STS spindles are aluminum. Has anyone looked at those?
I can't see the top of the CTS spindle. What is not compatible?
Unfortunately, I've checked everywhere and cannot find threaded ball joints that fit the 04-07 upper control arm. If I could, it would make things much easier. Given that, the next step is to buy a couple of 09-13 upper control arms, test fit them, and if they fit, then see if they're compatible with this STS spindle. They might not be. There's a possibility that the increased caster angle, caused by the 09-13 control arm, will cause contact between the bottom corner of the spindle and the lower control arm. The ball joint in the 04-07 CTS-V lower control arm has a limited range of articulation, and the 09-13 upper control arm is going to be pushing it.
All of this is a moot point if the STS spindle isn't appreciably lighter than the CTS-V spindle.
Would sts control arms work
Hmm, that's all I have to add to the party.
So creative steel, ready to pull another one off for us? Looks like a matched set of upper and lower arms that would allow us to bolt on a v2 spindle would be a winner. I would rather buy a set of fully assembled arms than go to the hassle of installing bushings and balljoints in my old ones....
If they're using those on the sts-v you would have to think they'd work alright for us. Maybe they had to use aluminum because they were getting close to a weight threshold of some sort.
The STS spindles don't break so I'd say the mistake was using cast iron in the CTS spindles. I never knew they were iron. I assumed the whole front suspension was the same as the STS with the exception of the caliper location.
I just bought the 2007 STS-V aluminum spindles.
I'll publish part numbers and additional information if/when I engineer a solution. I'm confident enough to put a couple hundred more dollars on the line. However, I don't yet know whether it'll require a) replacing the ball joints on the CTS-V1 UCAs with threaded ones, b) replacing the CTS-V1 UCAs with STS-V UCAs, or c) replacing the CTS-V1 UCAs with CTS-V2 UCAs.
I don't want to get you all excited, but the CTS-V iron spindle weighs 13.1 lbs, and the STS-V spindle weighs 8.7 lbs, for a 4.4 lb weight reduction per corner. If you had to buy everything new, the STS-V spindle costs $180 and the UCA assembly costs $250. Used prices are roughly 1/2 that. Compare that with the two-piece 355mm (not the 370mm) RacingBrake rotor, which weighs 21.5 lbs versus the OEM 26.0 lb rotor and costs about $400 each. Combine the two and you've lost 8.9 lbs of unsprung weight. The CTS-V1 caliper weighs 11.6 lbs (including Ferodo HP1000 pads) whereas the CTS-V2 caliper weighs 13.0 lbs (including ET800 pads). OEM and SKF X-Tracker hubs weigh exactly the same, or at least within the 0.1 lb accuracy of my scale. Therefore, net unsprung weight reduction on each corner should be 7.5 lbs.
Last edited by FuzzyLogic; 01-09-14 at 10:04 PM.