STX setup sharing thread (2021)

[Mike_ZN6]

Are rear upper control arms legal in STX? Assuming they have legal bushings.

[Breezio]

Originally Posted by PLX92

Hopefully get the car a bit more dialed this year:

2017 BRZ Base

17x9 Hypergrams
245/40r17 RE71R's (Will try Ao52's for 2021)

Any thoughts on moving to 255's? With a '17+ I would expect your top of second gear to be pretty low on the 245s.

I ran 255 A052s all last season and thought it worked great with my 17+

[Breezio]

Originally Posted by Mike_ZN6

Are rear upper control arms legal in STX? Assuming they have legal bushings.

I'd have to look it up to be 100%, but I believe the answer is, yes, if you don't do the lowers. You can do one or the other, I think.

Which basically means you should do the lower control arm and not the upper.

[PLX92]

Originally Posted by Breezio

Any thoughts on moving to 255's? With a '17+ I would expect your top of second gear to be pretty low on the 245s.

I ran 255 A052s all last season and thought it worked great with my 17+

I'm due for a set of tires so definitely a consideration, spent most of last season getting familiar with the limiter

[Mike_ZN6]

Originally Posted by Breezio

I'd have to look it up to be 100%, but I believe the answer is, yes, if you don't do the lowers. You can do one or the other, I think.

Which basically means you should do the lower control arm and not the upper.

I have rear lowers now but I am contemplating switching to rear uppers. My street wheels have a very aggressive offset and fitment would be better in the rear if I could tuck the top of the wheel more into the fender rather than push the bottom of the wheel out.

It appears Racer-X offers a urethane bushing kit for their rear upper control arms. That is the only option I am aware of for rear uppers that may be STX legal.

[M0nk3y]

Originally Posted by Mike_ZN6

I have rear lowers now but I am contemplating switching to rear uppers. My street wheels have a very aggressive offset and fitment would be better in the rear if I could tuck the top of the wheel more into the fender rather than push the bottom of the wheel out.

It appears Racer-X offers a urethane bushing kit for their rear upper control arms. That is the only option I am aware of for rear uppers that may be STX legal.

Fun fact. Basically every single lower arm besides a SPC LCA that has an bushing w/a cam bolt is deemed illegal per the letter of the law.

A RacerX LCAs (and every other design known out to man) control the LCA overall length, thus changing the actual suspension pickup point and thus it's an illegal mod.

No one actually protests it, because it's a serious slippery slope and the whole class would essentially be effected (except for those who have an SPC arm with a Diftech bushing pressed into place). Also most likely 99% a protest like that would be a result from the PC saying "Upheld, no advantage indicated". Protestee would get their fee back but no action would be taken.

Anyways, tl;dr - an upper arm is also illegal

[steverife]

Ran into similar years ago with the STS Hondas. Virtually everyone in the class ran the Ingalls slotted bolts on the upper front arms. Someone wrote in for a clarification and it was determined that they moved the pickup point and weren't compliant, bringing attention to the fact that probably 90% of the class was illegal less than a month from nationals. In that case, virtually everyone switched to an upper arm with an adjustable ball joint.

[M0nk3y]

Originally Posted by steverife

Ran into similar years ago with the STS Hondas. Virtually everyone in the class ran the Ingalls slotted bolts on the upper front arms. Someone wrote in for a clarification and it was determined that they moved the pickup point and weren't compliant, bringing attention to the fact that probably 90% of the class was illegal less than a month from nationals. In that case, virtually everyone switched to an upper arm with an adjustable ball joint.

Yup, exactly.

If you're the one that causes havoc on everyone else for switching something over you're going to have a bad time.

It's assumed as okay to run a LCA. Upper Arm? Someone may be salty about it. You do what you want to do.

[steverife]

Originally Posted by M0nk3y

Yup, exactly.

If you're the one that causes havoc on everyone else for switching something over you're going to have a bad time.

It's assumed as okay to run a LCA. Upper Arm? Someone may be salty about it. You do what you want to do.

Yeah. I was mostly mad at myself for not bothering to understand suspensions and the rules enough to recognize that. But I was also mad at the veteran folks that repeatedly recommended those parts and now expected me to spend a few hundred bucks to be compliant. Heck, Redshift still has a page up that tells you to run the Ingalls pieces.

[Racecomp Engineering]

One of the first things I'd like to check on the next gen BRZ is if they use an aluminum upper rear control arm (like some current Subarus). And then if it's the same dimensions as the current steel arms. Those arms + the whiteline poly upper cam bushings could be interesting.

- Andrew

[Autoxer62]

Given that I haven't done anything at all to the car in 2020, I'm thinking my 2021 setup will be suspension mods, I picked up some parts:

- Coilovers (still haven't picked, but the budget says something around $2k)
- Karcepts F/Mann R sway bars
- SPC RLC/Diftech bushings
- RPF1/255 Yoko A052

I'll probably do the Forester oil heater/cooler at some point too, seems like a good autocross setup since we could use quicker warmup as well as a little more cooling.

[smg1138]

Can anybody recommend some good camber plates? Looking for something with decent camber adjustment without too much NVH. Don't really think caster adjustment is going to be that necessary. The Verus plates look pretty nice for the price. Anybody using those?

[Racecomp Engineering]

Originally Posted by smg1138

Can anybody recommend some good camber plates? Looking for something with decent camber adjustment without too much NVH. Don't really think caster adjustment is going to be that necessary. The Verus plates look pretty nice for the price. Anybody using those?

The Vorshlag camber plates work great with our T2s. We like them a lot.

- Andrew

[strat61caster]

Originally Posted by M0nk3y

Fun fact. Basically every single lower arm besides a SPC LCA that has an bushing w/a cam bolt is deemed illegal per the letter of the law.

A RacerX LCAs (and every other design known out to man) control the LCA overall length, thus changing the actual suspension pickup point and thus it's an illegal mod.

No one actually protests it, because it's a serious slippery slope and the whole class would essentially be effected (except for those who have an SPC arm with a Diftech bushing pressed into place). Also most likely 99% a protest like that would be a result from the PC saying "Upheld, no advantage indicated". Protestee would get their fee back but no action would be taken.

Anyways, tl;dr - an upper arm is also illegal

Re read 14.8.H.6

Changes in suspension geometry are not allowed except as incidental to the effective arm length change.

Edit: the spc actually has a bigger effect on suspension geometry since it affects damper spring motion ratio to wheel motion ratio. RacerX keeps damper spring wheel ratios the same relative to each other.