Kaine

Hi guys,
I recently went through some mods and the steering on the fwy is really wild. It seems as though the car wants to swirve while going over uneven patches on the road. This is only appearant on the highway. I recently completed a few mods all at once and so it is hard for me to pinpoint which of the mods have caused the problem. Your input and experience is greatly welcomed and appreciated.

Vehicle: 1999 GS300
Mods:
18" 18X7.5 +40 offset RX330 chrome wheels w/ 25mm spacers (spacers were added after the problem was noticed)
Perrelli PZero Nero 225/40/18
Tein CS coilovers with EDFC (10 threads from the bottom on the driver side and 6 threads on the passenger. This is due to the fact the CS sits 3-4mm lower on the driverside)

Any Ideas are greatly appreciated.

rominl

iTrader: (4)

ummm, did you do alignment afterwards? if youare going straight on freeway and let go of steering wheel, does it pull to one side?

Kaine

yeah, alignment is good with only a slight deviation off specs for the front camber. rear camber barely within specs. The vehicle drives straight as an arrow. i had it done at autobacs, which specializes in aftermarket mods.

rominl

iTrader: (4)

ok, so when it pulls left and right, did you notice the marks on the highway, aer those "lines" going in one direction or another?

when i had my old so3, when i change line going from different kind of ground to another, the car will pull hard. but with my pzero nero now it's a lot less, almost none. not sure youare feeling this coz' it's a big jump in suspension setup and you feel too of the road?

Kaine

OK, let me try to explain this better. Imagine going down a flat strip of highway in a straight line. You are going straight with no alignment pulls whatsoever. You then come to a less perfect patch in the highway where the asphalt is uneven. There is a slight movement of the car that in turn creates a sharp left to right ( or right to left depending on the condition of the road) movement of your body ( like your passenger ever so slightly nudges you on your right shoulder). The car is in fact going in a straight line after the movement, and actually it happens and returns to normal so fast that you really have no time to react to it unless you know its coming. The steering wheel makes no noticeable movement.

I have seen a review on TireRack that stated the Pzeros had a mind of their own on the highways. Could it be the 40 series tire?

rheiy

I could be wrong but it sounds like your describing tramline. There are a number of reviews in tire rack where people have commented about this with their Pzeros. How is the car on smooth pavement?

rominl

iTrader: (4)

and did you check the suspension bushings to make sure they are good?

my pzero nero never experiences this, umm......

Kaine

The car drives perfectly on flat and and most uneven surfaces. It only happens on certain strips of highway that i frequently take. All my bushing and control arms are in perfect order. I thouroughly checked all components prior to the mods and infact replaced the lower control arms in the front cause the bushings went bad. Never heard of tramline.

I think i'll swap back to my previous rims this weekend to see if i can't pinpoint the problem. Its nothing real serious as i can live with the problem. But if i can fix it then i'll be that more comfident at higher speeds.

Thanks Rom.

RRocket

Would tightening the steering pretensioner help???

chicagoblknazn

That might help, but we've posted on this problem plenty of times. My car does the same thing and I can't stand it. It's not the tires or anything like that, it's just the GS steering issue. Some people have tried to fix it with the L-Tuned steering ECU and some feel that has fixed the problem, and the same goes with the pretensioner, but some feel there was no change.

It's a GS flaw. I hate driving the car at highway speeds somethimes, because the car feels like it's going to fly off somewhere or under a 18-wheeler, and I have to be extra careful when really gunning it on the e-way. Our steering is just too mushy.

rominl

iTrader: (4)

good point, i do have the ecu and my steering pretensioner is indeed tightened... maybe that makes a bit difference

Kaine

Is it safe to assume that those of you who have this same problem have lowered the car? cuz prior to me putting on the coil-overs the steering was perfect.

chicagoblknazn

I noticed this last year when my car was bone stock. If anything, I feel the drop along with the low profile tires, made it a little better.

But still let me get on the eway going a good speed and the car hits a bump, a strong gust of wind hits the side or I drive next to a 18-wheeler and I feel like I am going to lose control of the GS>

rominl

iTrader: (4)

well to me i didn't have that problem putting on the 19s and lowered the car, but after i put on the so3. and then i got my steering column changed and also the ltuned ecu. and then the problem sorta went away but still there. with the new tires i don't have that problem anymore. not sure if this helps you though...

slickgt1

iTrader: (1)

Ding Ding Ding. Its the tires. I have noticed this as well when I put on my SSRs with SO3 tires. Other than this, my car is bone stock. I have a feeling that a castor adjustment would help in this issue, but ours is frozen, so we are effed.