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Sigma front control arms

Posted: Wed May 20, 2009 6:59 am
by JD_Stazza_Brendan
Does anyone know if Sigma (RWD Aussie ones) front control arms are the same as Starion. Everything else in the front seems to be interchangeable.

Kicking myself i didn't take the ones from the parts car. :x

Posted: Wed May 20, 2009 8:36 am
by dirtygalant
As far as I know they are. Not everything in the Sigma is the same though - the sway bar is way different mounting through the castor rod to chassis mount on the Sigma whereas Starion had a sway bar on its own mounts further back towards the crossmember. The brakes are different also.

Posted: Wed May 20, 2009 8:44 am
by JD_Stazza_Brendan
I know its not all the same, But it seems like everything is interchangeable between the 2. Even a Sigma swaybar will fit onto Starion so i read somewhere on here.

If the control arms are identical (length wise is my concern) ill get a set from wreckers so i can clean them up, paint them and rebush them.

Posted: Wed May 20, 2009 9:20 am
by dirtygalant
yeah Sigma sway bar will fit in Starion, there is the raised section and nuts welded in ready for mounts to bolt there, but why would you want to run a Sigma sway bar? As far as I know they don't come bigger than 24mm, and the leverage point is further back than the Starion one and wouldn't be as effective as a Starion 24mm or even a 21mm sway bar.

Sigma control arms should be the same length as Starion flatbody.

Posted: Wed May 20, 2009 9:51 am
by JD_Stazza_Brendan
might bite the bullet and get some. Wreckers is cheap here anyway.
Anyone got a control arm off a Starion they can measure so i can compare to Sigma one.

Posted: Wed May 20, 2009 4:12 pm
by panda
Can anyone either confirm or deny whether the camber angle, that is the angle between the strut tube & the stub axle, is the same for late model Oz Sigma (GJ ~ GN) & N/B Starion.

Posted: Wed May 20, 2009 5:46 pm
by dirtygalant
Sigmas definitely have more positive camber but I think this is due to where the strut tops are positioned compared to Starion.

Posted: Wed May 20, 2009 9:27 pm
by enthuzed
JD_Stazza_Brendan wrote:might bite the bullet and get some. Wreckers is cheap here anyway.
Anyone got a control arm off a Starion they can measure so i can compare to Sigma one.

Approx 280mm from the end of the pivot point to the first set of ball joint assembly mounting holes. Give or take 1mm as it was measured from the top side and the tape measure gets bent a bit in the measurement. Brendan, you'll have to pull an arm off a Stigma or at least swing it down so you can take a measure of it.

Posted: Thu May 21, 2009 2:39 pm
by panda
dirtygalant wrote:Sigmas definitely have more positive camber but I think this is due to where the strut tops are positioned compared to Starion.
Ah ! that might explain something. Recently I fitted some Starion struts to a Sigma auto-cross car, but found the camber shifted. We corrected this camber by building some custom control arms, 30mm longer than standard Sigma. We then added some 25mm spacers to the rear wheels to keep all the wheels in track. Don't know if any of this is legal for street use. :? Also we found that the Starion strut tubes are 8mm shorter than the Sigma strut tubes, thus preventing any easy swapping of shocks. :(

Posted: Thu May 21, 2009 7:34 pm
by dirtygalant
both Sigma and Starion have the same KYB insert part number listed, so the strut lengths should be the same?

If you put Starion struts into a Sigma with the Sigma top hats in the same position (you can rotate them around to change camber by about 2deg) and had a noticible difference in camber then it would suggest Starion does run more negative camber on the sub axle.

Posted: Thu May 21, 2009 7:47 pm
by S0LJAH
some of the model sigmas had arms the same length as starions
other ones are shorter

you guys are messed up in oz with ur models as theres heaps and its shit only you got
i think it is the late model oz ones (no idea what model there called) that are the same
but most of the sigmas here in nz have the starion length arms as there jap spec models

long arms plus starion struts = neg camber for me

guys who have used the shorter arms also had the problem u described
i assume you put them into an early model car (hopefully?)
it is due to the angle of the stub axle i believe
so you just need the long factory arms


i looked into it wen i was doing the starion front strut swap in my car (lancer)

Posted: Sat May 23, 2009 10:45 am
by sigmaproject
GN Sigma front sway bars are 26mm

I have Starion Struts in my Sigma using the stock Sigma 4 bolt top mounts and stock bottom arms. Machanic didnt report any difficalty getting the alignment to spec.

The Starion brakes add 6 mm to the front track compared to stock.

I also stuck some 30mm bolt on spacers on the rear to get the front and rear tracks similar.

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