Inexpensive adjustable rear lower control arm

[venturaII]

So, I'm still using stock springs on my 2013 FRS, and would like to keep doing so for the time being. I've got camber bolts and slightly slotted struts up front to get the camber I want, but the rear is still unadjustable with the stock arms.

I would really like to keep the simplicity and streetability of stamped steel arms with rubber bushings, but get some adjustability with an eccentric bushing (which is how these should've come in the first place, IMO).

I've found a very inexpensive OEM-style arm with an adjustable bushing, ULTRA-POWER's K100136. Just curious if anyone has used this particular brand/part number themselves? Kind of hard to screw up an OEM steel control arm, but figured I'd ask anyways.

[Spawn_Of_Creation]

SPC lower control arms are basically stock with adjustment.

Whiteline are the same as SPC, but give you an additional .5 degree of adjustment.

[kch]

Never heard of the ultra-powers. SPC is the standard for OEM-style with an eccentric bolt. I've used them for 30k+ miles and quite a few track days with no issues.

[venturaII]

I thought I'd read in a thread somewhere that the SPCs will lower the rear...is this true? That makes them a non-option for me if so..

[mav1178]

SPC works for 99% of the folks out there that don't need bling and don't need to be compliant with autocross rules.

For the remaining 1%, it's usually because they need more adjustment or they want the bling.

[mav1178]

Originally Posted by venturaII

I thought I'd read in a thread somewhere that the SPCs will lower the rear...is this true? That makes them a non-option for me if so..

SPC arms are identical to stock minus the camber adjustment + the spherical bearing.

[8RZ]

Another vote for SPC here, mine have been holding up fine.

[86league]

One other potential downside of the SPC (and I assume the whiteline) is if you are doing alignments/settings yourself without the help of a real-time display of camber and toe -- they can be hard to get dialed-in. There is some slop in the bolts/cam washers leading to a tendency to undershoot/overshoot in my experience.

That said I have about 20 track weekends using my SPC and they have held up fine.

[venturaII]

Originally Posted by mav1178

SPC arms are identical to stock minus the camber adjustment + the spherical bearing.

Whoa...glad I asked. That's exactly what I want to avoid. Looks like the el-cheapos will be the pick. Can't really go wrong for $25 a piece anyways...time to use this lifetime alignment again.

[maslin]

Originally Posted by venturaII

Whoa...glad I asked. That's exactly what I want to avoid. Looks like the el-cheapos will be the pick. Can't really go wrong for $25 a piece anyways...time to use this lifetime alignment again.

Spherical bearing, not helm joint.

Those arms look like an exact copy of SPC/Moog/etc.

The Whitelines are the same arms with the bearing pressed out and “synthetic elastomer bushings” at the inner joint for SCCA compliance.

Spherical bearing is a normal type of joint used in automotive suspension, not some huge performance upgrade. “synthetic elastomer bushings” tend to puke out every so often and have to be maintained, in my experience.

[venturaII]

Originally Posted by maslin

Spherical bearing, not helm joint.

Those arms look like an exact copy of SPC/Moog/etc.

A Heim joint is essentially a spherical bearing. Kind of like how Kleenex is facial tissue. Heim makes rod ends, standalone spherical bearings, Uniballs, etc....the word "heim" is pretty universally used when this type of bearing is referred to, especially when replacing a rubber bushing.

[smg1138]

I've been happy with the Whiteline LCA's. They're basically the same as SPC but painted silver and the bushings are STX legal.

[maslin]

Originally Posted by venturaII

A Heim joint is essentially a spherical bearing. Kind of like how Kleenex is facial tissue. Heim makes rod ends, standalone spherical bearings, Uniballs, etc....the word "heim" is pretty universally used when this type of bearing is referred to, especially when replacing a rubber bushing.

I’ve never heard a rubber enclosed suspension joint pressed in to an arm referred to as a “heim joint”.

Heim joint meaning an exposed metal bearing with a threaded rod. Like all the “racing” lower control arms.

Stock cars do not come with that style of joint on suspension. Lots of enclosed spherical joints on cars from the factory.

[venturaII]

Originally Posted by maslin

I’ve never heard a rubber enclosed suspension joint pressed in to an arm referred to as a “heim joint”.

Heim joint meaning an exposed metal bearing with a threaded rod. Like all the “racing” lower control arms.

Stock cars do not come with that style of joint on suspension. Lots of enclosed spherical joints on cars from the factory.

You are describing a rod end, not a "Heim joint", specifically. Rod ends are only radially rated, while spherical bearings are both radially and axially rated. Which I find even stranger, since the lower control arm is essentially a two force arm and only needs a radial rating, really. The axial load is handled by the toe arm. A rubber boot covering the joint doesn't change what type of joint it is, it just makes it a little more weather tolerant.

Or think of it another way; if you buy all your spherical rod ends from Aurora instead of Heim, what are they called then? Chances are, everyone still calls them Heims, the same way everyone points at a box of tissues and says "Hand me that box of Kleenex", even though they're made by Scott.