Suggestions to Improve Handling?
#17
Lead Lap
Thread Starter
^^^
Thanks for the offer, but I'll probably have either the dealer do it when I take it in for the 50K service or Belle Tire when I have them swap out the winter tires - whichever comes first. I'm seldom east of I-275 anymore.
Thanks for the offer, but I'll probably have either the dealer do it when I take it in for the 50K service or Belle Tire when I have them swap out the winter tires - whichever comes first. I'm seldom east of I-275 anymore.
#18
Lead Lap
Thread Starter
#20
Parts Vendor
iTrader: (9)
We are unaware of the before/after spring rates as well as the sway bar material.
Darrel
#21
Lead Lap
Thread Starter
Are the bushings for the sport suspension of a stiffer material than stock? I know some Cadillac DTS owners have had good luck with harder plastic sway bar bushings.
#24
First, congrats to myself on this my first post on Club Lexus.
I'm a two week owner of an '03 LS430 Parchment Ivory Pearl/Ecru w/ sport edition suspension and 17" chromies and Michelin MXV4s.
Wanna say how much I appreciate the helpful info offered here on the forum.
I'm an inveterate DIYer for the simple stuff and have so far done 3 tranny fluid D&Fs, rear differential fluid, subwoofer repair, headlights polished and powersteering fluid replaced w/ info garnered here.
I've read about the LS430's excellent engineering, execution and reliability. I really liked it from first drive. The power and luxury of the car is very nice. I was initially quite pleased that I got the 'sport edition', but after a few days the excessive understeer and ponderous sway had me searching through CL again. I was looking for a rear sway bar upgrade, but was disappointed to find out that I already had the only readily available 'upgraded' 14mm sway bar and bushings.
Anyway, looking to the aftermarket for some kind of improvement, I got these:http://www.tmengineering.net/suspens...n/make/ls.html Precisely, the polypropylene bushings for the '93 to '94 LS400 w/o air suspension. First, my disclaimer that while the front sway bar bushings are a direct replacement, the rear bushings need modification. So anybody doing this does it at their own risk.
Okay there are two problems w/ the rear bushing fit. First the hole is too small (the intended LS400 apparently has a really thin sway bar). I fixed this w/ a boring drill bit in 1/2" size. As half inch size gives a 12.7mm bore I had to work at the hole a bit to approximate the <14mm hole needed. Ya wanna do less than 14mm so the squeeze on the bar is firm once the bracket screws are tightened.
Secondly, the body of the bushing is too long. So I grinded it down w/ a belt sander to just slightly longer than the bracket, again for a firm squish on the bar once the bracket screws are tightened. This may sound complicated, but it is really self evident once you have the bushings in hand. Nice thing is that after the bushing mod, the bushing switch on this car is really simple.
I did the rear bushings first and went for a drive. How was it? In short, the body lean was much reduced. I have done rear sway bar upgrades on several cars, but the impact of this bushing change really reduced the wallow. I don't know why the effect is so pronounced, but the stock rubber bushings feel quite soft.
Then I did the front bushings. I can't really say that the sway was reduced from just the rear bushing switch alone. However, what did change was the steering feel. Originally my LS had a nicely weighted, but vague and somewhat numb on center feel. Now turn-in is notably sharper and the car finds on center much quicker when recovering from a turn.
To guard against the 'proud papa' syndrome, I had my wife drive the LS. She knew I was messing w/ the car, but didn't what I was working on. When she came back she said that "the car feels so fast that I feel a little carsick." I said that didn't didn't make sense. She elaborated that she seemed to be taking the turns faster or something.
Anyway, the car is now more fun as well safer to drive due to the improvement in handling. Now I'm really looking forward to +1 my wheels and get some UHP tires. '
I'm a two week owner of an '03 LS430 Parchment Ivory Pearl/Ecru w/ sport edition suspension and 17" chromies and Michelin MXV4s.
Wanna say how much I appreciate the helpful info offered here on the forum.
I'm an inveterate DIYer for the simple stuff and have so far done 3 tranny fluid D&Fs, rear differential fluid, subwoofer repair, headlights polished and powersteering fluid replaced w/ info garnered here.
I've read about the LS430's excellent engineering, execution and reliability. I really liked it from first drive. The power and luxury of the car is very nice. I was initially quite pleased that I got the 'sport edition', but after a few days the excessive understeer and ponderous sway had me searching through CL again. I was looking for a rear sway bar upgrade, but was disappointed to find out that I already had the only readily available 'upgraded' 14mm sway bar and bushings.
Anyway, looking to the aftermarket for some kind of improvement, I got these:http://www.tmengineering.net/suspens...n/make/ls.html Precisely, the polypropylene bushings for the '93 to '94 LS400 w/o air suspension. First, my disclaimer that while the front sway bar bushings are a direct replacement, the rear bushings need modification. So anybody doing this does it at their own risk.
Okay there are two problems w/ the rear bushing fit. First the hole is too small (the intended LS400 apparently has a really thin sway bar). I fixed this w/ a boring drill bit in 1/2" size. As half inch size gives a 12.7mm bore I had to work at the hole a bit to approximate the <14mm hole needed. Ya wanna do less than 14mm so the squeeze on the bar is firm once the bracket screws are tightened.
Secondly, the body of the bushing is too long. So I grinded it down w/ a belt sander to just slightly longer than the bracket, again for a firm squish on the bar once the bracket screws are tightened. This may sound complicated, but it is really self evident once you have the bushings in hand. Nice thing is that after the bushing mod, the bushing switch on this car is really simple.
I did the rear bushings first and went for a drive. How was it? In short, the body lean was much reduced. I have done rear sway bar upgrades on several cars, but the impact of this bushing change really reduced the wallow. I don't know why the effect is so pronounced, but the stock rubber bushings feel quite soft.
Then I did the front bushings. I can't really say that the sway was reduced from just the rear bushing switch alone. However, what did change was the steering feel. Originally my LS had a nicely weighted, but vague and somewhat numb on center feel. Now turn-in is notably sharper and the car finds on center much quicker when recovering from a turn.
To guard against the 'proud papa' syndrome, I had my wife drive the LS. She knew I was messing w/ the car, but didn't what I was working on. When she came back she said that "the car feels so fast that I feel a little carsick." I said that didn't didn't make sense. She elaborated that she seemed to be taking the turns faster or something.
Anyway, the car is now more fun as well safer to drive due to the improvement in handling. Now I'm really looking forward to +1 my wheels and get some UHP tires. '
Last edited by monkeybutt; 03-13-11 at 12:10 AM.
#25
Moderator
MB - very informative post - thanks!
#29
7% increase in diameter is considerable in its effect, dont dismiss that.
Rough calcs (not specific to the LS430, but general sway calc) gives 13mm=24lb, 14mm= 32lb.
So there would be a significant difference.. especially with the urethane bushes.
Rough calcs (not specific to the LS430, but general sway calc) gives 13mm=24lb, 14mm= 32lb.
So there would be a significant difference.. especially with the urethane bushes.
#30
Driver School Candidate
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WHat are you on, 16s? Do yourself a massive favor, skip the suspension mods until you've got the 18s on it. Night and day