suspension--tail swings out a bit at first stage of sharp cornering/turning

[JCH13]

Yes it is.



It surely does.

I had the exact same issue as the OP, when I went searching for help I found it under the slang "step out" and the proposed solution cured it for me.

It's good that you were able to find your answer (not that it's the same thing OP is seeing) but there's no good reason to ignore the proper terminology when discussing technical topics. It is very important to use the right terms to avoid being misunderstood.

 

[soccerballtux]

took a sharp turn today, felt much more planted / no oversteer like when RSB on sport.
In past, have had understeer where front tires broke loose first. That was scarier. Today, maybe pavement hot, tires stuck well, all slid just a bit through the turn. I'll have to keep pushing the limits...I really prefer the more planted feeling of the sport setting.

In other news, heard a pop with clutch depressed tonight, got it into gear once just barely and heard bit of chattering, 2nd time killed the engine, 3rd I could only push against [that normal something preventing the transmission from engaging when the clutch isn't depressed] and car inched forward. No fluid lost. Tow tomorrow...

So Uber Black ride home. The driver was black, but thought the Uber Black experience was about more than just that. Honestly if it were me I would have had vent-mounted drink holders to put the mini deer parks in, cycling them regularly, (water was about 90F), I would have just washed the car Thursday evening, and that would have included windexing the outsides and alcohol'ing inside the tinted windows. I would have fully functional GPS, and I wouldn't bother confirming the address in a Sudanese accent on the phone through bluetooth like a glorified cab driver when it was already put into the app. I'll try 2 more times, see how it goes, but if I were running Uber, it would be classier, regular inspections, provide standard GPS known to work, etc. However, I wouldn't have anything to talk about to the passenger, either. He had that going for him, but it's because I still come off [instructible] like a young student. When asked a question, I feel obligated to answer. Need to work on that, one step would be getting a BMW...

 

[OverVolt]

You should get life insurance for your loved ones since it seems you plan to fiddle with the suspension until you wreck. :awe:

Whats the tire width on that car? 225s? I'd also suggest AAA premium so that they can tow you to a nice repair shop after you lose control and bottom out on a curb.

 

[soccerballtux]

215/45

Exedy clutch replacement

How much life was left on this (currently 110k, my driving for 80k)? (aside from 4/6 torsion springs shot)

 

[jlee]

Looks like a bit of life left, but it's also starting to split. Doesn't look healthy.

The one I pulled out of my MR2 was worn almost to the rivets.

 

[yottabit]

took a sharp turn today, felt much more planted / no oversteer like when RSB on sport.
In past, have had understeer where front tires broke loose first. That was scarier. Today, maybe pavement hot, tires stuck well, all slid just a bit through the turn. I'll have to keep pushing the limits...I really prefer the more planted feeling of the sport setting.

I would suggest a couple things if you want to improve your car's handling further-

Biggest one is check tC forums because I'm not a tC expert but hopefully I can point you in the right direction

But possible improvements would be: stiffer (not lower) springs
Eibach Pro-Kits are typically a nice balance of handling & comfort. However anytime you're dropping a car with MacPherson strut you've got to raise spring rate correspondingly even just to get back to a baseline level of handling. Often times drop springs don't raise spring rate enough to significantly improve handling.

Alignment: You mention your "alignment is good". There might be more optimization for the alignment besides a factory alignment. It would have to be tC specific, but I've seen big gains on some other FWD cars by dialing in something like -2 deg Camber up front. Again dependent on suspension geometry, see what tC people are running.

Better tires: this is the biggest one of all! Stiffer sidewalls will give you more steering feel/confidence, more grip will increase the upper limits of the car

Sounds like you understand what the RSB is doing now. Just be careful and don't go too crazy with it! Higher speeds will exaggerate any of the effects you are dealing with. So a slight tail "stepping out" at 50 could be a complete spin at 80. I've driven cars set up for auto-cross where rotation can be desirable and they were a hoot to drive on the auto-x track but I would never want to take an onramp at high speed (or correspondingly a road coarse) with those suspension settings.

 

[soccerballtux]

^I was testing at 80
I'd need camber bolts but honestly I think the FSB is probably what I need to run the RSB on sport. which I want to do.

The TC forums were the ones that recommended the eibach low-kit and poni yellow shocks

 

[OverVolt]

Oh I know what'll increase your grip, wider tires rated for more grip.

A Scion tc is going to have lift at high speed. It ain't a ferrari. No matter how you tune your suspension when you are going 60+ and faster you are going to have less grip due to aerodynamic lift.

http://clubsciontc.com/forums/anything-goes-13/more-down-force-46256/

If you balance the steering for highspeed it'll probably handle like shit around 40-50mph and same thing if you balance the handling for 40-50mph it'll probably understeer at 80mph. Its the fact that its shaped like a Scion tc. I'd say balance the steering for 40-50mph and get wider tires with better compound and just deal with the understeer. Don't try and fight how the car naturally handles.

 

[_Rick_]

when you are going 60+ and faster you are going to have less grip due to aerodynamic lift.

"...gotta put a wing on it!"

Actually, maybe there are diffuser kits for the car, which should increase rear stability/grip at higher speeds.

Lower her, and put a GFX flat floor on that baby!

 

[JCH13]

took a sharp turn today, felt much more planted / no oversteer like when RSB on sport.
In past, have had understeer where front tires broke loose first. That was scarier. Today, maybe pavement hot, tires stuck well, all slid just a bit through the turn. I'll have to keep pushing the limits...I really prefer the more planted feeling of the sport setting.

Well? Which one is it? Planted with the RSB not on sport or planted with the RSB on sport?

^I was testing at 80
I'd need camber bolts but honestly I think the FSB is probably what I need to run the RSB on sport. which I want to do.

The TC forums were the ones that recommended the eibach low-kit and poni yellow shocks

Why are you testing at 80mph? Do you ever track this car? You don't need to "keep pushing it" if this car is a DD. Razor-edge balance and handling should not be your priority for a non-track car because it will require an inordinate amount of attention to keep it on the road and be much less forgiving in the unpredictable real world.

Why do you want to run the RSB on "sport" anyway?

It can be all too easy to fall into the trap of wanting track-car-like handling for a DD or non-track car. This is utterly pointless, for a variety of reasons.

What is your goal for these modifications you're making?

 

[soccerballtux]

Goal-- go-kart like driving

"Which is it?" -- I'm saying you were right about the RSB recommendation. there's no "step out" over steer as you called it like there was on sport. There is more chassis role though, which I don't like. Feels less go-kart and less predictable, even though it is technically (more predictable). I WANT the less roll that I get with sport RSB, but also want less oversteer that I get with comfort RSB setting

 

[JCH13]

Goal-- go-kart like driving

"Which is it?" -- I'm saying you were right about the RSB recommendation. there's no "step out" over steer as you called it like there was on sport. There is more chassis role though, which I don't like. Feels less go-kart and less predictable, even though it is technically (more predictable). I WANT the less roll that I get with sport RSB, but also want less oversteer that I get with comfort RSB setting

If you don't like chassis roll, anti-roll-bars (sway bars) are definitely the thing to get.

By "go-kart like" I assume you just want a more engaging and responsive driving experience, is that right? If so, lighter wheels and tires is a good next step. You don't need tons of grip, so don't go wide on the tires, just get the lightest wheel/tire combination that fits your brakes and are appropriately sized for the car. The reduced un-sprung and rotating mass will improve your suspension's response rate, improve steering feel, and give a small bump in acceleration and braking.

 

[uclabachelor]

Your rear sway bar is too stiff. Soften it or go back to OEM.

 

[brainhulk]

Ditch the sway bars.

stiff springs 10kg/mm front 11kg/mm rear on appropriately valved dampers. Camber @ -3 all around. Nitto nt01 tires. Don't listen to people telling you not to trail brake. Keep practicing it because everyone at the track trail brakes...everybody

Oh wait, you are only street driving...nvm

 

[soccerballtux]

Not changing springs shocks. Should I get a front/rear sway bar kit and sell the TRD rear?

JCH13, car came with alloys I'm happy with so limited upgrades there.

if less chassis roll and well balanced / no over/under steer I will be happy

 

[soccerballtux]

After clutch replacement, steering wheel alignment off 10 degrees. Already paid. Should I make clutch shop pay to fix alignment?

 

[JCH13]

Not changing springs shocks. Should I get a front/rear sway bar kit and sell the TRD one?

JCH13, car came with alloys I'm happy with so limited upgrades there.

You don't need a complete sway bar kit, just a front bar to balance out the rear bar. Preferably adjustable. Buying a new kit does have the advantage that both bars are designed to work together. Your call though.

If you are unwilling to upgrade your wheels and tires then... well... you'll have to settle for a lower level of performance unless you have some insanely light wheels already. RPF1s are less than $1k for your car (in silver anyway) and are 15lbs. But, it's your car and your call.

 

[soccerballtux]

You don't need a complete sway bar kit, just a front bar to balance out the rear bar. Preferably adjustable. Buying a new kit does have the advantage that both bars are designed to work together. Your call though.

If you are unwilling to upgrade your wheels and tires then... well... you'll have to settle for a lower level of performance unless you have some insanely light wheels already. RPF1s are less than $1k for your car (in silver anyway) and are 15lbs. But, it's your car and your call.

stocks are 19lbs. How could that be worth it?

 

[_Rick_]

stocks are 19lbs. How could that be worth it?

With a lighter tire, that makes for about 20% less unsprung mass, which will enable the springs to keep the tire in contact with the road for more of the time.

On the other hand, light tires might conflict with stiff sidewalls, which also sharpen up handling.
Nonetheless, unsprung weight is the best place to start, with the most pay-off.

Hell, I'm thinking about getting some Ultraleggeras for my Swift, now that there's a slight beloved patriot in the rim, after my roadtrip into hell-for-roads country. And that thing is still perfectly stock (but has predictable handling as far as I have experienced it, so for the moment I am loath to touch that. Brakes would be my first upgrade, and then there's that turbo kit.... :hmm

 

[JCH13]

stocks are 19lbs. How could that be worth it?

I can very easily feel a remarkable difference between 11.2lb Konig Heliums + 20lb Toyo RA1 tires and 13.2lb C1Ms + 21lb Hankook RS3s on my Miata. That's only 3lbs per corner on 15in wheels and it made a big difference. You'd be dropping more weight on larger diameter wheels, which would likely make a bigger difference on your car. If you get lighter and slightly narrower tires with slightly wider wheels you can make a big difference in the responsiveness of your car. A very slight stretch can help stabilize a tire's sidewall which leads to improvements in response and steering feel. This would be in addition to the benefits you'd see from reducing un-sprung and rotating mass.

 

[soccerballtux]

With a lighter tire, that makes for about 20% less unsprung mass, which will enable the springs to keep the tire in contact with the road for more of the time.

On the other hand, light tires might conflict with stiff sidewalls, which also sharpen up handling.
Nonetheless, unsprung weight is the best place to start, with the most pay-off.

Hell, I'm thinking about getting some Ultraleggeras for my Swift, now that there's a slight beloved patriot in the rim, after my roadtrip into hell-for-roads country. And that thing is still perfectly stock (but has predictable handling as far as I have experienced it, so for the moment I am loath to touch that. Brakes would be my first upgrade, and then there's that turbo kit.... :hmm

I can very easily feel a remarkable difference between 11.2lb Konig Heliums + 20lb Toyo RA1 tires and 13.2lb C1Ms + 21lb Hankook RS3s on my Miata. That's only 3lbs per corner on 15in wheels and it made a big difference. You'd be dropping more weight on larger diameter wheels, which would likely make a bigger difference on your car. If you get lighter and slightly narrower tires with slightly wider wheels you can make a big difference in the responsiveness of your car. A very slight stretch can help stabilize a tire's sidewall which leads to improvements in response and steering feel. This would be in addition to the benefits you'd see from reducing un-sprung and rotating mass.

I'll think about this...maybe I start with slightly wider tires on stock rims? 225s?

I got the sway bar kit. Front is (stiffer than stock):
*40%
*68%

My tRD rear that gives me oversteer at sport, (stiffer than stock)
*39% (street)
*64% (sport)

In speaking with Hotchkis they recommended,
*Light/Medium RSB + Soft FSB
*Medium/Hard RSB + Hard FSB

Is anything about this linear/what FSB setting would be best if I kept the RSB/match the percents? Their spec for the RSB is
*273%
*304%
*338%

I'll be putting the front on first but I'm concerned about much stiffer that rear will be.

 

[JCH13]

I'll think about this...maybe I start with slightly wider tires on stock rims? 225s?

That will not have the effect you want. You will be adding weight and softening the sidewall. It might help ultimate grip, but it will hurt feel and response, not what you want in a DD.

Here is a test that HRE wheels did: http://mbworld.org/forums/c63-amg-w...ects-wheel-tire-weights-wheel-horsepower.html

A drop of 12% in wheel/tire mass corresponded to an effective increase of ~2.5% in WHP because less power is used accelerating the wheels. It's a real thing.

I got the sway bar kit. Front is 40, 68% stiffer.
My tRD rear that gives me oversteer at sport is 39% (street), 64% (sport) stiffer. In speaking with Hotchkis they recommended Light/Medium RSB with "soft" setting on the front, and medium/hard rear with hard on the front. Is anything about this linear/what FSB setting would be best if I kept the RSB/match the percents? Their spec for the RSB is 273%, 304%, 338%. I'll be putting the front on first but I'm concerned about much stiffer that rear will be.

So many percents... so hard to understand...

I think what you're asking is: what balance should I apply to my car?

Basically, if you increase the front the same as the rear (in %) it will have the same balance as stock, but with less body roll. Making the front stiffer will cause steady-state understeer, making the rear stiffer will cause steady-state oversteer.

In your case, given your goals, I would install the front TRD bar at 'soft' and the rear TRD bar at 'stiff'. This will make it stiffer in roll than stock with a slight adjustment towards oversteer from the stock balance. I wouldn't get something 2.7x or more stiffer than stock, without chassis bracing and really good dampers you'll just be asking for trouble. Note - sway bars rely on your dampers for control, you wouldn't put on really stiff springs without stronger dampers, so don't put on really stiff sway bars without stronger dampers. This can cause a sensation of the suspension 'snapping' out of a corner, and corresponding lack of control. Also remember that your chassis is a spring as far as the suspension is concerned - it's stiffness matters. Too stiff of a sway bar will cause the chassis to flex more than it should.

 

[soccerballtux]

really like the front sway bar upgrade on stiff, but want more from it. Should I look at a front strut bar?

Still some step out ahem oversteer on the rear TRD at sport (+66%) setting. Next I will try the 266% (probably +166%) stiff RSB. What sort of trouble am I asking for here?

and I don't follow how sway bar->dampers snap. If both springs are compressing, both dampers are working in tandem, should be same as when separate

I am a little worried about the firewall spring effect with these stiffer settings

edit: ok I think this stiffer rear made a lot of difference, really enjoying
that and having your bushings freshly lubricated. Note to self.

 

[JCH13]

really like the front sway bar upgrade on stiff, but want more from it. Should I look at a front strut bar?

Still some step out ahem oversteer on the rear TRD at sport (+66%) setting. Next I will try the 266% (probably +166%) stiff RSB. What sort of trouble am I asking for here?

and I don't follow how sway bar->dampers snap. If both springs are compressing, both dampers are working in tandem, should be same as when separate

I am a little worried about the firewall spring effect with these stiffer settings

edit: ok I think this stiffer rear made a lot of difference, really enjoying
that and having your bushings freshly lubricated. Note to self.

No need to be a dick about it.

You could try a front strut bar or a stiffer front sway bar.

The trouble you are asking for is a further increase in oversteer. More RSB stiffness -> more oversteer as I (and others) have reiterated.

First of all, I did not say that the dampers snap, I'm not sure how you got that out of what I wrote. This has very little to do with the coil springs and everything to do with the sway bar. What a sway bar does, ostensibly, is to increase the spring rate (more properly - the wheel rate) of a car's suspension during roll (i.e. during a corner). While the dampers may do well to control the suspension's coil springs over bumps in the road they will struggle to control the added wheel rate of stiffer sway bars in roll. The dampers are not 'working in tandem' because both springs aren't compressing when the car rolls/corners - one side is compressing and the other side is drooping. The 'snapping' feeling some drivers report from using too-stiff sway bars is a result of the dampers being unable to control the sway bars' motion as a car exits a corner and the sway bars try to return to center.

What on earth is the "firewall spring effect?"

Now, before you get all "I gotta have no body roll!" seriously consider the ramifications of a further increase (I did not use the word "upgrade" on purpose) in your roll bars' stiffness: (1) you're reducing the independence of your independent suspensions, which will result in a loss of grip; (2) the added wheel rate of stiffer sway bars will overwhelm your dampers, which can only be adjusted in compression, resulting in a loss of grip and vehicle stability; (3) you'll increase the likelihood of jacking down your suspension, which results in instability and a loss of grip; (4) you might start approaching the limits of your end-links and chassis, where you'll start breaking components and/or the torsion stiffness of the chassis becomes your limiting factor (which has virtually no damping).

 

[jlee]

Or, if you want the feel of a precisely balanced RWD car...

...go buy one.