I switched from the Aristo 28.6mm (hollow) front / ISF 17mm rear to Cusco 32mm (hollow) front / Cusco 19mm (solid) rear.

One note, my Mevotech endlinks had about 10k miles on them and the rubber was crumbling already. They look really nice when you get them, but I don't think they hold up well. I switched back to OEM, amayama had them for almost half price. I would have went with the FIGS adjustables but the fronts were out of stock for the next month or so. I have 25mm RCAs, so my geometry is pretty close to stock even though I'm on coilovers.

In normal driving, you don't notice much of a difference with the new bars (from the 28.6/17mm). But in the canyons/mountains its noticeable. The car is very neutral now, no more understeer. There's basically zero body roll on the street. 32mm/19mm seems like a good pairing (that's what they concluded in the past as well), TRD/F-sport uses the same diameter swaybars too. I would say the NVH increases a negligible amount, hardly noticeable if at all, if that concerns you, use the included rubber front bushings from cusco and find 19mm rubber bushings for the sc/gs for the rear (the Mark X uses ISF bushings). I went with Superpros from FIGS.


Front: Cusco 187 311 A32
Superpro SPF4441-31K bushings, 1 x Toyota 48810-30010 (LH) / 1 x Toyota 48820-30030 (RH) Endlinks
Rear: Cusco 198 311 B19
Superpro SPF2817-19K bushings, 2 x Toyota 48830-30090 Endlinks, 2 x Toyota 90179-12151 Endlink Nuts


Big thank you to Rouge who figured this out in Japan a long time ago. None of the aftermarket rear GS/IS bars fit the SC because it needs to have a slight bend to avoid some bracing (the IS350c F-sport might, but no one has tried). He found the Toyota Mark X one fit exactly. Neither Cusco bar is actually marketed for the SC430, but they do in-fact fit.
https://www.clublexus.com/forums/sc4...y-bar-mod.html
https://minkara.carview.co.jp/userid...ote.aspx#title

Note: I did not use the rear ISF/Mark X bushings/brackets, just the endlinks and nuts. FIGS is so diligent, one of the guys saw what I was trying to do on the email chain, ran down to the shop and took pics of the bushings and the subframe to show how the ISF bushings don't exactly fit perfectly.
Pics in this post:
https://www.clublexus.com/forums/sc4...l#post11872938

Side Note: I tried a 1st gen Aristo front 32mm JDM bar that I got on ebay first and they do NOT fit. I think ours fit those cars but not vice versa? they're a pinch too long.
The Cusco 32mm front bar was significantly heavier in comparison, so it worked out for the best.

Sorry, I didn't take any pics of the new bars, I'll snap some shots next time I have it in the air. Both these bars and the Cusco lower brace I have both feel VERY well made. No complaints.

(Below: Rouge's pic of the OEM sc430 12mm rear bar and the Cusco 19mm rear bar, Pnuge88's pic of the ISF 17mm bar next to the 12mm SC430 bar)
ISF rear bar thread here: https://www.clublexus.com/forums/sc4...-to-sc430.html

 

I am very happy that you found my web page about S-way bars from far away America? and realized something. That was 12 years ago, around 2013. When I was looking through the CUSCO catalog, I realized that the subtle bend was common to the sc430 and was in tune with it. I actually bought one and was convinced, so I installed it on my car. It was really strong and didn't roll at all. The suspension was genuine, so it was too strong. Therefore, I weakened it a little and replaced it with a bar of 28 in the front and 17 in the rear taken from a similar model, and since then I have been able to drive with a well-balanced sporty ride 👍 Thank you 🙋

 

This post is very timely as I'm about to pull the trigger on suspension upgrade on my '07.

Thank you!

 

Thank you for doing the research! I'm loving the new setup.

 

Thanks everyone. If you lower the car, I recommend changing the original rear stabilizer link because it is too long and the bolt holes are not the same size.
https://minkara.carview.co.jp/userid...4496/note.aspx

Rouge
Satoshi Sasaki JapanSuper Soarer Sc430 Buyeehttps://buyee.jp/item/search/seller/O2LQPWPXiNLckZ4P8VBeRA%3D%3D?lang=en Yahoo! auctionhttps://auctions.yahoo.co.jp/seller/ssk3498008 YouTubehttps://youtube.com/@supersoarer?si=8iFx2OBtLW5fj9fo FaceBookhttps://www.facebook.com/share/BuXSg4NoRmc2tNsh/

 

yes, these are the toyota endlink part numbers I listed above as well. I'm using them on my rear. They're the same as the Lexus ISF here in the US.

 

Thanks for posting this. I was looking into investing into some sway bars for the car. I am just going to run a Cusco strut bar and sway bars on my SC430. I wont be upgrading my suspension to coilovers, you still think its a worthwhile spend? Appreciate any advice on this.

 

I'm not an expert, but in all the research I did, a common theme I saw was "softer springs, bigger swaybars." and not that I've had some hands-on experience, I think this holds true. I just got my coilovers dialed in a short while before upgrading the sway bars.. Now that i've installed these swaybars, I was thinking of softening it the dampers again. I had my coilovers firmer than they needed to be to minimize the body roll, however, the sway bars are far more efficient at this task without the same negative affects. I think I can claw back some ride quality from my coilovers thanks to these. Next time I go for a ride I'll adjust the dampers on my coilovers and see how it feels.

TL;DR: I think you should be fine with stock suspension which is fairly soft. The original sway bars are tiny and the car had a ton of body roll when I first got it. If you like a less sporty feel, the 28.6/17 combo is a good oem+ option and still quite a bit bigger than the original bars.

 

I ran the experiment and my hypothesis was correct. I went 1 "click" softer on all 4 corners and the car rides like a dream and still has no body roll.

If you have adjustable coilovers, I would definitely go the Cusco swaybar route and just tune your suspension to taste.

The swaybars do fantastic job of mitigating forces on the horizontal axis without really affecting ride quality much. So you can soften up the dampers and allow a bit more motion on the vertical axis. This makes for a very enjoyable street experience.