installed shows how the lower control arm pivot is moved outward to increase caster.
To prevent the front subframe from hitting the lower control arm it is spaced downward using the provided spacers.
Although the 2005 STI has a much better steering rack and way better steering rack mounting, it can still be improved.  We installed Whiteline’s steering precision kit which replaces the squishy rubber with firm urethane.  The steel cup is a bushing removal tool.  The kit’s bushings are high quality with steel sleeves to hold the compression load on the bushings.

2 comments

  1. I have a 2004 STi. Can the hubs and steering rack be just direct replaced with an 05 sti?
    I was looking into following your project fairly closely with my car but wanted to make sure I address any issues native to the 04 to make the path easier.

    Are the engine management quirks mostly addressed once the car is tuned with something like a COBB accessport?

    1. The hubs can be but the rack cannot. However, Whiteline makes rack bushings that work well for these cars. The Access port has been pretty dialed back but is fine for OTS tunes and for strictly following Cobbs Green Initiative upgrade paths. For maintaining smog legality this is really the best way to go. For more advanced stuff ECUtek is the way to go.

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