My GS430 is deficient in expressway directional stability. It wanders, requiring constant correction in order to stay on course. Both with original 16" tires/wheels and present 17". Inflation pressures at specs (33 PSI). It does not pull to either side, it just wanders. In moderately gusty winds, it becomes a real chore to drive.

It's as though it's short on caster, but returnability in exiting a slow speed turn is excellent.

Background: I had a 1997 Lincoln MKVIII that had no idea where 'straight ahead' was ... it was a constant battle to keep it on course, even with 4-wheel alignment to settings recommended by Ford engineers. My 430 is far better than this.

My most recent car, prior to the Lexus, was a 2000 Lincoln LS. This car was laser-straight, requiring minimal steering wheel input in order to stay on course. Wind gusts had little effect on this car. My 430 is significantly worse than the Lincoln.

Has anyone experienced a 'wandering' GS430? If so, were you able to get it corrected, and how was that accomplished?

 

The GS is notorious for wandering, especially at speed, with the stock steering ecu (and if the alignment is out of spec).

I suggest an alignment and installation of the L-Tuned steering ecu. They will significantly improve your steering. You can get the ecu for about $125 from from Steve Ganz (SupraTD).

And don't listen to those who say the 430 already has the L-Tuned ecu. It doesn't. Bitkahuna and I tested the stock 430 ecu vs the L-Tuned version and they are NOT the same.

 

Drive4fun - hard to have fun or track straight on those roads in Michigan. More ruts than an ice floe.

 

I have the same problem with my 98 GS400 and I have the L-Tuned suspension and steering ECU. I've never owned a car that wandered so much (I believe it's called "tramlining". Someone mentioned that low profile tires cause this but none of my other cars (MR2, Talon, etc) did this. The dealership did an alignment as part of the installation on the suspension.

When I'm driving on a road with any ruts, I really have to pay attention to the steering wheel or it'll try to change lanes on me.

 

My GS has absolutely no problem with direction stability.

 

When I got my car, it wondered as well. The car was riding on the stock RE030 tires. I changed them to Michelin pilot XGT Z4 and the problem solved. Right now I'm using Yokohama AVS dB and no problem as well.

 

I sincerely appreciate the input; please continue.

I know what tramlining is, and this is NOT tramlining. My wandering occurs on smooth, un-rutted concrete expressways ... the same ones on which my Lincoln LS was laser-straight.

I'd like to learn more about the L-tuned ECU. Does it increase the steering effort? If so, it seems it would make an inherently unstable situation more difficult to deal with.

 

Tramlining my cause wandering at speed if the road is grooved, but it's not the same as the wandering on my GS400. My experience with tramlining is that it's primarily a function of your tires. The OEM Potenzas were the worst tramlining tire I've ever driven. They would track bird droppings in the road.

I switched to Michelin XGT/Z4s on my 98 GS and the problem disappeared completely. But it still wandered on the highway since I never upgraded my suspension or ecu on the 400 before I got the GS 430.

 

The L-Tuned ecu increases steering effort marginally. What it seems to do is lessen the boost from the power steering and reduce the play in the wheel. And the car is much easier to control on the highway. Not exactly sure how it does it, but it works. I suggest you install it and see if it solves your problem. If not you can pull it out and I'm sure you'll find someone else on the site you can sell it to.

 

I've heard about this wandering, but I'm not aware of ever experiencing it, either with the stock setup or my heavily modded one now.

 

It depends A LOT on how a person drives. On the expressway, with little traffic, I hold the wheel with left thumb & forefinger at about 8:00 o'clock.

 

This also happens to my SC400. It was fine until I upgraded the rims and tires to 235/45/17 and 255/40/17 on Yokohama A520.

Maybe I should change my tires to Yokohama AVS dB and see what the outcome is.

Also, will L-tuned suspension and steering ecu fit in my SC400? I have '95 SC400.

Thanks,

Peter~

 

I have similar problem in my GS400. I did change steering ECU and installed L-Tuned shocks, which made the situation better, but it is still not as stable as I would like it to be. Its not too bad up to 85mph, but then it really starts to wander. I had BMW 528i before and it was like the train on rails at any speed. I did test drive Lincoln LS with sport package and it did feel more stable then my GS.

 

I was really frustrated with drivability of my GS until I got the Yoko dB's. What a difference. They may not be the highest performance tires, but after Bridgestone (wore out too quickly, wandered all over, and really sucked on wet roads) and Dunlop(never got 'em balanced well, eventuallybubbled and split), I'll stick to these.

I've been tempted to try the ECU, but don't need it with these tires.

 

Where in Michigan, i'm actually in Ann Arbor.

Albert