ST Suspensions Coilover Upgrade for WRX

We opted to use the largest anti-swaybar option from Whiteline – their 24mm diameter front and rear adjustable models. This is up from the stock 20mm front and rear bars. Although this is considered to be a stiff bar for a Subaru, we have used this diameter bar with a lot of success on our GD STI project car MacPherson strut suspensions do not gain much negative camber under compression. So we feel it is good to not to let MacPherson strut equipped cars to roll over much under cornering in order to prevent the outside edges of the tires from getting chewed up. If this is countered with too much negative camber, tire wear during long street commutes can become an issue.

The front bar is 2-way adjustable. The end links can be placed in either of the two adjusting holes.

The hole closest to the rear of the car is 144% stiffer in roll than stock and the front facing hole is 107% stiffer than stock.

 

The rear bar is 3-way adjustable.

The furthest outward hole is 75% stiffer in roll than stock, the middle hole is 107% stiffer than stock while the inboard hole is 144% stiffer than stock!  A cool feature about Whiteline bars is that they are a true one-piece design. The flats for the mounting holes are forged in place, not welded on.  This makes for a much stronger bar.

Whiteline supplied these ball and socket endlinks for the front bar.

These endlinks have no play in them, unlike the stock links with rubber bushings.  They are also adjustable for length so bind can be adjusted out of the bar.

In the rear, Whiteline supplied heavy duty sway bar mounts and special curved CNC machined billet end links to fit around the rear suspensions lateral link.

When running a substantially larger rear bar, stronger mounts must be used as the stock mounts are weak and will quickly become destroyed.  In fact, Ian’s factory mounts were hammered from the 22mm bar he was running.  This was rendering his rear bar less effective. He eventually replaced it with a Progress upgraded mounts before finally switching to Whiteline products this time around.

11 comments

  1. “the largest anti-swaybar option from Whiteline – their 24mm diameter ”

    Did they discontinue the BSF36XXZ and BSR36XXZ?

    1. It looks like they discontinued the 27mm adjustable bars for this chassis which is a shame because they work pretty well on big tired and R compound cars. They currently offer 22mm and 24mm adjustable and non-adjustable varients.

      1. I did some checking and the 27mm bar is still offered for the STI. I can’t think why this would not fit on the base WRX. The part numbers are BSF36XXZ and BSR37XXZ.

  2. Super excited to see where this goes! I understand that ST suspension is designed and manufactured by KW, but was there any reason other than cost to go with this over KW? Also, I remember there being mentions of some power adders in the future. Are you guys cooking up something to deal with the not so torque friendly 5-speed or swapping out to the 6-speed?

    1. We decided to try the ST coilovers because we wanted to see how well they worked for a value-priced coilover set and we are pretty impressed. We are going to try to work with the 5 speed at first but are also mulling over the 6-speed swap at a later time.

  3. Any thoughts on upgrading to STi front control arms for improved castor? I’ve done this upgrade on my car (2005 saab 92x) when I refreshed the bushings and it made a great deal of difference. Went from 3.5 degrees of castor to 5.25.

    1. I believe the Spec C front lower control arms provide 5 degrees of caster, as well as JDM 2004-2006 or 2007 STi’s provide that same degree. I’m not sure how much caster increase the USDM STi’s would give me. Also, I believe SuperPro makes a control arm/Anti-lift kit combo that adds caster as well, but I’m not sure by how much.

  4. USDM 04/05 LCAs provide 5 degrees of castor (What I have on my car). Anything newer is 3.5. I don’t know much about the JDM arms.

    I’m not sure if the 06 WRX & STi LCAs are the same or just provide the same castor, but when the WRX switched over from steel to aluminum (in sedan form at least), that’s when the STi lost castor as well.

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