I-FORCE

iTrader: (3)

Lets do this guys.. I have decided to venture off into improving the SC430's chassis stiffening and beefing up the handling department!

Need some advice from any Tom's Bracing pros out there...

Firstly, I have decided to place an order for a set of MeisterR coilovers for the SC, very good, bespoke product built by a knowledgeable guy for his wife's SC430 specifically; I will also be ordering a front TRD Sway Bar from the 2GS to control roll a little, and a Cusco STB to potentialy box up the front end and improve Steering feel and response.

With this setup, i should have a decent improvement up front but a near factory setup in the rear albeit coilovers. The main issue with the SC is the chassis stiffness.. The vehicle is closely related to a spaghetti especially with the top down. Dont get me wrong, the car handles pretty well for what it is but it does not give you a secure feeling per-say. I understand that this is a touring convertible not a sports car but i have reason to believe its a decent platform to work on and could be dramatically improved with the correct suspension/chassis stiffening setup.

HOWEVER... I am worried i end up over stiffening the chassis and inducing understeer. I need to tastefully mod my suspension whilst considering a set budget.

Going back to the main topic. If i were to have a good said of coilovers, a FRONT-ONLY TRD Sway-bar, and a Front STB. What can i get done to the rear in order of making it up on par with the front without over-stiffening the whole chassis?

Shall i get the 6-link setup only, or do i need to get the rear LCB as support? Do i also need to get the front? How will this help when i already should have a decent setup up front with my current vision.

Please keep in mind the braces are $687.87 a pop now, and $500 for the 6-links.

I have spent a few days reading about this on the 2GS board and all i can say is that everyone has a different opinion. Generally, people believe the Rear 6-link setup goes with the rear LCB since the 6-link stiffens up the suspension while the LCB ties the whole setup to the unibody.

Sources:-
- http://www.l-tunedparts.com/model/st...=7&model_id=27 (First 3 items)
- http://lexus.sewellparts.com/accesso...2004/4320.html (FRONT ONLY)
- http://shop.edoperformance.com/cusco...0-p-12726.html
- http://www.meisterr.com/Site/Lexus_SC430_UZZ40.html

Once i settle, i will run this setup with stock wheels and tires until i can afford the set of CE28ns i want. I will also eventually upgrade my front brakes to Supra TT 4-Pot callipers, and a rear 3.76 LSD pumpkin. The donor will be my 94 Supra TT since it is currently undergoing a 6-spd conversion surgery and will be getting a BBK to support the power it should be putting out soon

Your thoughts please.

Thanks,
Moe

SlvBullet

iTrader: (8)

Really cool. Good luck. I have the same setup in front but running on Tanabe NFS springs. Another option might be add the TRD rear swaybar but you will have to modify the rear chassis support because the GS TRD swaybar is straight and doesn't curve around it (see post with pictures). I have on my list to get the 6-link set and see how it feels. I also have to install the Supra TT front calipers. I will tell you that on the track the front felt great. I didn't notice any sloppiness in the rear but the top was up.

I-FORCE

iTrader: (3)

Thats awesome.. How does the car feel, is it more composed on corners

My main issue is steering feel, how did you feel that improvement? Did you sense and understeer at all?

I spoke to Jerrick owner of MeisterR, he believes i do not need any chassis bracing so i decided to stock to the STB, front Sway bar and the coilovers.. I'll see what that happens and save my money for the volks i want.

Regarding the rear sway bar, im not too sure i want to modify my brace bracket.. I looked at what people have done and it doesn't seem too legit imo

SlvBullet

iTrader: (8)

Yes - very good on the corners. I don't feel any understeer. I haven't want to do the rear TRD sway either for the same reason but I imagine it could be done properly with welded reenforcements. I did put the end-member brace in the rear from L-tuned. Price was right and I thought it could't hurt. I did that before I went to the track so I can't comment about the difference. I also did the daizen bushings up front for the steering and control bars.

I-FORCE

iTrader: (3)

I thought I replied to this a few days ago... Oh well.. Alzheimer's must be kicking in early haha.

Yeah I thought a lot about the rear sway bar and just decided its not worth the risk
I'm going to try the car out with coil overs, stb, and front sway at first.. Later down the road I will look into a complete set of braces

Honestly, at $1800, I would rather save up more and get the set of volk wheels I've been wanting, those alone will decrease rotating mass and give a much better stance and grip from the wider tyre..

FIGS

iTrader: (11)

I-Force, how about you try some of our RACE MEGA arms for the 2GS and toe links? I think that you will find the term "stiffening" is just going to reinforce the poor bump curve and latent un-damped springs that are your factory bushings. By freeing up the suspension with free-locating spherical bearings you allow the suspension to settle faster and the handling to happen more predictably.

If you would like to test these please let me know, we are really trying to promote the common parts this year that we are developing for the 2GS suspension including front bushings kits.

FWIW STB do very little on double wishbone cars where the shock is separate from the control arms. All you are doing is bracing the shock , which should not need bracing unless it has bottomed out. Its better to get a properly valved and sprung shock and the correct spring rate for your driving goals than to stiffen things up too much.

Mike

SlvBullet

iTrader: (8)

Mike - I still want to try those. Sent you a PM

I-FORCE

iTrader: (3)

You had to come about two days late

I just placed an order from eibach through jerrick from meisterR for complete caster/camber adj. Front upper control arms and rear camber plates.

If I understood correctly your kit replaces the rear lower control arms? Have these been tried for fitment on an sc430?

Would like some more info...

To update this thread. I have finally completed the order and decided in what I want to do. Jerrick from MeisterR is a great guy to work with and a bank of information. I ordered a set of MeisterR Europa coil overs, front upper control arms from Eibach good for 3 extra degrees of camber and caster adjustment (since my caster is already out on the front passenger side wheel), and rear Eibach SPC RCAs. I also ordered an STB from Cusco, I am not expecting much from that since I never so a great improvement from them on several cars in the past but I am desperate for some sort of steering feel improvement. I have decided to overlook chassis stiffening for now, even the front trd sway bar. Quality of roads here is terrible, I believe over stiffening the suspension will enduce wear in the rubber and majorly degrade ride quality. I am also worried about understeer. Jerrick believes the said setup will meet and maybe exceed my handling goals. I do not plan on making a track car out of the SC, I just want a good mix of everything and improved spirited driving experience. I believe the sc is a good base to work from and has potential. That's all.

Moe

FIGS

iTrader: (11)

Well perhaps you should reconsider. There are two issues there.
One, the front SPC kit as it currently is has uptravel issues since its a taller ball joint. It's ok for a very small number of people that are not running aggressive drops and tires. Camber correction on top is the wrong way to go anyway because it pushes the top into the fender and is very limited. Camber is generally not as much of an issue on the steering wheels as much as toe is on tire wear. So we make an adjustable tie rod end to reduce bumpsteer and allow you to neutralize the tire scrub. We are making a lower adjustable bushing set that is due in about 4 more weeks back from pilot as well as some negative camber upper arms for the VIP crowd. We have confirmed that the SC430 shares suspension components with the Gen2 GS.

The rear I continue to educate people of the misnomered 'RCA" that companies are selling. Because the rear is a multi-link the roll center is not affected by moving one mounting point. These so-called RCA's are just shock mount lowering devices and they add weight tot he suspension. We developed a drop kit that replaces the entire arm to do this as well as add shock leverage adjustment and sway pickup adjustment. You can see it here in our "Drop VIP kit" which we have versions for the IS300 GS 3/4/430 and SC430.


Here is the standard drop arms



The toe link is the next problem with the stock suspension as its short length creates a step toe curve during suspension travel. By adjusting toe with link length vs inner mount position, we are able to reduce the amount of rear bumpsteering when lowered and the combo of the MEGA arm and the toe link creates a balanced rear end when lowered.

I think there is a lot of things to do prior to stiffening the chassis and we have many years of testing and customer examples to prove it. Most of our drift and track guys do not have any of these upgraded braces, they seem to do fine

I-FORCE

iTrader: (3)

Interesting... Now you got me completely lost haha..

I did my research prior to placing an order.. For my usage, my setup seems to be ideal.. I do not expect GT86 handling out of the SC and i will go no where near VIP lowering level.. All i want is better shock valving, a slightly reduced ride height and camber/caster correct.. MeisterR with Eibach seemed to offer the best option. I dont understand what your offering would replace and how my current setup should affect handling.

Moe