STX Rules and Setup Questions

[bmacfrs]

Originally Posted by strat61caster

I like my Racer X rear end links, cheap too compared to everyone else. You have to unbolt to adjust length but they're compact as a result.

+1 on the corner balance woes, this car seems unresponsive to my ride height changes affecting corner weights, sway bars unhooked, ride heights are pretty close to nice based on fender measurements and measuring the pinch welds to the 'floor' (I use a laser level with the car on level platforms) jack three turns into the corners and next to nothing happens. Any tips would be appreciated, I think I need to take a apart the suspension and just try to rezero the heights and preload, good opportunity to check the top hats and clean it though.

I basically started over at one point too. Spent more time making sure the scales were as level with each other as possible. Then adjust coilovers to desired ride heights all around. Balance and adjust from there.
I think my mistake the first time was I started adjusting on the wrong corner. Then ended up compensating for that.



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[bmacfrs]

Originally Posted by H1C

Do you have some way of making sure that the suspension settles and unbinds on the scale pads?:



https://robrobinette.com/corner_weight.htm

I tried using folded over garbage bags between the tiles. Use the HD 30 gal kind. They slide on each other like butter. It worked well. Every time I set the car down I could see the tires push out to wherever they needed to go.


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[strat61caster]

Originally Posted by H1C

Do you have some way of making sure that the suspension settles and unbinds on the scale pads?:



https://robrobinette.com/corner_weight.htm

Yup, longacre side slip plates on two corners and a stack of linoleum tiles to help balancing add a little extra slip to the other corners. Tried oil between the tiles but that quickly turned to glue so they're dry now and the longacre pads move plenty on the left or right side of the car.

Making sure the pads (and consequently the car) is level is a big deal too, using a laser level and all four corners are <0.1" difference. After adjustment car is shaken by hand to help settle, handbrake off as that binds up the rear suspension. Our other car balances much more easily, the FRS is just hard to pin down for me, starting over might do the trick unfortunately, I might have messed something up on the initial setup of the coilovers.

Rob Robinettes site is pretty great for those that are looking into leaning more about diy setup, the link above is good reading on how one guy does it, but there are many ways to skin a cat. The suggestions are appreciated, some deep breaths and lots of patience

[H1C]

Originally Posted by strat61caster

Yup, longacre side slip plates on two corners and a stack of linoleum tiles to help balancing add a little extra slip to the other corners. Tried oil between the tiles but that quickly turned to glue so they're dry now and the longacre pads move plenty on the left or right side of the car.

Making sure the pads (and consequently the car) is level is a big deal too, using a laser level and all four corners are <0.1" difference. After adjustment car is shaken by hand to help settle, handbrake off as that binds up the rear suspension. Our other car balances much more easily, the FRS is just hard to pin down for me, starting over might do the trick unfortunately, I might have messed something up on the initial setup of the coilovers.

Rob Robinettes site is pretty great for those that are looking into leaning more about diy setup, the link above is good reading on how one guy does it, but there are many ways to skin a cat. The suggestions are appreciated, some deep breaths and lots of patience

I think I was lucky that my garage floor is uneven when I installed my coilovers, so I couldn't rely on fender heights to set the ride height. I decided to ignore the fender heights and just get the spring perch heights even left to right, measuring the threads on the shock bodies. I would up lowering the front first as low as it could go with 6" springs and no helpers, while keeping the springs captive at full droop. I measured the threads on the struts to check if it was even left to right.


Then I lowered the rear, trying to get a 0 rake as measured at the front and rear jacking points by the pinch welds to the floor. I again measured the threads on the shocks to get it even left to right, but then came back months later to lower the RR a couple of mm, after noticing (and having it confirmed by RCE Andrew) that the RR seemed to sit high with the L and R spring perches set to equal heights. I was surprised how balanced the LF/LR = RF/RR equation turned out to be using this guesstimated approach. I think Toyota and Subaru designed an inherently well balanced car.

[steverife]

My friends built wheel stands with adjustable feet. For slip plates, we use a bottom plate with a bunch of holes drilled in it, then fill the holes with ball bearings. Place a 2nd solid plate on top. And the stand contains the bearings when the inevitably get loose.

Much prefer it to messing with grease/garbage bags, etc.

[M0nk3y]

I simply created wood blocks as 2' roll off area behind the scales, where I'll just roll the car forward and back to unbind the suspension.

My perch heights aren't equal on any corner relative to another. Sure, it's a good starting point but not going to get you the corner weights that you want/need

[ein86]

So much easier than having to constantly jack the car up, cheap and easy to build too.

[bmacfrs]

I found this article helpful too.
https://dsportmag.com/the-tech/diali...balancing-act/

I really like their chart on what to adjust. attached.

[CoolHandMoss]

Wow racerx has some good fast shipping. I just ordered them the day after I asked about endlinks on here and they came today. With some gum.

[cueball89]

Does anyone know if front control arm front bushings are STX legal? I'm looking for a hair more caster if possible. If they aren't legal would the group N bushings for the 08-14 wrx fit? It seems like this bushing tears on other Subaru's fairly often.



https://www.suspension.com/superpro/spf3877k
https://www.whiteline.com.au/product...CA434&sq=22922

[CoolHandMoss]

As long as it has the same metal and rubber content. It can't have more metal and less rubber.

[strat61caster]

Originally Posted by cueball89

Does anyone know if front control arm front bushings are STX legal? I'm looking for a hair more caster if possible. If they aren't legal would the group N bushings for the 08-14 wrx fit? It seems like this bushing tears on other Subaru's fairly often.



https://www.suspension.com/superpro/spf3877k
https://www.whiteline.com.au/product...CA434&sq=22922

14.8.H.2
You'd have to give up the camber plates to use offset LCA bushings since they affect camber as well as caster imho and would be considered 'modifying the lower control arm'. The SPC looks like it runs afoul of 14.8.B by being a ball/spherical joint but the Whiteline looks like it could be kosher, but no way in hell it's worth giving up whatever camber plates+bolts you have.

For this car I'd recommend the Raceseng camber plates or Vorshlag has some that add caster as well unless of course you already have some caster from your plates.

[justint5387]

You can change the control arm bushings without giving up the camber plates.

Changing the bushing does not equal to changing the lower control arm.

[strat61caster]

Originally Posted by justint5387

You can change the control arm bushings without giving up the camber plates.

Changing the bushing does not equal to changing the lower control arm.

(╯°□°)╯︵ ┻━┻
Man fuck these rules, I'm still pissed about the multi-link one arm judgement, makes no sense the way it's written.

Don't get me wrong, I know you know your shit and half a degree of caster is nice but not game changing. I wouldn't mess with it but I can see the rules reading it as allowable per 14.8.B which is allowed with camber plates, but it's effectively modifying the LCA length which is what the 14.8.H.2 says you can only do if you don't have plates.

I'll shut up now