Big Silver

I have the following on my 2000 GS 400:

L- Tuned Struts and Springs
L-Tuned Steering ECU
TRD Front and Rear Sways
TRD Front Shock Tower Brace
Toms Rear Lower Chassis Brace
18 " L Sportline wheels with Yokohama AVS Db 245/40/18's

I have noticed that on relatively fast long sweeper turns with a slight tightening kink (can you say Freeway/Beltway onramp?) that my GS seems to have some loss of yaw control - that is a type of spin rotation of the chassis.Maybe it is just accentuated with the "improvements"?

Anybody else notice anything like this??
What about a remedy?

bitkahuna

iTrader: (20)

Loss of yaw control - can you tell me what that means or what it feels like? I'm not following. I have almost the same mods you do.

DrRick

actually with the mods that you have the yaw should be more controlled. if what i think is correct, yaw is rotation of the car around an imaginary pole throught the center of the car, front to back. we normal people call it body roll. with the mods that your car has, your attitude through sweepers and hairpins should be "flatter". what you may be sensing is the tires rolling over somewhat before they take a set. hth......


Doc

redgs4

Sounds like you are describing oversteer where the tail starts to swing out on the decreasing radius turn. Tires have have the largest affect on absolute grip, but it sounds like the chassis needs a bit of front/rear tuning. Basics include tire pressure, shock/strut damping and sway bar adjustment. With your mods you may be limited to tire pressure or a complete tire swap.

One of last years Sport Compact Car had an article on how to adjust these items to get the intended result. You might also want to do a quick search, I think this was discussed in prior threads.

If you are describing body roll, then DrRick may have hit it. If you are running too low a tire pressure you may be sensing sidewall flex or perhaps even be rolling onto the sidewalls during spirited cornering.

Big Silver

Yes, it is a sensation of rotation in cornering, almost like the car rotating about an axis like a compass.

The tires are just now scrubbed at ~250 miles with correct pressure. They are also relatively low profile with much larger tire contact patch than the very poor stock 16" wheels with 225/55 Goodyears that came with Platinum package.

I can only think that it may help to go with the Tom's front lower chassis brace but there seems not to be a lot else to do.

BTW, the worst example of yaw control that I can recall in recent years was in a Chevy Malibu rental car that always felt ready to crash.

redgs4

What tire pressure are you running? I would guess you are running a bit low or that your tires are not up to the task. I run my S-03's at 40 psi, which is a bit hard but no slop.

I just had my TRD sways put on this last weekend. What I have noticed in the past few days is that the car stays level but the ultimate level of grip seems reduced. Before, the car would lean but stay firmly planted. Now the car no longer leans, but the tires break free much earlier. Don't get me wrong, I'm easily doubling my entry/exit speed around most corners from stock. And I love the way the rear breaks free, smooth, completely controlled by the right foot.

Big Silver

36 psi. I think I may be a bit spoiled in the handling department and also hypersensitive because I also have an 1800 lb. 87 CRX Si that has Tokico 5 ways, Susp. Tech. sways and Groun Control Coilovers in the rear (450 lb. inserts) that handles something like a go-kart...

I have called up Carson Toyota and think that I will get the Tom's front LCB hopefully with some improvement...

DrRick

Big,

after doing some research on yaw and reading what you were describing, the fron LCB should help. basically what you have is a rear that is somewhat stiffer than the front. in nascar, to change the handling dynamics of the car they change the sway diameter and shocks/springs. if they have a loose (oversteering) car, they lower the diameter of the sways in the front or lower spring/shock rate in the front as well. from your set-up list, you have more bracing in the back, than you do in the front, and that is giving you the feeling that the rear is coming around. if you increase it in the front, it should balance it out. but no this, nothing that you do to your GS will make it handle like your CRX.......


Doc

redgs4

Big,

Your CRX sounds like a kick to drive! Sorry, did not mean to condescend regarding your question, your first message did not mention experience in the suspension mods/tuning arena. You know what they say about assumptions.

I have a bit of front/rear tuning to do to address my own newly found oversteer.

Big Silver

Thanks, wait till you try it with the CRVTEC with ~240 HP net (in the CRX!!) - I am having to do a lot to compensate for the increase in front weight in that...

I think that Carson is going to hook me up with a Tom's Front LCB so will report on that when I have it installed. Uggh, the things we have to do to get rid of that "Cadillac" ride!!