STX setup sharing thread (2020)

[M0nk3y]

Originally Posted by strat61caster

I did the math on a higher rev limiter a few months back (looking at the 58-62 mph range), not sure where it went, but even 3-4 mph faster over a few hundred feet was something like 0.01s which is totally negated if you're wide on a cone by a foot because you hamfisted your braking/downshift/turn-in trying to juggle everything at once.

Looking at the Bristol video above, if you nail your up/downshifts perfectly and adjust all your throttle/braking inputs appropriately, it might add up to a tenth, at best, but I'd absolutely take the safety of not worrying about the shifts given how hectic and transitiony those sections were. If I had a free half inch of wheel diameter to add on that course I'd make the swap though.

Great example of where this car straddles the line on gearing for national style courses. I've heard some people say autox is an exercise in damage control, a 98% run is usually faster than a 102% run.

As I've always said, a single run is all about minimizing your mistakes. You'll make them, but trying to not throw away the run is the difference.

Here is a good example where I would use 3rd gear. Even though I short shifted the speed mid/end of slalom is significantly better than holding it in 2nd

[Spade]

Jumping in this thread as I just bought what seems to be a slutty FRS that's been with a few STX autocrossers

Its on Ohlin single adjustable with 400lb springs all around and typical boltons, 17X9 RPF1s with 245 Rivals.

Edit, question since the last RWD Autocross car I've had is a NB Miata. Why is it that we don't want the rear brakes doing much on the FRS/BRZ?

From previous owners, it has AP Racing BBK in front with good Ferodo pads but only the Hawk HPS mickey mouse pads in rear.

On a NA/NB Miata we purposely put more aggressive pads in rear. It has HP+ rear and Stop tech sport front on sport package brakes.

[bmacfrs]

Originally Posted by Spade

Jumping in this thread as I just bought what seems to be a slutty FRS that's been with a few STX autocrossers

Its on Ohlin single adjustable with 400lb springs all around and typical boltons, 17X9 RPF1s with 245 Rivals.

So you're saying she a bit loose?

Sorry couldn't help it. Congrats. I'm sure you'll have a blast.
What's it got for sway bars and brakes?


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[Spade]

Originally Posted by bmacfrs

So you're saying she a bit loose?

Sorry couldn't help it. Congrats. I'm sure you'll have a blast.
What's it got for sway bars and brakes?


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I think it's a slightly bigger one in front and a disconnected rear.

I have another bigger sway bar in box. What's the going ideal set up?

Brakes are AP Racing BBK front with good Ferodo pads. Hawk HPS (shoe leather) rear. I was told the rear shouldn't be doing much in this car which conflicts with my usual knowledge

[steverife]

The Miata rear brake thing is to try to mitigate front lock up when driving a non-ABS car aggressively.

Brake kit for just the front and rear sway bar disconnected sounds a little, uh, atypical for an STX setup.

[strat61caster]

Originally Posted by Spade

Edit, question since the last RWD Autocross car I've had is a NB Miata. Why is it that we don't want the rear brakes doing much on the FRS/BRZ?

From previous owners, it has AP Racing BBK in front with good Ferodo pads but only the Hawk HPS mickey mouse pads in rear.

On a NA/NB Miata we purposely put more aggressive pads in rear. It has HP+ rear and Stop tech sport front on sport package brakes.

The AP Racing brake kit doesn't change the bias, it's there to increase thermal capacity, reduce brake cost and drop ~20# off the front end. Not much weight to lose off the rear nor any change in bias is necessary so not having a rear brake kit is pretty common imho.

Staggered pads is unusual though, the factory brake system likes to add rear brake pressure to reduce rotation under braking, I could see that being an issue in Street class that a prior owner liked the staggered pads instead of the pedal dance and just didn't revisit after building STX. I've found when the suspension is happy I get all the rotation I need under braking with same pad compound front and rear and that seems to be the common consensus.
https://www.ft86club.com/forums/showthread.php?t=25494

Unhooked rear bar isn't super common, but it's pretty weaksauce to begin with. I'd like to try disconnecting it as a rain setup and softening the front. The car likes a stiffer than factory front bar, I've heard 20mm to 25mm, 22mm solid adjustable seems most common.

The car is sensitive to alignment, some choices with toe and camber can drive the owner to compensate in other areas such as spring rates, damping, and sway bars, it might have been a factor in the brake choice too.

[Autoxer62]

I'm looking at rear lower control arms and wanted to make sure I understood the rule correctly - as long as I have a solid non-metallic bushing (that is, not a spherical of any kind) all the various aftermarket arms are legal, yes?

If that's true, then setting aside cost what's your preferred choice? I'd like something that's light and easy to adjust.

[M0nk3y]

Originally Posted by Spade

Jumping in this thread as I just bought what seems to be a slutty FRS that's been with a few STX autocrossers

Its on Ohlin single adjustable with 400lb springs all around and typical boltons, 17X9 RPF1s with 245 Rivals.

Edit, question since the last RWD Autocross car I've had is a NB Miata. Why is it that we don't want the rear brakes doing much on the FRS/BRZ?

From previous owners, it has AP Racing BBK in front with good Ferodo pads but only the Hawk HPS mickey mouse pads in rear.

On a NA/NB Miata we purposely put more aggressive pads in rear. It has HP+ rear and Stop tech sport front on sport package brakes.

#400 square on a STX FRS setup is a pretty common spring package. I had this on my car for the first year and found it to be a tad bit transitionally loose so I dropped to #350 in the rear and got much more comforting at higher speeds. So something to just keep in the back of your head if you seem to start experiencing those issues. Personally, just hearing the rear bar disconnected makes me think they were already battling these issues in earlier life.

Perhaps PO's thinking on the rear pads were trying to prevent the rear brakes from screwing around with the LSD, as they do clamp in some instances during yaw even with stability control completely off. Honestly, don't overthink it just match the rear pads and drive the car. I've run AP Racing BBK with 2500s all around for the past 2 years. It works. The rear pads are so small to begin with the last thing I'd want to do is shift bias more up front with an HPS pad.

Originally Posted by Autoxer62

I'm looking at rear lower control arms and wanted to make sure I understood the rule correctly - as long as I have a solid non-metallic bushing (that is, not a spherical of any kind) all the various aftermarket arms are legal, yes?

If that's true, then setting aside cost what's your preferred choice? I'd like something that's light and easy to adjust.

Verus Engineering IIRC is one of the only "legal" solutions that is available for the car still with an STX compliant bushing. I personally have RacerX, but they stopped production it seems.

[Mike_ZN6]

Originally Posted by Autoxer62

I'm looking at rear lower control arms and wanted to make sure I understood the rule correctly - as long as I have a solid non-metallic bushing (that is, not a spherical of any kind) all the various aftermarket arms are legal, yes?

If that's true, then setting aside cost what's your preferred choice? I'd like something that's light and easy to adjust.

Not all aftermarket arms. I know the SPC rear lower control arms are illegal for STX. They do not have a spherical bushing, but they have an OEM style bushing that is metal instead of rubber. People have to replace the SPC bushings with urethane ones to be STX legal.

[Autoxer62]

I guess what I was thinking was to get a set of used arms with a rod end and then swap the rod end for something like this:

https://www.summitracing.com/parts/cee-6152

So long as I do that, I think the arms themselves are legal. Am I missing anything?

[Roadphantom]

Originally Posted by M0nk3y

#400 square on a STX FRS setup is a pretty common spring package. I had this on my car for the first year and found it to be a tad bit transitionally loose so I dropped to #350 in the rear and got much more comforting at higher speeds. So something to just keep in the back of your head if you seem to start experiencing those issues. Personally, just hearing the rear bar disconnected makes me think they were already battling these issues in earlier life.



Perhaps PO's thinking on the rear pads were trying to prevent the rear brakes from screwing around with the LSD, as they do clamp in some instances during yaw even with stability control completely off. Honestly, don't overthink it just match the rear pads and drive the car. I've run AP Racing BBK with 2500s all around for the past 2 years. It works. The rear pads are so small to begin with the last thing I'd want to do is shift bias more up front with an HPS pad.







Verus Engineering IIRC is one of the only "legal" solutions that is available for the car still with an STX compliant bushing. I personally have RacerX, but they stopped production it seems.

Curious to hear what sway bars and setting you were running on 400/400 when it was a tad loose in transitions? Did you have to readjust your sway bars going down to a 350 rear spring?

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[M0nk3y]

Originally Posted by Roadphantom

Curious to hear what sway bars and setting you were running on 400/400 when it was a tad loose in transitions? Did you have to readjust your sway bars going down to a 350 rear spring?

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At the time was Perrin 22mm bar on soft. Mann Engineering Rear bar.

When I went to 350# rear I was still on 22mm soft, Mann Bar.

Now I changed a bunch of things and went with a Karcepts bar and that gets changed around about every event

[racingfool]

Originally Posted by Autoxer62

Am I missing anything?

This perhaps?

In a replacement bushing, the amount of metal relative to
the amount of non-metallic material may not be increased.

[strat61caster]

Originally Posted by Autoxer62

I guess what I was thinking was to get a set of used arms with a rod end and then swap the rod end for something like this:

https://www.summitracing.com/parts/cee-6152

So long as I do that, I think the arms themselves are legal. Am I missing anything?

Assuming you can find a rod end that matches the thread, get the hole sized for the factory bolt, and meet the percentage metal/non-metal requirement then yes, you could swap that and get it working. I looked into it a bit and got a headache and just stopped, not super easy imho.

I like the threaded adjustment too, but even buying used parts I think it'll be hard to beat the value of the Whiteline/SPC LCA with a legal bushing pressed into it. Once you figure out what toe/camber you like back there for stability and tire wear odds are you won't want to touch it.

https://www.ft86speedfactory.com/whi...E#.XrxUc2hKhPY

Be aware on the arms that provide multiple adjustment holes or static lowering, not ST* legal, but I think they have OE positions so as long as you bolt the damper/swaybar into the right hole it should be fine.