STX setup sharing thread (2023)

[kraftyone]

For those running yoks what air pressures are you running? I was at 28psi front and rear and still could have let more out.

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[strat61caster]

Originally Posted by kraftyone

For those running yoks what air pressures are you running? I was at 28psi front and rear and still could have let more out.

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32/30 hot
I’ve run lower, it feels like the tire is doing more work but it never showed on the clock. I didn’t like lower then 28, it might work on low grip surfaces but I found it was really easy to overdrive and get that chatter that just feels bad. I think anywhere between 28-32 is Good enough. 30-32 just feels a touch more responsive then 28 without actually being slower.

[foshjowler]

Originally Posted by strat61caster

32/30 hot
I’ve run lower, it feels like the tire is doing more work but it never showed on the clock. I didn’t like lower then 28, it might work on low grip surfaces but I found it was really easy to overdrive and get that chatter that just feels bad. I think anywhere between 28-32 is Good enough. 30-32 just feels a touch more responsive then 28 without actually being slower.

I do similar, however keep the fronts at 30 and adjust the rears to determine how much rotation I want, typically 27 or 28. Tried running it down to 27/25 and they just feel much better with more pressure. Haven't done enough experimentation to know if they're faster/slower, but I suspect it's within the noise and I'll take having the feel.

[DocWalt]

Originally Posted by kraftyone

For those running yoks what air pressures are you running? I was at 28psi front and rear and still could have let more out.

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I've tested down to as low as 26/24 PSI (front/rear) but at more slalom/transition heavy sites, 28/26 PSI.


They do feel sharper with more pressure.

[Spuds]

Hey guys, currently running in STX with stock size street tires and I am quite ready to change that lol.

Just checking, 17x9 245/40 seems to be the size to have. Any comments on preferred offset? Does it really matter for autocross?

[strat61caster]

Tirerack sells +45, but they rub at full lock, so I use 5mm slip on spacers all around. +35 is the lowest you can go iirc and is common Subaru offset, anything around +40 is plug and play. Handling difference is minor, chasing tenths sort of thing.

[kraftyone]

I am running a +40 949 racing 6ul I do run a 5mm spacer up front but not sure its needed.

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[kraftyone]

Closer pick

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[jcaserta]

Originally Posted by strat61caster

Tirerack sells +45, but they rub at full lock, so I use 5mm slip on spacers all around. +35 is the lowest you can go iirc and is common Subaru offset, anything around +40 is plug and play. Handling difference is minor, chasing tenths sort of thing.

Not that it matters but I actually run +35 with a 3mm spacer in front so even lower offset is possible. I do have a decent amount of camber (had 5 degrees, now 4.8). It rubs less than 35 did.

[ka-t_240]

What are your thoughts on cat backs? Looking to change out my q300 and go to a stock mid pipe with the nameless ultra quiet track pipe.

Think doing this would leave some HP on the table? Looking at aftermarket pipes vs stock routing/sizes/etc.

[cmiovino]

Originally Posted by ka-t_240

Think doing this would leave some HP on the table? Looking at aftermarket pipes vs stock routing/sizes/etc.

More or less the catback isn't going to be sizable restriction. You might be leaving 2-3whp on the table... maybe... by keeping the stock catback. Most aftermarket catbacks are going to be so darn similar.

More or less, get something designed for your platform that suits the volume and noise you want. The header and tune are going to be 10x more beneficial in actually making power.

Weight is probably something to be more of a concern with for performance actually.

[DocWalt]

Catback is worth essentially no power

[jcaserta]

Originally Posted by ka-t_240

What are your thoughts on cat backs? Looking to change out my q300 and go to a stock mid pipe with the nameless ultra quiet track pipe.

Think doing this would leave some HP on the table? Looking at aftermarket pipes vs stock routing/sizes/etc.

I'm doing kinda the opposite, I have stock catback but jdl everything else including the jdl midpipe. It seems pretty good. Haven't gotten to a dyno yet though, just etuned, but on the butt dyno the car feels strong. It's honestly a bit too quiet so now trying to think about what to do.

My understanding is the catback is worth no power at all.

[jcaserta]

I should probably share my setup, it's been working very well so far. Just built it this past winter so we'll see how it goes once national events start up, NJ pro is in 2 weeks.

-2015 FR-S
-MCS 2 way remote with 6k/9k springs
-Karcepts sway bars front and rear. The normal size center sections.
-Verus rear LCA STX legal version
-OS Giken LSD 1.5 way
-17x9 +35 RPF1 with 245 A052
-Skunk2 intake with MAF insert removed
-JDL EL 4-2-1 header
-JDL overpipe
-JDL ultra quiet midpipe
-stock catback
-ECUtek tuned by xero limit
-Whiteline rear subframe bushings, rear diff bushings, and positive shift bushing
-Perrin motor mounts
-Master cylinder brace
-Ferodo DS2500 brake pads, stock calipers, castrol SRF fluid
-Forester oil cooler for track day bro time
-Camber 4.8F/2.6R
-Stock caster
-Toe 0F/0.33 degrees total rear toe in (that's slightly over 1/8" toe in, 0.14" or so)
-Ride height 12.95" F/ 13.2" R hub to fender metal

I'd like to try less rear toe maybe. Car feels just a bit too stable when I have the front bar turned up past 2. Everything's pretty close to ideal though.