joemg

Since my car is still in pieces waiting for a replacement driver side header I got the crazy idea, surfing around yahoo japan in the middle of the night, to upgrade the front lower chassis brace. Since my stock one is currently off the car, I figured I'd take advantage of a free install when they button it all back up once the headers are swapped.

SlvBullet first mentioned this brace in one of his epic build threads (that car is amazing). Strangely enough, even though he mentioned the correct part number for the cusco brace, I believe the brace he actually installed was the (white) carbing brace, not the (blue) cusco brace (there's 2 pics of his in the thread below).

https://www.clublexus.com/forums/sc4...-ii-intro.html

This brace is actually a jdm part (oooOOOOOOoooo lol) for the Toyota Aristo (JDM gs300/400). Cusco part #187 477 A

There are few US sellers though, so it's very easy to get a hold of. I actually found one semi-local on offerup.

I stopped by the shop to drop it off and make sure everything lined up. The only notable thing is that it is only connected in the center of the plastic covers with 2 clips instead of 3 (in addition to the 4 bolts on the outside, so it's not going to make any difference). Also, the 2 big holes on the top of the cusco brace appear to be unused on our cars, unless they line up with something the stock one didn't when we go to close it up.

I held the stock brace, which looks ok in pictures, but it's REALLY light and flimsy in real life. The cusco brace feels like it's basically made out of slightly smaller (oval) strut tower brace type bar. I'm a pretty big believer in chassis braces on convertibles after doing a bunch of different ones on a Miata, I'm very excited to see how it feels.

Unfortunately, our rears are different than the Aristo (I think? If I'm wrong, please correct me), so the only lower braces for the sc430 rear are the ultra expensive toms racing ones that I don't think they even make anymore. If anyone knows what other braces for the aristo/2gs fit ours, I would be curious to know.

I'll take pics and report back after it's mounted just to confirm it's plug and play.

joemg

also, if you were concerned with that bright blue color as I was, you can't see the brace once the covers are on. I was going to repaint it black or something innocuous but then I skipped it since only myself or a shop would see it.

Here's a pic of our original brace, it's really thin walled and hollow, feels very light. Hard to tell from the pic.


I think our rear suspension crossmember brace (i think thats what it's called) is the same as the 2gs/aristo too. I found these on yahoo japan... no idea what, if any, noticeable impact it would have. If I end up buying anything else off yahoo japan in the future, maybe I'll give them a try for $64, but I wouldn't want to pay the international shipping for just those.

I wonder if this would fit:
https://www.r-parts-store.com/Ultra-...0-Lexus-GS-400

Harold57

Interesting. This is the same brace (OEM # 51403A) that I needed to have tightened up in an earlier thread to eliminate some pops and creaks.
https://www.clublexus.com/forums/sc4...-and-pops.html
I noticed that the middle cross bar has 2 attachment holes on the OEM versus the 1 on the blue one. Does our car utilize both or either? The diagram in the thread post #15 doesn't indicate that they are used but it is kind of hard to tell.

I'll be interested to hear whether you can tell the difference with it in versus the OEM, if you are able to tell since you are doing other improvements also.

joemg

Those are the clips. On the oem brace there are 2 on that crossbar (that you mentioned) and 1 between the top mounting points. On the Cusco bar, it only has 1 of the 2 on the crossbar (in addition to the 1 at the top). Those clips just connect to the plastic cover. The cover is held on by those and the 4 mounting bolts around the edges. My mechanic and I both agreed it wouldn't make any difference to have 1 less clip, it will still be held on firmly.


I will definitely report back once it's on. The only other mod I'm doing at the same time is exhaust which shouldn't affect handling. However, I already have a few suspension mods (front and rear swaybars, strut tower brace, door braces) so my chassis is already a little stiffer than stock.

joemg

Just updating the thread. The brace fits fine, you may have to just slightly trim the corners of the 2 braces that bolt up to it and connect to the frame on each side but it all fits fine.

First impression driving it is that it feels really tight, haven't had a chance to go on a long drive with the top down and see how it feels.

also, you can see parts of it sticking out from the covers, so if you hate the blue color then paint it first. I'm kicking myself for not spraying it black first, but I thought it wouldn't be visible.

It's under the car anyway, so the only people seeing it are me and my mechanic. I don't think I care enough to pull it off and spray it, at least for now.

I'll take a pic next time I have it on a lift.

Here's a pic before we put the side braces back on.

okievision

So much coolness under that car you're going to need to drive it upside down to show it all off!

joemg

lol thank you!


So I went for a very long drive with the top down yesterday, it's always hard to isolate the impact of a single suspension mod, because I have quite a few of them now, but the car feels so tight and precise in the corners. It's not a Miata or anything, but on twisty SoCal onramps/offramps it feels really nice. I sometimes forget it's 3800lbs now, lol.


Honestly, for $150 and a very easy install, I would say it's a pretty good bang for your buck suspension mod.

Andreiu

I'm new to this whole obscure upgrades thing - my previous project was a vanagon and the network of what to buy and where is pretty robust.

Does the SC430 2002-2005 have the same stock reinforcement? I was too nervous to lift it up on my truck stands so I could really go under it the last time I did work, not knowing where the lift points were.

How did you go about finding these parts?

I drove mine with the top down for the first time last week on these michigan highways, and it was terrifyingly shakey.

I'm pretty mechanically inclined and would love to tighten up the ride a bit with something like this and a strut brace. I was even thinking about putting in some clay and riding around with the top down to check true clearances and finding a rear brace that will fit with the top down, if even possible.

joemg

I'm pretty sure all the braces are the same throughout the years.

I did a LOT of reading and comparing pictures to come up with some of my mods.


You may want to start with upgraded swaybars, I noticed a big improvement from those (Aristo Front, ISF Rear). This brace was a pretty nice upgrade too and very easy to install. The swaybars really improved how it feels through the corners, this brace improved the overall stiffness of the chassis.


If yours is very shaky, you may want to inspect components and make sure you don't have worn bushings or some other issue. My car had 106k and while it had the usual slosh with the top down, it certainly wasn't scary.


Also, I've looked at some of the lower rear braces for the Aristo but I'm not sure if they fit our cars, I think our rear bracing is different. If anyone knows I would love to see our options.

KingReyes

I've been eyeing that Cusco brace for the longest time. Any brace will help this convertible feel more solid

Harold57

Andreiu, I agree with Joemg, if your car is shaky, there's likely something wrong with the suspension somewhere. My 2002 with over 140k miles on it is not shaky and it has the original suspension on it. (Knock on wood.) So be sure to have it inspected.

Andreiu

I'll stay on the lookout for sway bars and that aristo brace!

As far as shaky, I evaluate vehicles for a living. High speed mirror image stability is a big one and the difference that I saw from top up to top down was wildly unacceptable. Slosh would be an understatement. But also, I live in Michigan. And I'm coming from a Tacoma that when I hit a pothole in a turn, it's so rigid the backend will jump and oversteer.

It's unlikely a suspension problem, but I'll check my lower control arm bushings for slop. Everything else was spotless.

I have new snow tires on it now, so I should see any indication of suspension issues by the time I remove them.

ALSO! I saw an old post where someone found their brace had actually loosened up resulting in bad vibes and creeks. I'll be going under and cinching it down.

Lastly, anyone ever fabricate their own? I mean, it's not terribly hard to get some high strength aluminum stock tubing and swivel eye-let fittings and thread the rods. Maybe get a few plates of stock metal and drill some holes and add some cross members to the underbody?

Haven't looked at the actual underbody yet, but the drawings make it look like if you don't slam your SC, you could make some simple and affordable reinforcements for $100 on mcmaster-carr.

Andreiu

The little dog-bone chassis bracket piece that's 260mm long is common, if that's what you're asking.

digitatc

Try to get the rear ISF sway bar & front tower strut bar (cusco or the like). That will help to firm up the car for sure. Also check the shock absorber to see if they leak, if they do, change them out with KYB, OEM, Gabriel, or go coilover.

joemg

sorry, no, I meant more like this:



Here's a pic of TOM's uber-expensive SC430 brace kit, it looks like the rear braces are shaped differently.