bacek

^hmmm this is confusing.... so how can one tell if the bushings are shot?

i always thought the way to tell if the busings are worn is if all of a sudden the back end starts to step out mid corner when the load is greater not on initial turn in. for reference i rarely lift-oversteer and sometimes when cornering hard my back end starts to slide unpredictably instead of progressively as i open up the throttle. am i just a bad driver lol?

i might be understanding something wrong here.

ps. please dont flame me because most dtss info ive read on here is not that helpful ie."if you want to drift eliminate the dtss" etc. no real technical discussions

Nihilanthic

If the bushings are shot the rear will change toe more easily, and have trouble mantaining an alignment.

TECHNICALLY, DTSS is supposed to be rubber bushings that will be comliant in a tuned manner relative to lateral loads on the hub. However, when they wear out, they comply too easy (or if there not there its just free floating basically) and the toe changes a lot easier.

So, just eliminatnig it and making it a straight up semi trailing arm suspension thats more predictable is what lots of serious racers do. Semitrailingarms arent the best, but theyre not exactly BAD either - plus with limited wheel travel from having a car thast lowered and stiffly sprung and damped its not that big of a deal anyway.

Regardless, if you have plenty of power, and push it hard enough to actually approach the limit, you'll do better without DTSS.

bacek

very good information, i planned on eliminating them anyways when i replace all my bushings but just was never sure how they worked i just felt what they did when i cornered hard

jackhild59

iTrader: (7)

Uhh, sharper turn in is not usually described as push. Eliminating the DTSS should put the suspension permanantly on quick turn in mode. and it should be generally 'tail happy' .
No again, it will allow trailing throttle oversteer, which is inherently not controllable. This is how street drivers get in trouble in an emergency situation: Take an exit ramp at high speed, oh s**t! where did that concrete truck come from, back off the throttle, hit the brakes, watch the world spin around you.

No, DTSS should make initial turn in same as the solid bushings. After the transition trailing throttle or lift throttle oversteer should be controlled. How power induced oversteer will be affected, I don't know. I do know that if the driver is inducing power on oversteer and lifts the throttle (normal reaction), the designed suspension geometry is inherenly going to prevent further rotation of the rear of the car. When you 'break loose' it should ??? cause you don't specify what break loose means, push, throttle on oversteer, trailing throttle oversteer, or what. There is more to cornering dynamics than just breaking loose' or not. Using tihs general term to describe specific behavior is confusing to all.


Yes. True but muddled statement. React faster to have sluggish turn-in? Let me clarify this: Charactoristics of a worn DTSS bushing should be sluggish initial turn in due to faster compression of the overly compliant bushing assuming the bushing were completely shot anor transition would occor at a lower g-force if the bushing were just slighly shot.

This system is not nearly as mysterious as some would have you believe. It basically has 3 modes and they are simply a reflection of the amount of toe-in the rear suspension has at that time.

Mode 1) Under .4g's, No/low rear toe yielding sharp turn-in (tail happy)
Mode 2) Over .5g's Yes/more rear toe yielding inherent stabilty in most situations (not tail happy)
Mode 3) between .4g and .5g transtion between not toe and max toe allowed by the DTSS.

And FWIW, a worn DTSS system should have little effect on high speed cornering by itself. The toe-in built into the geometry would simply be fully in effect at lower cornering speeds (lower g-force). If you are experiencing unstable high speed cornering, it is probably a combination of lots of little (and big) things that are worn out and sloppy. These cars are generally old and lots of them have had the **** driven out of them. Age and wear takes it's toll on every bit of the suspension system.

And then, there is the driver...

If you really want to understand the handling dynamics of your car, you need to educate yourself on driving. I recommend the book
Going Faster!
Mastering the Art of Race Driving.

This book is worth a college education in driving fast. It is written by the head instructor of the Skip Barber Racing School. Danny Sullivan wrote the forward and Skip Barber wrote the introduction. They consider it THE reference manual for race driving education.

bacek

^that is what i thought... i was pretty sure the dtss was implemented in order to prevent lift off oversteer so people would not crash just like why most cars these days have traction control

Spirit Rx-7

iTrader: (15)

Interesting thread, I planned on getting me some DTSS eleminators, but not sure now. I just wan't my car to be more predictable, during highspeed corners my rear end feels loose, not sure if its about to oversteer or its just my DTSS.

jackhild59

iTrader: (7)

What about this thought. Are you talking about high-speed cornering or high g-force cornering? You could be at high speed in a sweeping corner and you just might be in that .4-.5 g zone. You might be experiencing the transition.

If you are cornering above that range of .4-.5g and you are experiencing instability, you have something else wrong. Something is worn or broken or your alignment is not up to snuff.

Tires, tire inflation, worn shocks, sagged springs, worn bushings including the DTSS can all cause problems with stability and tracking.

arghx

iTrader: (3)

I think my DTSS bushings are fucked. I had someone press them out the other day... picking the car up tonight with the new DTSS eliminators. When I go over a pothole the back end feels like it's going to the right, plus my turn in does feel kinda slow, but I've never driven a brand-new FC so I don't know what it's supposed to feel like. I've got new progressive springs and non adjustable shocks. Tires have lots of tread, fully inflated, and my alignment is perfect.

I'm not exactly a race car driver either, so that's probably not helping.

SexInDaRex

I installed them and I like them I of course wouldn't know thw difference. I just know that mine looked like they were fucked so I changed them.

arghx

iTrader: (3)

Finally got some good miles in on the car with the DTSS eliminators. Wow, I noticed a BIG difference over bumps. The back end used to really step out when I went on certain overpasses on the way to work. It is way more solid now... bump steer is vastly reduced.

bigdaddyp

out of line Question here, did the 86 GXL's come with the DTSS?

arghx

iTrader: (3)

all 2nd gens did I believe

88rxn/a

iTrader: (6)

back form the dead!!
instead of making a new thread..ill post here!
i have found metal sleeves and rubber eliminators...
now im sure the metal ones are better for eliminating but how well do the rubber ones hold up?
here is a link to the rubber ones im talking about..
http://cgi.ebay.com/ebaymotors/DTSS-...QQcmdZViewItem

eriksseven

iTrader: (6)

IIRC, Delrin is a metal of some type (I know this because skateboard bearings have "Delrin cores" or something). So yeah, not rubber.

Hot_Dog

Delrin is the brand name for an acetal resin engineering plastic invented and sold by DuPont. Often marketed and used as a metal substitute, Delrin is a lightweight, low-friction, and wear-resistant plastic capable of operating in temperatures in excess of 90 degrees celsius (approx 200 degrees Fahrenheit).

Hot_Dog
90 RX7 GXL

Hot_Dog

DTSS Bushings: Mazda p/n FB01-26-220 Bush, Rubber-RR lower Arm. They cost about $20 each.

Hot_Dog

The DTSS bushing consists of two concentric metal sleeves that are bonded together with rubber, which is positioned between these sleeves in four equally spaced segments. Simply put, they are like a typical rubber bushing, but with some of the rubber removed. Since these bushings affect the rear tow, the symptoms of bad bushing will resemble that of a wandering rear end while trying to maintain a straight course. For example, when the bushuings went bad on my 90 GXL, I would be driving down a straight interstate stretch and I'd have to have the steering wheel left-of-center to maintain a straight path. A few minutes later, I'd have to have the steering wheel right-of-center to maintain a straight path. This sequence would continue as I drove. Actually, it became very annoying especially on long drives. I installed the rear steer eliiminator bushing on my car about 5 years or 60K miles ago, and haven't regretted it yet. Removing these bushings was one of the best things I've ever done to my car.

Hot_Dog
90 RX7 GXL

rxspeed87

any quick reply on how do you actually chang ethe bushing?

can you do it with the part still on the car?

nitronatefc

iTrader: (2)

mazdatrix has a walk through on how to change them

http://www.mazdatrix.com/faq/rrsteer.htm

InMyWhiteTII

I cannot believe this thread is still current...

now

iTrader: (1)

has anyone installed these mmr ones?
I have a set here and they appear to be made to fit to loose in the hole?
the racing beat ones need to be pressed in but the mmr ones can be pushed in
with a finger and will fall out of shaken.
whats up with that? more ebay junk?
matt