Deathbots

Now what's the scoop on these rear bushings that sort of 'steer' in a limited fashion when you turn hard?

Isn't it all of the 2nd gens that do that? And if I remember correctly, people replace something to make it stop doing that because it can get pretty scary.

If it's undesirable, why did mazda put it on there in the first place? What is the benefit?

rx302vert

the idea was to build in a safety zone for inexperienced drivers-the rear steer would "help" you-but it didnt work
Mazdatrix sells rear steer elimination bushings reasonably

Mykl

The DTTS adjusts rear toe in/out once you reach a certain amount of cornering G's.

Basically, it causes to the car understeer a bit more, but when it engages it feels like the rear end is stepping out a tad.

The only thing I wouldn't like about eliminating it is that I'd rather have a bit of understeer than a bit of oversteer. Once you get used to it and learn how to take advantage of it it's actually quite a handy little system.

But most people dislike it due to the vague feeling it creates when it goes into effect.

RETed

It's called Dynamic Tracking and Stabilizing Suspension (or something like that) - DTSS for short.&nbsp Under 0.5G of sideways force on the rear tires, would keep a slightly toe-out for quicker turning.&nbsp Over 0.5G, the rear tires toe-in for stability.

Yes, all FC's have them.&nbsp Racing Beat makes the DTSS eliminator toe bushings to eliminate this feature.&nbsp $40 gets you Delrin inserts with steel sleeves.&nbsp Yes, it's cheap, but the labor is not.&nbsp It's a royal pain in the *** job.&nbsp Mazdatrix has a write-up on their site.

It's for typical Joe Schmoe consumer driver.&nbsp It kept you from spinning the car out under heavy cornering conditions.&nbsp Those with any sense of driving skills usually don't like the feeling cause the toe change is very scary.&nbsp If you know how to use the DTSS, the car is a very stable platform - I said STABLE, not DESIRABLE.&nbsp It takes a LOT to push the car to oversteer spin.&nbsp The engineers when into a LOT of work to get that K-M rear hub to respond nicely.&nbsp Check out any copy of the 2nd generation RX-7 book by Jack Yamaguchi - there is an extensive write-up of the design process.



-Ted

InfiniIIIREX

This is passive rear steering, it only happens when you turn hard. This is opposed to active rear steering (like on my Galant VR-4) which will turn the rear tires at any turn above a certain speed (mine does it while going at 30 mph minimum) If you plan on doing alot of drag racing, a rear steer eliminator is a must because you want the rear wheels straight at all times.

Samps

I was under the impression that a car with a working DTSS could pull more G's? I thought that the system worked just fine; it just made the car FEEL a little strange.

Mykl

I don't think that's ever been tested, but perhaps.

Toe-in fights sideways motion. So toe-in on the rear tires at the limit will make it more difficult for the rear tires to kick out, causing the car to have a tendency to understeer.

You can really use that understeer at the limit to get on the gas coming out of turns a bit earlier. But that's how I use it. I also find it handy when I'm trying to transition the car quickly, it helps a lot with turning response.

Mykl

In general...

toe out = less stable at higher speeds, better turning response

toe in = more stable, reduced turning response

Too much of either and you'll eat tires pretty quickly. This is why the NSX has been known to go through tires in a hurry.

But, like I said, that's "in general". There are many other aspects to adjusting a suspension and each one of them affects the car's handling in it's own way.

Take my WRX for example. It has poor turn in response, especially compared to my FC. The car also doesn't like quick transitions very much. Initially to fix this I increased the rear tire pressure to 40 psi, with the front at 32 just to see what would happen. The handling is noticeably more neutral, and turn in is quicker. If I want to adjust this further I'll add a touch of toe out on the front tires in addition to a bit of negative camber.

Suspensions are complicated things, but you can really change the basic handling characteristics of any car by playing with them.

*ITEMS IN BOLD HAVE BEEN EDITED, THANKS FOR THE CATCH TED

Samps

What tire pressure do you run on the vert? I've tried 25 psi, 30 psi, and 35 psi. The best in my opinion is at 30 psi front and rear. I've never tried staggering the pressure front to back. If you have a good combo please share!

spankenstein

This thread explains a lot about how our FC feels. Wow. I've also got a Focus and it has passive rear steer. It's REALLY and on a FWD for lift throttle oversteer.

nathandarby67

Has anyone here actually swapped to a set of the toe-eliminator bushings? I'd like to hear some first hand experience of how the car felt before and after.

RETed

Uh, that's backwards.


-Ted

NZConvertible

That's got a lot more to do with the WRX being 4WD than suspension settings. WRX's are notorious understeers, especially power-on understeer. An aftermarket front LSD almost completely cures this but it's big $$$!

Deathbots

I have no intentions of replacing the DTSS stuff. If it's kind of scary 'feeling' but keeps me from spinning out (I'm probably more along the lines of Joe Average Driver) I'll take it.

Mykl

DOH

After reading that again uh, yeah, you're right.

I did a double take and changed it and I ended up changing it wrong. Thanks for pointing that out.

<--------- dyslexic

FEDREX

I think the DTSS delrin bushings should be the 1st suspension mod. They eliminate the yoyo-*** rear feel at limit and enable much better feedback to the driver.

I have no doubt my car achieves a higher cornering limit with these bushings. Anybody who favors them doesn't know jack about suspension tuning.

As far as the bushings reducing understeer - I didn't notice that effect at all. If you want more understeer you can do the following:
1. reduce front tire pressure - or- increase rear
2. install smaller diameter rear sway bar -or- remove rear sway bar.
3. if you have adjustable shocks you can firm the front and/or soften the rear.

Mykl

I run 35 psi all around in the convertible, mainly because with 32 I was seeing a lot of wear on the sidewalls and the outside portion of the tires. I was hoping this would help cure that a bit. The alignment is fine, wear is even on both sides, I just drive the car hard. I wanted to get it aligned with a bit of negative camber up front, but I haven't gotten around to it.

Yeah, if I ever get serious about the car I've already got a my differentials picked out. I was hoping that for the time being I could make due by adjusting and changing cheap stuff like roll bars and playing with the tire pressure. Surprisingly enough the tire pressure change really did help. The on throttle understeer doesn't bother too much, if I get the car pointed it helps me get on the throttle sooner and I can let the car push it's way out.

Understeer > oversteer

Is that so? For a stock FC you're better off using the rear steer. My car is stock and I like the way it handles, and I think the rear steer is quite handy. If I had a set of coil overs, adjustable sway bars, camber plates, and the ability to change alignment specs without having to pay $50 perhaps I'd get rid of it.

But then again, I guess I don't know jack **** about suspension tuning....

FEDREX

A thousand pardons...

If you think a stock FC corners better with the DTSS, that's your prerogative. Personally, I don't like that elastic feel when I'm trying to gauge steering input.

Having owned a 'stock '91 N/A, upgrading the suspension, and later adding DTSS cancellation bushings - the car cornered better with the bushings.
Ditto for my TII which also started stock.

I don't see how anyone can have a predictable slip angle at limit on an FC with a dancing rear suspension.

Apparently, you've found the secret....my hat is off to ya (but I'll keep my bushings)

RETed

I guess that includes me then!

That's pretty strong words.&nbsp A true driver should be able to adapt to the limitation of ANY suspension set-up.&nbsp In other words, they should be able to use an car's suspension efficienctly.

I never really got to push the STOCK FC suspension until I drove a bone-stock 1987 GXL for a daily driver when my FC was down.&nbsp Any of you Sac guys know about the I5/HWY50/HWY80 interchange in the middle if downtown Sac.&nbsp My daily drive required me to drive from South Sac up I5 and then over to HWY50 east to Rancho Cordova.&nbsp My return trips would require mid blasts returning the other way.&nbsp The HWY50 west to I5 south cut-off is a super smooth left turn that seems to go on for a loooong time.&nbsp The posted speed limit is 40mph (I think). I would gradually push the GXL with crappy non-matching tires through this turn a few MPH every day.&nbsp My record for going through that turn is 82MPH indicated.

My FC turbo has a fully built suspension - it scares me going into that turn that fast.&nbsp Go figure...



-Ted

Poindexter10thae

iTrader: (2)

I can drift just fine with my stock DTSS crap back there. But I am curious as to how it would handle with the eliminator bushings..........................................

tmak26b

Speaking of rear steering, I was coming down a turn. I was going in pretty hard. Right when I thought the corner was ending and ease up on the steering. The corner turned even sharper!!! I had to jerk the wheel real quick to turn. Next thing I know the back end was starting to slide, but at the same time I felt the rear steering kicking in. The rear steering does help when you are doing dumb things...

FEDREX

My apologies to the guys that favor the DTSS. My wording was arrogant - I'll try to be more empathetic in the future. Thanks.

Snrub

iTrader: (1)

I am too, I feel the car has too much understear.

Scott 89t2

umm. drifting is the reverse of handling

Mykl

No appology necessary. It's disagreements that create discussion, and I like discussion.

It all comes down to driving style and preferences. I too hated DTSS, but once I stopped trying to fight it and simply got used to it I changed my opinion of it.

The car would have a tendency to oversteer instead of understeer at the limit. The understeer at the limit is a good thing if you enjoy "performance" oriented drifting, not "show" drifting. With "show" drifts oversteer is a good thing.

But for "performance" drifting having understeer makes for higher corner exiting speeds since you can give it more throttle. Think about it, if the car is inclined to oversteer when you give it too much throttle the rear end is gonna kick out, screwing up your line and causing you to ease up on the throttle. But if more understeer is dialed in you can give it more throttle and let the car "push" itself out of turns.

Understeer = fast
Oversteer = show

It takes more practice and skill to drive a car with understeer fast, and there is such a thing as too much understeer. If you want to learn how to drift giving the car a lot of oversteer is a great way to start because the car will get sideways at lower speeds, and as you get comfortable with controlling an "out of control" car you can gradually dial in more understeer, thus increasing your speeds.



Okay, I found my old Autoweek issue that explains exactly how DTSS works. I typed it out rather quickly, so forgive any typing errors.