L-Tuned & Alignment Problem
07-23-01, 02:09 AM
#1
Lexus Test Driver
Thread Starter
I am having some alignment problems and hope a couple of members who have a similar setup as my GS430 can help. My GS430 has L-Tuned Shock/Spring/ECU with Lowenhart BR5 18x8.5" (S03 245/40R18) and 18x9.5" (S03 275/35R18). Since my modification with is 1.5 months now I had already two alignment done by the Lexus dealer and on monday next week I am having them align it again. The problem is there is a constant scrubbing sound and twitchy steering on high speed turns. The service manager is a great guy and is covering all these realignment under warranty therefore no cost to me to have the car realign again. Also they just received a new 3D alignment system.
What I am looking for is what are the specs does everyone use to have their car align with after the L-Tuned modification and stagger wheel size?
The last alignment reading I have is as follows.
L-Caster: 8.5 R-Caster: 8.9
L-Camber: -0.7 R-Camber: -0.7
LF-Toe: 0.15 RF-Toe: 0.15
LR-Camber: -1.0 RR-Camber: -1.1
LR-Toe: 0.20 RR-Toe: 0.25
Total Toe: 0.30
Thrust Angle: -0.0
If you have a copy of the alignment report please post them.
Would appreciate any assistance.
Chu
What I am looking for is what are the specs does everyone use to have their car align with after the L-Tuned modification and stagger wheel size?
The last alignment reading I have is as follows.
L-Caster: 8.5 R-Caster: 8.9
L-Camber: -0.7 R-Camber: -0.7
LF-Toe: 0.15 RF-Toe: 0.15
LR-Camber: -1.0 RR-Camber: -1.1
LR-Toe: 0.20 RR-Toe: 0.25
Total Toe: 0.30
Thrust Angle: -0.0
If you have a copy of the alignment report please post them.
Would appreciate any assistance.
Chu
07-23-01, 06:25 AM
#2
Lexus Fanatic
iTrader: (20)
Chu - real sorry to hear of the problems you're experiencing.
Perhaps it's not an alignment issue though, and is related to the problems others have had with the L-Tuned shock bushings being used instead of the original ones? I've heard this can give noises especially on the 430.
Perhaps it's not an alignment issue though, and is related to the problems others have had with the L-Tuned shock bushings being used instead of the original ones? I've heard this can give noises especially on the 430.
07-23-01, 01:18 PM
#3
Lexus Test Driver
Thread Starter
Hi Bitahuna:
No the sound is not from bumper but from the tire scubbing sound. I had the stock bumper installed rather than the L-Tuned one. I believe there is too much postive toe setting and too much negative camber. When I look at the specs for the caster it was too positive and the dealer said because the car was lowered the geometry is different and they could not get the caster to spec. They also put more negative camber for better handling.
I feel the handling of the L-Tuned GS430 is not as good as my previous stock 1995 SC400. To give you an idea there is a particular right turn curve road that lead to a steep uphill. On my SC400 with stock spring/shock but with 17x8 and 17x9 rims I could drive through this curve at high speed (80 to 90 mph) and the car handling is very neutral. I tried this road on the GS430 this weekend and during the middled of the curve my car twitches to the right (almost like oversteering) then as I reduce the throttle and a quick short steering turn to the left to correct the steering. My guess it may be the alignment or probably the tire side wall flexing. I run my tires at 36 psi cold.
Another problem is that at high speed the car feels floaty when I high a bump on the road. A bit uneasy feeling. But still better than the stock spring/shock. But not as good as my 1995 SC400. It make me wish I had gotten a stiffer shock and springs combination. I guess it has to be a trade off for comfort and handling on the L-Tuned.
A friend of my told me I may need to get a anti-sway bar. What do you think?
Chu...
No the sound is not from bumper but from the tire scubbing sound. I had the stock bumper installed rather than the L-Tuned one. I believe there is too much postive toe setting and too much negative camber. When I look at the specs for the caster it was too positive and the dealer said because the car was lowered the geometry is different and they could not get the caster to spec. They also put more negative camber for better handling.
I feel the handling of the L-Tuned GS430 is not as good as my previous stock 1995 SC400. To give you an idea there is a particular right turn curve road that lead to a steep uphill. On my SC400 with stock spring/shock but with 17x8 and 17x9 rims I could drive through this curve at high speed (80 to 90 mph) and the car handling is very neutral. I tried this road on the GS430 this weekend and during the middled of the curve my car twitches to the right (almost like oversteering) then as I reduce the throttle and a quick short steering turn to the left to correct the steering. My guess it may be the alignment or probably the tire side wall flexing. I run my tires at 36 psi cold.
Another problem is that at high speed the car feels floaty when I high a bump on the road. A bit uneasy feeling. But still better than the stock spring/shock. But not as good as my 1995 SC400. It make me wish I had gotten a stiffer shock and springs combination. I guess it has to be a trade off for comfort and handling on the L-Tuned.
A friend of my told me I may need to get a anti-sway bar. What do you think?
Chu...
07-23-01, 01:52 PM
#4
Lexus Fanatic
iTrader: (20)
Interesting. First off, I'm not surprised you feel a stock SC400 handles better than an L-Tuned GS430. I expect the GS430 weighs 500lbs more and definitely has a higher center of gravity. Also, I don't know what rims you have on your GS. If you only have 16s, the tire flex is terrible on hard cornering. The 17s are better, but 18s will be even better. I also have the TRD sways, and front STB and replacement LCB so the handling is plenty good enough for me, although it could always be more capable.
For comparison I went out with a guy in his stock IS300 for a fast rip through a parking lot area at the last meet here in Atlanta, and did same with my modified GS400. I found them to be pretty similar in capabilities, although of course the IS is a lot lighter. You'd think with my mods I'd win, but the stock IS300 is really setup nice and the car is short with short overhangs.
As far as alignment, I don't know what my dealer did after installing the L-Tuned, but I was certainly happy. Are you sure the dealer is setting to where it should be? How do you know the caster is too positive? Maybe Steve Ganz at Carson has the correct specs for you to compare.
Hope that helps.
Just got my Tom's rear STB today - looks cool! That will complete the picture on my car (for now
).
For comparison I went out with a guy in his stock IS300 for a fast rip through a parking lot area at the last meet here in Atlanta, and did same with my modified GS400. I found them to be pretty similar in capabilities, although of course the IS is a lot lighter. You'd think with my mods I'd win, but the stock IS300 is really setup nice and the car is short with short overhangs.
As far as alignment, I don't know what my dealer did after installing the L-Tuned, but I was certainly happy. Are you sure the dealer is setting to where it should be? How do you know the caster is too positive? Maybe Steve Ganz at Carson has the correct specs for you to compare.
Hope that helps.
Just got my Tom's rear STB today - looks cool! That will complete the picture on my car (for now
).
07-25-01, 10:03 PM
#5
Moderator
Service Rep here in Austin, contacted TRD and the answer given to him was "use the same alignment specs as specified for stock".
Salim
Salim
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