416tt

iTrader: (1)

I have these arms.. I don't know how much there castor adjustment will help, looks like its very minimal.. how ever figs does have bushings that allow you to adjust right from the lower castor arm..

http://shopfigs.com/v1/index.php?rou...product_id=221


Second just a FYI - if your car is lowered and you go over a bump .. these arms are really fat (tubular) and they actually hit the plates which are holding this arm.. Ill take a pic if I get a chance. I mean it makes no difference that the plates are bent now but I don't know why this wasn't seen before it was made. My car isn't super low or anything but I realize I cant even lower it more because of that :S

416tt

iTrader: (1)

those castor bushings are definitely a good idea to replace if you havnt.. I have daizens .. there design isn't as functional as figs so I plan on replacing them but did get rid of the weird wheel wandering feeling I had. front end feeling more solid and yeah my oem bushings were like soft and done...

Bgw70

Here is the installation video for the SPC 72270 upper control arms. Towards the end they show the caster and camber adjustments.
BTW, these are also for the SC430

kuWuPt

iTrader: (13)

I could be wrong but I didn't think the SPC control arms adjust caster. Camber yes but caster no, the caster is adjusted via the lower lateral arm and figs does sell a caster bushing off center if caster needs to be changed. But from past experience unless you are driving really low the caster does not need to be changed although the factory castor bushing is the cause of a lot of tire wear. I've changed mine out and have no regrets, the factory bushing was shot on almost all the lexus's I've owned. The figs bushings are on my SC, GS and IS and was definitely one of the major contributors for my tire wear.

Bgw70

Thanks for the supporting comments! You really understand the alignment geometry and process. I get the caster, camber and toe but need to educate myself more on the "cross xxxxxx" principle.

The upper control arms and lower ball joints arrived today and I am really looking forward to driving the car after they are installed with a good four wheel alignment.

Thank you all for your comments but especially mademedoit and Bon, you focused on the parts I ordered and helped me understand the best way to use the product!

kuWuPt

iTrader: (13)

I c it now, the ball joint can be placed off center to correct caster. I still think that the caster bushing itself would be the cause of caster issues. Here is a video of how much a factory caster bushing can shift over time, video also shows after caster bushings are installed.

Bgw70

kuWupt, those figs have very impressive bushings and I appreciate the video and suggestions but mademedoit is correct, I am going for the nice smooth Lexus driving experience with the correct factory specifications.
This is my wife's car and trust me, I would enjoy the tighter, more solid feel of the suspension, but she would be the typical girl and tell me it's "too bumpy" LoL
Now if she drove like Danica, that would be a different story! ;-)

kuWuPt

iTrader: (13)

Gotcha, not saying you need to do the poly bushings, you can do a factory spec bushing or replace the arm itself. I'm just saying that to resolve the caster issue the main culprit would be the #2 caster bushing. With Worn caster bushings the front wheels toe out and the caster goes negative on acceleration. This can cause uneven tire wear, vibrations, tires howling at highway speeds etc. So to get the Lexus ride quality back that is one that needs to be addressed. The SPC UCA might correct the caster issue on an alignment rack but might not bring back the factory feel on the road. Also, the biggest difference I've seen driveability vise was changing the inner and outer tie rods.
Here is the post from my build thread regarding the suspension components I changed out and why:
https://www.clublexus.com/forums/sc4...ml#post8862415

416tt

iTrader: (1)

it made quite a difference for me just changing that caster arm bushing.. before the wheels would pull me all over the place and I would have to hold the steering quite tightly.. you can always put a new oem castor arm on but knowing that it'll wear again, I would personaly just go for the poly.. I would say it would be stiff if you went for a daizen because it doesn't allow much movement at all.. But figs one on the other hand has a very functional design. (rounded middle area for movement.. The daizen upper and lower control arm bushings are GREAT and work very well... as for the Castor arm I would recommend figs for sure.

The spc arm is very good, but my only reason to get one is to get better alignment.. well camber in most case.. my new tires got destroyed ..

bgw is your car lowered at all?

Bgw70

My car is stock and at OEM ride specs.
I purchased the SLPs so the caster could be adjusted.

All of the parts are installed and I created a new thread with pictures.
https://www.clublexus.com/forums/sc4...ml#post9150699