..Starting the quest for total neutrality.
 

So, I've recently purchased my beautiful "Raven". A 2013 Scion FRS in the Pearlescent Black. Bone stock, very clean. I've had it for nearly a month now. I've learned it's limitations pretty well on the Eagle RS-A's it has and the stock suspension. I'm putting a parts list together for what I want to do to the car.

So har I have Racecomp Engineering Yellow Shocks. I'm looking at sway bars and endlinks/chassis bracing now. What set of bars combined together with what adjustable end links with 250lb/in front and rear spring rates will give me neutrality? or close to 50/50?

Is there some FRS/BRZ suspension calculator like FCM has a Miata suspension calculator? If so, please link me! I like being able to crunch the numbers and find what is going to be best.

neutral is relative. too many variables.
1. tires.
2. driving style.
3. conditions.
4. speed.
5. sum of parts.

I am suggesting a brand that does a front and rear sway kit. Preferably adjustable. This way you are getting close to matched sway bar stiffness front and rear plus you can dial them in a little yourself.
Both Eibach and Whiteline do an adjustable kit but there are probably other kits out there.

I would go with the Hotchkis swaybar set. the front have 2 settings and rear have 4 settings. it's also developed for the stock endlinks. I'm also getting RCE yellows, but in the opposite order as you. swaybars first then springs for me. also look into a rear LCA if you don't want too much negative camber. my plan is to get the hotchkis set, go to the track, then get the RCE's and racerX LCA before going to the track again. the $$ adds up over time when modding your car even though it doesn't seem like it lol

This.
Don't make the mistake of keeping a record of what you have spent on your car. It will end in tears.

The term "total neutrality" can be a bit ambiguous. Do you mean completely neutral (i.e., 4 wheel drift) in a corner with just maintenance throttle? At what speed/radius?

I ask because I suspect a car that's setup like that will feel very loose to most. Any trail-braking will bring the rear end around, and you'll have to be careful with the throttle. I think it'll also be slower on a lot of courses because of inability to get power down on exit, unless you're absolutely comfortable managing oversteer.

A tiny bit of front-end push is good for stability -- especially on higher speed corners -- and you can use trail-braking to fight the slight understeer entering corners. Just my 2c as someone who also prefers "neutral-ish" setups.

We do also make an RCE swaybar set (hollow bars front and rear). :)

A lot of it will come down to alignment and making the most of the tires as you can. You may want to consider camber bolts or plates if you don't have them yet. A good amount of "from the seat" balance comes from alignment.

- Andrew

GOSPEL RIGHT HERE.

First off what is the car doing that you are trying to correct? What isn't neutral? You cannot hope to get a proper answer from "make my car neutral" because anything anyone prescribes may work for them but not for you.

My experience is useless because I don't know what RCE does to the balance, but what they say above is absolutely true, you can get a totally neutral car from alignment tweaks alone if that's your goal, I'm really happy with stock suspension + front camber plates and 200TW competitive tires. On stock springs/dampers the car really likes having >-2.5 degrees camber up front.

Edit: Autocross? Track? High speed track or low speed track? Canyons? Drift?

I drive like a bat out of hell in the mountains. I have noticed that the vehicle is prone to mainly oversteer (although yes, that was its intent from Toyota) and I'd like to be able to dial out that. There is little understeer I've seen with the vehicle, and what understeer I have seen was EASILY correctable. I want a vehicle in short, that if I push it to its limits, it won't favour either under or oversteer; 4-wheel drifting, essentially. I also wanted a slightly lower vehicle (~20mm front and rear, which is why the RCE Yellows are a choice) with use of stock struts to maintain reliability. I know lowering a vehicle with stock sway bars and endlinks normally upsets the preload of the sway bar, negatively impacting handling characteristics. I'm aiming for a 200 UTQG tire. Something in the area of RS3 v2's, Rival S's (I had the Rival in a 225/45/15 on my NB1 Miata) and the RE71R categories as far as performance. 17x9 Ambit RE02's are my rim choice that I want. Looking for something aggressive enough with OK reliability. Driver modding is the cheapest and easiest, and so far I have feeling that I've fared well with driving this car.



Is there a specific precision alignment that is advertised on any of the FRS forums that improve handling characteristics with stock tires/rims/suspension?

I know in my Miatas I preferred 5+* Caster for initial turn in with zero toe and ~1.5* camber.

Even the FR-S has a fair bit of understeer built in, although nobody will argue that oversteer can't be induced at will on tight twisties at lower speeds. My point is that the oversteer you're describing is caused by your driving style - it's really that simple.

The funny part of this is, if you wanted more neutral handling you should've gotten a BRZ to start.

-alex

It feels silly to echo the previous comments, but... alignment?

Regardless of where you define "neutral" it's driver input that keeps it there. ANY reasonable setup can be made to understeer or oversteer simply by changing driver input. Understeer is "safer" in general, but a car that's slightly tuned to oversteer can be held at its limits quite easily once you know them, but still requires tuning to the comfort level and particular habits of each driver.

Tuning out an undesired behavior in a given scenario may be easier - corner entry or exit, on throttle or off? ... but may still be driver input. If I had tuned for what felt "neutral" this spring, I'd be upset about balance today... only thing that has changed is the driver.

C

Are you planning on using front camber plates/bolts or rear LCAs?

- Andrew

Specific alignment specs - no

But the overwhelming consensus, as shown in this thread, is that everyone is saying more negative camber upfront does wonders. How much camber, toe, caster is up to your application, driving style, etc.

Fuel weight makes a difference, a gallon a gas is roughly 6 pounds of weight. Now if you use one gallon on a track or other event weight shift differentials will impact the car. So if you test parts with a 1/2 tank and you fill to 1/2 tank for an event you'll get the setup you tested for. Just an idea

Adding to this; I'm running -2.5 degs camber in the front, -1.5 degs camber in the rear, an extra half degree of camber, and zero toe everywhere. The zero toe would normally be considered very aggressive, expecially for the street, but it works amazingly well. There's no pulling or twitchiness on uneven pavement at any speed I've had the car at. I'd have no trouble suggesting these alignment settings to anyone else.

I don't know, but I think stock to stock FRS is more neutral compare to BRZ. BRZ is more stable & turn in isn't as sharp in a tight spot.

@Hatchi

It's unusual to complain of oversteer, general consensus is that the FR-S understeers at the limit with a few outliers disagreeing. Personally just about every instance of oversteer has been due to my inputs.

All my tweaks have been to reduce understeer, the front seems to like more than -2.5 degrees of camber, I was happy at about -3 degrees at my last track day, I've been running ~-2.7 at AutoX and will be upping that to -3 this weekend. Don't have rear LCA's to dial that in yet.

Zero toe in front I'm happy with eventually I'll try some toe-out for autox purposes. I ran zero toe in the rear for a few weeks and the car felt like it wandered on the freeway so I've got some toe-in back there, maybe not the fastest but I spend more time on public roads than private ones.

Best of luck

Most of the alignment settings people have been recommending (zero toe, -2.5 to -3.0 degrees front camber) are aimed at decreasing stock understeer.

I gather from his posts that OP actually wants the opposite:

Stock alignment specs are already fairly conservative (slight toe-in, 0 front camber, -1.0 to -1.5 rear camber). I don't think you can feasibly do a whole lot there.

OP - I think the first step is get rid of the Eagle RS-A tires and replace them with proper performance summer tires (MPSS, RE71R, Z2SS, etc.) I have a feeling that will give you the rear traction you're looking for on exit. If that's not enough, Strano parts makes an affordable front sway bar that will shift the balance of the car more towards understeer (i.e., reduce oversteer).

I think why most people who thing the stock frs suspension oversteers is simply because of how quickly (or easily) it can transition from under to over upon throttle input mid corner. Otherwise, even when you trailbrake into a turn on a stock FRS, the front end will plow. That is, unless you have some crazy toe out dialed in.

If you're thinking the FRS oversteers, then perhaps you can try the swift BRZ lowering springs (3.8k/4.5k). Having done this mod myself along with additional front camber via camber bolts this really help make the car handle much more predicable versus the completely stock suspension. less understeering corner entry and easier to control how the rear end rotates under throttle. The RCE springs (4.5k/4.5k?) are probably also a good choice.

Pedal dance is your friend :)

I recently learned about Pedal Dance... It's drastically improved the capabilities of the vehicle. Coming from a Miata with ZERO driver aids, it reminds me a whole lot of my Miata. All of my Miatas were prone to oversteer, no matter what I did to the car. So, having something that is 100% mechanical now makes me feel a little more comfy. These RS-A's have 9/32"..... No chance I'm gonna get rid of them unless i can find a HELL of a deal on some stickier 215's (being as for now I'm constrained to stock wheels)

Is it safe to run this alignment on the car with stock tires and rims:

FRONT:
Camber -1.6*
Caster: 5.75*
Toe: 0*

REAR:
Camber: 1.2*
Toe: 0*

NO, I do not plan to use LCA's or adjustable anything, at the moment. I'm going to squeeze every ounce out of this cars stock capabilities and then see what I want to do. This car is a budget constricted one, that needs to maintain reliability. So modding the crap out of it right off the gate... NOPE.

IMO that is the RIGHT way to approach these cars. They drive beautifully stock with just a good alignment (max camber front; get the OEM crash bolts; they are super cheap and if you are going to get an alignment, these are a cake to toss in). They tend to easily understeer and oversteer depending on what you tell them to do which just makes you a better driver if you can learn to drive the car "neutrally".

Regarding your alignment specs, I'm assuming you meant negative 1.2 rear camber so the only things I'd suggest is to get more front camber with the OEM crash bolts and put in a touch of toe in for the rear. But, again, it is driver preference.

When I had RCE yellows, I put ST front and rear sway bars as they are the softest set available above stock, and had 215 Pilot super sports. Combined with equal-ish camber on all 4 wheels from spc front crash bolts and rear control arms, it was a very neutral setup with hints of understeer/oversteer behavior caused by manipulating the throttle.

I totally agree with the OP. I've always felt my BRZ is very "twitchy" with the TC and VSC off. I haven't used the pedal dance before but it seems to me the car rotates very easily with even a small amount of throttle input in a corner. I'm not talking about tracking or autocross, just street driving.

I don't need or want the car to be set up for the track because I don't track the car. I'm on the street 99.99% of the time.

12mm camber bolts work to adjust (+ or - .5 deg) camber in the rear, if you need it. Check rockauto.com for camber bolts for a chevy cobalt.

- Now, what is the most appreciative bias when it comes to camber on this car?

Yes, the car feels very mechanical and snappy like an older sports car did when it came off the lot, brand new. Easier to manipulate...

I've found myself inducing oversteer on purpose to exit corners quicker. It's very nifty but also a drawback when you're hitting uphill hair-pins and you lock up.

Alignment is absolutely the most fun thing to play with on this car in order to fine tune the balance. :)

I'm running a nearly identical setup to @Calum ; -2.5 up front, -1.5 rear and 0 toe all around - and I'm similarly confident in recommending these settings as a baseline for an aggressively driven street car. I find the distribution of traction to be very neutral overall with plenty of front end grip on tap plus an ability to initiate rotation in the rear if you're super aggressive with your throttle lifts and/or steering inputs. Although it's a fairly aggressive setup it's not too rough in terms of tire wear, which is also nice.

Working from the above settings I find that simple toe adjustments are enough to be able to tweak the balance further, depending on my mood and preference:

- an extra half a degree of toe in (total) out back locks the rear end down a bit more.
- an extra half a degree (total) of toe out up front increases initial turn in response.

I'd suggest not looking into swaybars until you've completely exhausted all of your alignment options. That's not to say that swaybars are bad per say, just that the alignmen5 changes are really easy to notice and by far better bang for your buck.

On the topic of swaybars I'd be careful what you choose. I'm running the Hotchkis bars, which are very stiff compared to stock (over 200% stiffer at the softest settings). They're good match for full R compound rubber and even more aggressive alignment settings on a track but not so good on the street, with street tires and a less aggressive alignment. They do keep the car extremely flat but I get a lot of crosstalk on bumpy surfaces and the breakaway characteristics are very abrupt. I'll be swapping back to a much milder swaybar combo soon.

I'd actually recommend swaybars as an absolute last step in the 'mod chain' but that's just me. If you're super keen offense dialing in your car I'd speak to a pro and get them to recommend something tailored to the other parts already on your car and your own specific use cases.

A handy reference comparing different swaybars is here:
http://www.ft86club.com/forums/showp...25&postcount=1

This reminds me of a youtube channel I was watching the other night, and a particular video. I think you might enjoy this, if nothing else it's food for thought. [ame="https://www.youtube.com/watch?v=WhWZ57baTOw"]FCM Suspension Truth v2.6 - The Hidden Cost of Sway Bars - YouTube[/ame]

Disclaimer: I don't know enough to be critical of what he's saying, to me it was a compelling argument. That video also confirms some hypotheses I've held onto about sway bars, so there could be some confirmation bias.



Personally, I'm modding my car in an effort to mask my poor driving abilities. My goal is to make it so I can hold the car as close to the edge as possible, with some nod to decreasing the understeer that I found in steady state cornering. So, all of the mods I've done have been in an effort to increase; feedback, stability in mid corner bumps, and predictability when cornering forces overcome traction.

In that vein, I've been holding to the idea that I'll be staying with the stock sway bars. I've had a car that was grossly over barred, it was fun to a point, but the snap over steer was dangerous and kept me from using the car as much as I could. I might go to a wrx rear bar to change balance slightly, but I'm very satisfied with the balance as it sits.

Another thing to consider when upgrading sway bars is corner exit. I think increasing sway bar stiffness will reduce grip and thus the cars ability to accelerate out of a corner.

I'm sure there's compromises and balances to be found with all of this, things like upgrading the differential to combat the loss of grip from the sway bars.:iono:

@Calum if you're still understeering at -2.5 degrees camber up front try adding more, my car was the happiest it's ever been at the last autocross (so no corners above 40mph even) running about -3 degrees, I'm on stock everything else except tires (Z2SS OEM size).

Going to try -3.25 in a few weeks, it's not streetable, I adjust camber via my plates after arriving at the event and before leaving, I could feel the inside edge getting real hot after only a ~4 mile drive one day.

Andy, is that you trying to sell me a set of camber plates, again? /s

Honestly I'm really happy with the amount of understeer with this setup. It's very controllable and yet enough to keep to me out if trouble. But that is some good food for thought, I'm presently maxed out on camber though.

Haha, I had nothing to do with that I swear.

The FCM video series is good information. Keep in mind that he's talking about Miatas and that every car is different. I do think with Subarus in general a lot of people go too big on swaybars simply because it's a cheap and easy way to keep your car flat and huge bars are easily available.

There are many ways to get your car to rotate. What's important for most of us is finding the balance that maximizes the grip that you can confidently use. :)

- Andy

@Calum

I was looking into sways for AutoX, and in both the CS and STX thread, many are doing just a front sway and/or very very mild rears

I found going from -3.2 to -2.5 very noticable in terms of understeer on the track. I changed it for the winter because I'll be driving 2000 miles round trip from the NW to Sonoma and Laguna. Otherwise, for around town and 4 hrs round trip to the Ridge Motorsports park once or twice a month, I found -3.2 to be fine for inside wear as the tires wore out from track use before the inside wear was an issue. This is on Z2SS, NT01s, AD08Rs and RE11s.

So I might not be completely full of shit...:happyanim:

I don't have the luxury of a second set of wheels at the moment, my Z2SS have 12k miles on them at the moment and I believe should be good for another 3k-8k miles depending on how hard I run them, just rotated front to back and my fronts have noticeable inner and outer shoulder wear compared to the rears, I've driven them hard and easy at both a lot of camber and not enough camber.

:bellyroll:

I'm confident adjusting my plates on the fly that my toe change is minimal (totally unnoticeable from the butt dyno), hopefully sometime this winter I'll go through and generate some plots on the interdependance once I get some alignment tools so I've got data to back me up.

I was driving to work at ~2.5 degrees, ~4 miles and the inside edges were so hot they were uncomfortable to touch and the outside edges were ice cold, I went back down to my max positive that night.

Agreed, a couple thousand miles on the street is nothing compared to a hard track day, but at this point my tires are seeing at least a thousand miles between events, changing the camber is the least time intensive part of my setup (changing tire pressures takes longer, let alone brake pads) so I feel comfortable reccommending it.

I've never seen 2.5 degs wear unevenly. Are you sure you don't have a toe issue? That seems more likely.

Entirely possible, my only counter argument is my toe has been adjusted professionally 3 times now and the steering feel has never changed significantly. Going from -1.1 degree to -2.7 degrees camber and ~4 months between being on the rack including 4x autocrosses was still within factory spec, I'd have to go look at the sheet for exact numbers.

I was just wondering about toe too. I have -3.3 and zero toe, no heating like that on road trips for me. Also even enough wear... Very even wear on the race setup but that's just to/from events plus a few minutes of munching cones.

Also stock swaybars in STX, but hey...