jg 368 48

i've posted a lot about this and havent really, i guess for lack of a better phrase, got the info im looking for. it's not that people havent responded, but i still feel drastically undereducated in the topic of suspension...i keep searching and just not finding the right answers. here's what i want, 1 quick question...name all the parts i could buy to make my car have less of a dip effect on turns (aka body roll?) (to improve handling on turns too)? if possible, please briefly name the pros and cons of the parts you recommend. im desperate for something and want to buy tomorrow if possible!

--thanks!!

jg 368 48

also, one thing i've been recommended is the TTE lowering springs

jg 368 48

and what's the difference between coilovers and lowering springs>

Lil4X

There are a number of things you can do to reduce body roll. you can theoretically do three things, two of which are totally impractical on a production car, one of which comes with a lot of negatives.

1. Install heavier sway bars (anti-roll bars) front and rear. A modest drop and wider wheels and tires will produce some nice aesthetic effects, but don't expect your RX to corner like a go-kart. Handling may improve a tiny bit, but it will exact a commensurate penalty in ride quality.
   
   
2. Lower the center of gravity - lower the whole car rather dramatically, 5-6". May require wide-body kit and torching the wheel wells. This will be considerably more than an aesthetic body drop. To make a real difference in handling, you're going to really have to get low - and wide, which will require wider rims and tires.
   
   
3. Move weight rearward to achieve 50-50 balance. To do this may require reorientation of the engine/transmission to a fore/aft configuration. While you're at it, toss the 3.0 and drop in a small block and a six-speed. A RWD conversion is the next step in your project to make a road rocket out of a mid-size SUV. Lower the roll centers both front and rear - replace all suspension components and mounting points. A 4-bar setup in the rear would be nice - and adjustable too.

It might be more practical to buy a Ferrari, cut the body off and replace it with the panels from your RX. That's the direct approach.

The first is the only solution that won't cost you considerably more than a new Lexus, but to my knowledge, aftermarket sways are not available for the rear - the end that could probably benefit most. There is a considerable downside to heavy sways called "head-toss". Imagine driving over a speed bump with the left side of your car while thre right remains on level ground. Because the left front wheel is tied to the right with a stiff torsion bar (spring), the wheel will be less compliant with the wheel input, causing the car to rock severely as you cross the bump. The result is a sharp bit of neck calisthenics called "head toss" where first one ear then the other contacts its associated shoulder.

If you are going to drive only on a smooth track and your car will never see a pothole, you might get by with a stiffer set of springs and sway bars, but if not . . . well, it's your neck. Coilovers or air bags could be some help, but tuning for the desired effect will probably require that you purchase several sets and try them out along with a variety of settings for each. Then you'll wind up buying several hours of track time for development.

That's why most aftermarket suppliers don't offer a wide range of suspension parts for the RX. It's pretty easy to do a cosmetic drop, but to actually achieve a significant handling advantage is very complex, especially on a car that was never conceived as a sports car. There are always compromises - get the car to turn-in properly will usually make it squirrely coming out of the corner. It's a balancing act. Most people would rather spend a few bucks on a track car and leave their DD alone.

jg 368 48

so all in all, in my situation of desiring less body roll, what would u do to reduce the roll (improve cornering) where the pros outweigh the cons without spending over $600? also...i dont want new tires; i just bought new ones about 1 1/2 months ago and spent a very great deal.

--thanks!

Lil4X

Lowering springs can be a simple matter of torching off a few inches of each coil spring to bring your ride closer to the pavement. The problem with that is now you've reduced your available suspension travel, and will go crashing into the bump stops every time you hit a dip or a pothole. Good lowering springs, professionally made, are expensive - but have the advantage of being wound and tempered to provide a higher progressive rate. You still have to arrest that wheel deflection in less available space, making for a pretty rough ride in some cases, but at least you won't bottom out the suspension every time you cross an expansion joint.

As a rule, good workable suspension mods that actually produce improved numbers on the track are going to be FAR beyond your budget - several thousand dollars beyond. Bars and coilovers exact a considerable ride penalty for a tiny improvement in lap times. To produce a marked advantage requires a LOT more money than most people are willing to spend. Consider saving for an Elise - in the long run it would be a whole lot cheaper and more rewarding!

Many people associate the rough ride with improved performance, but a stopwatch is the only real arbiter of performance mods of any kind. It's not like appearance mods like a body kit or rims - the success of which are usually a matter of taste (although some mods evidence no taste at all). A louder exhaust makes you think you are producing more power down in the engine room, but fractional horsepower gains (anything under 15% improvement) seem to me not to be worth the effort and expense.

For $600, I'd just get it professionally detailed and call it good. That will produce more tangible benefit (and lasting value) than a trip to Pep Boys. Keep the change to start your Elise savings account.

tcheung87

=) me want a sporty car now

jg 368 48

ok that seems logical. so in your opinion TTE lowering springs are a waste of money? keep in mind that im not trying to gain power but changing suspension parts, rather reduce body roll (the leaning effect on turns). would lowering springs be worth that? my budget can change, but not over $1,000.

Lil4X

IMHO performance mods on an RX are an uphill battle, not really worth the money. Any SUV has two designed-in problems that are expensive to work around. First is weight. The car in AWD trim is at least 1200 lbs heavier than a small sedan - and that's a LOT to overcome, Newtonian physics being what it is. Second is all that altitude; CG and roll centers are high for ground clearance and that "macho" SUV look. Lowering it significantly will definitely change the handling, but it is not guaranteed to be for the better under all circumstances.

I can't remember the book I had on this years ago, I probably let someone borrow it

Here are a few resources:
http://www.amazon.com/High-Performan...8158967&sr=8-5

or if you really want to get serious,
http://www.amazon.com/Race-Rally-Car...8159341&sr=1-8
http://www.amazon.com/Chassis-Engine...8159341&sr=1-8

jg 368 48

i continue to post this, but i still have many questions.

i have one quick simple question.

what lowering spring is best for the following
1) improve corning
2) reduce body roll, squating, and nose diving
3) barely lowers my car (like the TTE only lowers 35mm)

what's your opinion? i hope to buy asap!

--thanks

pinoyballa

anyone got pics of a lowered rx300? im curious to see how it looks like.

aznxenon

seriously huh? slammed suv!

TunedRX300

Spring is designed to lower the car, all aftermarket springs give you 1) and 2)secondary benefits.
Eibach, TTE, and H&R all do 3), if you want someone else to notice you, then they will not be able to tell unless your car is parked next to a stock RX300.

jg 368 48

i dont want anyone to notice. i want it to look like factory, but reek the benefits of stiffer springs. so it is true that it will take away from the dip (body roll), reduce nose diving (i think tha'ts on braking right?) and reduce squating (when accelerating right?)?

i want
1. less body roll, squating, and nose diving
2. not to be able to notice a difference

does this mean springs in my case? or is there something to reach this goal better? i know about sway bars, but that's out of the question because they don't exist. so all in all, what's my best option, best brand + model + any specification i can get to achieve my goal

yeah does anyone have an pics? pure curiosity ...never seen it before

also i have a 99rx300 awd

--thanks

jg 368 48

ive also heard of shocks now...could that help with this in conjunction with lowering springs? what do they do? i want sportier suspension parts (i think)