Solid one-piece front control arms, built from 4130 tubing and Strenx plate. They're our strongest front arms. Your length, caster and ball joint setup are built into each arm when we make it, so choose them carefully. They come with the rear caster mounts.
One-piece or two-piece?
| GC GD Front Arms (one-piece) | Two Piece Front Arms | |
|---|---|---|
| Adjustment | Set when we build them, with some caster adjustment afterward | Extensive caster, some camber, easy to change |
| Strength | Our strongest | Less than one-piece |
Choose one-piece if strength matters most and you know the specs you want. Choose two-piece if you want to fine-tune your settings. See the Two Piece Front Arms guide.
Which one do I need?
1. Arm Extension
| If you want | Choose |
|---|---|
| Stock length on a GC, GG, Legacy, Outback or Forester | GC/GG (-10mm) |
| Stock length on a GD | Stock GD |
| A wider front track | +20mm, +40mm or +60mm |
| Another length | Custom, and put the length you want over stock GD in the order notes |
2. Caster
| If you want | Choose |
|---|---|
| Our standard position, 5mm further forward than stock | Standard +5mm |
| The ball joint further forward, for more caster | +15mm, +25mm, +35mm or +45mm |
3. Ball Joint/TSSPIN
| If you want | Choose |
|---|---|
| Stock geometry, with a stock Subaru ball joint, for rally, off-road, lifted cars, or track cars that don't need a large geometry correction | Ball Joint |
| A large front geometry correction for a lowered track car, and you'll fit tie rod ends that lower the outer tie rod pivot to match | TSSPIN |
4. Drift Arms
| If you | Choose |
|---|---|
| Run wide tires at a high steering angle | Yes |
| Don't need the extra tire clearance | Leave it off |
5. Lifted Ball Joint Mount Angle
| If your car is | Choose |
|---|---|
| Lifted with lots of suspension travel, on the stock ball joint | +5° |
| At stock height or lowered, or on the TSSPIN | Leave it off |
Options
Arm Extension
Every length longer than stock GD is measured from a stock GD arm. A +40mm arm is a stock GD arm plus 40mm. Stock GD is 0, and GC is 10mm shorter.
We believe GC/GG length is stock for the Legacy, Outback and Forester as well. If you're not sure which your car has, contact us before ordering.
Longer arms push the front wheels further out and widen the front track. Check that your wheels and tires still clear the fenders. Stock CV axles won't last with +20mm arms, and won't work at all with +40mm or +60mm.
Caster
The caster choice moves the ball joint or TSSPIN mount forward. It's a distance, not a caster angle: the angle you end up with depends on the rest of your setup.
Each choice is measured from the stock position. Standard +5mm puts the mount 5mm forward of stock, and +45mm puts it 45mm forward of stock.
After the arms are built, you can still fine-tune caster by swapping the misalignment spacers in the heim joints, which moves the whole arm forward or back. How far it can move is limited by the control arm pocket on the front frame, whether that's the stock frame or our Front Frame. Everything else is fixed once the arms are made.
The rear caster mounts are included. Depending on which way you install them, they add anti-dive or anti-lift.
TSSPIN
The TSSPIN replaces the stock ball joint with a 7/8" spherical bearing and our own pin, which bolts into the stock Subaru knuckle like a ball joint. It moves the outer pivot of the arm down 1.75", and is made for lowered track cars that need a large front geometry correction.
To keep good suspension geometry, the outer tie rod pivot has to move down by the same amount, or as close to it as you can get. That means fitting tie rod ends made to correct bump steer.
Ball Joint
Fits the stock Subaru ball joint and keeps the stock geometry. It suits rally, off-road and lifted cars, and track cars that don't need a large geometry correction.
Drift Arms
One-piece arms are built for strength, so the standard arm can't clear wide tires at a high steering angle. With this option, we make the arms as tight as we can while keeping them strong, to give the tire more room.
Lifted Ball Joint Mount Angle
On a lifted car with a lot of travel, the stock ball joint mount angle can make the stock ball joint bind before the wheel reaches full droop. This option tilts the ball joint mount 5° more to stop that binding. It's meant for the stock ball joint. It can be ordered with the TSSPIN, but there's no reason to.
What type of racing will you be using these arms for?
An optional note. Telling us how you'll use the arms helps us make small changes while we build them. It isn't the place for major custom requests.
Before you order
GC chassis. On a GC, part of the frame rail is in the way. You'll need to hammer it back to fit these arms.
Specs are fixed. Apart from the caster fine-tuning above, the length, caster position and ball joint setup can't be changed after the arms are made.
Transmission crossmember. Unlike our two-piece arms, these don't tie into the transmission crossmember, so they work the same with the stock crossmember or ours.
Construction
- 4130 steel tubing and Strenx plate
- MIG welded
Fitment
A front part for the GC/GD group:
- Impreza / WRX / STI 1993-2007 (GC, GF, GM, GD, GG)
- Legacy 1990-1999 (BC, BF, BJ, BD, BG, BK)
- Outback 1995-1999 (BD, BG, BK)
- Forester 1998-2008 (SF, SG)
- Legacy / Outback 2000-2004 (BE, BH)
Common questions
Can I change the caster later?
A little. Swapping the misalignment spacers in the heim joints moves the whole arm forward or back, within the room the front frame's control arm pocket allows. For bigger changes, the caster position is set when the arms are built.
Is the Caster option an angle?
No. It's how far forward of the stock position the ball joint or TSSPIN mount sits, in millimeters.
Do I need the Drift Arms option?
Only if you run wide tires at a high steering angle and need the extra clearance.
Will my stock axles work with extended arms?
Not for long. They won't last at +20mm and won't fit at all at +40mm or +60mm.
Can I get them powder coated?
Yes, as an option on the product page. Powder coating adds about 2-6 weeks. See Powder Coating.