STX setup sharing thread (2021)

[RT-BRZ]

Originally Posted by nathand

Is the 22mm FSB the undisputed way to go vs something smaller with the same spring rates front and rear and stock diff and stock rear bar?

I'm running the Hotchkis matched set (25mm front, 19mm rear) and it has been great for me.

[Locust]

Originally Posted by Breezio

Perhaps on the 13-16 cars. Top of second gear would be way too low with 245's on my 17+.

What? How is the width affecting your speed?

[RT-BRZ]

Originally Posted by Locust

What? How is the width affecting your speed?

The slightly wider tire increases the total diameter of the tire when using the same sidewall ratio. The larger diameter tire has the effect of reducing the effective ratio of the rear gear ratio in use. So, the 4.10:1 gear may end up being 4.05:1 effectively. (I haven't done the exact math but the principle is there).

A lower numeric rear gear ratio means less effective acceleration. It does allow the car to go faster in the same gear as compared to the smaller tire but may be a bit slower to get there.

[Locust]

Originally Posted by RT-BRZ

The slightly wider tire increases the total diameter of the tire when using the same sidewall ratio. The larger diameter tire has the effect of reducing the effective ratio of the rear gear ratio in use. So, the 4.10:1 gear may end up being 4.05:1 effectively. (I haven't done the exact math but the principle is there).

A lower numeric rear gear ratio means less effective acceleration. It does allow the car to go faster in the same gear as compared to the smaller tire but may be a bit slower to get there.

No I understand that but the diameter difference on same size wheel between a 245 and 255 seems pretty negligible.

[RT-BRZ]

Originally Posted by Locust

No I understand that but the diameter difference on same size wheel between a 245 and 255 seems pretty negligible.

You aren't wrong. I don't want to get into a big argument with anyone but it's difficult to imagine that a .05 impact to gear ratio will make enough difference generally to make it matter. Course variations could offset this kind of difference.

The 245 tire diameter in this case is 24.7" versus 25" for the 255.

[strat61caster]

Originally Posted by nathand

Is the 22mm FSB the undisputed way to go vs something smaller with the same spring rates front and rear and stock diff and stock rear bar?

Preference, and not all bars are created equal, there's overlap between the 20mm-22mm bars depending on hole settings and mfgr, whiteline generally regarded as stiffer then Perrin in same size. Don't forget the 25.4mm bars are hollow so they're not necessarily a bunch stiffer then a solid 22mm.

From Karcepts website;
OEM Toyota 86 Front Sway Bar (18.0mm Solid) = 191 lbs/in
Aftermarket 3 Position 20mm Solid Front Sway Bar = 282-364 lbs/in Range
Aftermarket 3 Position 22mm Solid Front Sway Bar = 357-461 lbs/in Range

Wong/ProParts car was on a 25.4mm Megan FSB, many others on Perrin 22mm iirc (Chang/Lugod were), heard WL 22 was too stiff, my WL20 was a pita to adjust.
Or just buy the Karcepts bar.

Originally Posted by Locust

No I understand that but the diameter difference on same size wheel between a 245 and 255 seems pretty negligible.

Falken RT660 Diameter;
245/40/17 24.8"
255/40/17 25.1"

Yokohama A052 Diameter;
245/40/17 24.7"
255/40/17 25.2"



Worth about 1mph at rev limiter (7,500-7800)/2nd gear (ratio of 9 gets you to ~60mph) according to this calculator and rough guess n check;
https://www.omnicalculator.com/everyday-life/rpm

[3k1n]

Hi everyone, I'm a Novice driver in the STX class. I have about 3 autox events under my belt with a handful of local HPDE events. I want to start thinking about making adjustments to my coilovers (rebound), tire pressure and sway bar settings. I know all of these things are very dependent on the driver and driving conditions but just wanted to generally understand what kind of setup folks in the STX class are running. To give you a quick and dirty breakdown, my car has the following mods:

HKS Hypermax IVGT coilovers (6kg Front 4Kg Rear)
Whiteling front and rear swaybars with adjustable endlinks (22mm front 16mm rear)
245/40/17 Bridgestone RE71R
Front Camber -2.5 degrees; Zero toe
Rear Camber -2 degrees;Zero toe

So really just wondering as far as dampening how stiff/soft do you run, sway bars hard/soft setting, tire pressure etc. Again, I know that alot of variables that go into this stuff but just wanted to get a baseline on how I should be making these adjustments. Appreciate the help guys!

[strat61caster]

Springs/bars/damping are all tied together, only someone with a similar setup will have a relevant starting point so ask Sam or whoever sold you the setup, sounds similar to a few other East coast cars I've seen posted. Otherwise test, change, observe, rinse, repeat.

Throw another degree at the front camber at least.

[Breezio]

4.1 final drive to 4.3 is nearly a 5% change.
That allows me to run the slightly taller (around 1%) and wider tire and still have faster acceleration (strictly based on gearing) then a 13-16 car. Plus helps me get back a small bit of max speed in 2nd gear.

I can't think of any reason a 17+ stx twin would want to run the 245/40 over the 255/40 tire.

[steverife]

Originally Posted by Breezio

I can't think of any reason a 17+ stx twin would want to run the 245/40 over the 255/40 tire.

As I said to the opposite situation...

...availability.

[cmiovino]

Originally Posted by 3k1n

Hi everyone, I'm a Novice driver in the STX class. I have about 3 autox events under my belt with a handful of local HPDE events. I want to start thinking about making adjustments to my coilovers (rebound), tire pressure and sway bar settings. I know all of these things are very dependent on the driver and driving conditions but just wanted to generally understand what kind of setup folks in the STX class are running. To give you a quick and dirty breakdown, my car has the following mods:

HKS Hypermax IVGT coilovers (6kg Front 4Kg Rear)
Whiteling front and rear swaybars with adjustable endlinks (22mm front 16mm rear)
245/40/17 Bridgestone RE71R
Front Camber -2.5 degrees; Zero toe
Rear Camber -2 degrees;Zero toe

So really just wondering as far as dampening how stiff/soft do you run, sway bars hard/soft setting, tire pressure etc. Again, I know that alot of variables that go into this stuff but just wanted to get a baseline on how I should be making these adjustments. Appreciate the help guys!

One thing that stands out is your front camber. For autox, having 4 degrees up front can really help. Everything else in your setup is generally standard for STX.

I wouldn't recommend an STX setup for a beginner with only 3 events under their belt. It's a lot of car and can be very fast if driven well. Just my opinion, but I think it's easier starting out with a DS setup BRZ, then moving onto SSC or STX, just as an example.

Generally, I'd say look more into how you're driving, your line, etc and less about your setup. If it's a smooth surface where you race, a bit stiffer than the street with your coilovers helps. The more cracks and bumps, the softer you want it.

Ultimately, tuning your coilovers for bound/rebound, swaybar settings, etc is only going to net you small amounts of time and would be for the more experienced. Just focus on driving for now.

[steverife]

Originally Posted by steverife

Ordered from Discount Tire Direct the other day and was told backorder and it was cancelled.

...but I went ahead and ordered from Discount Tire. Order went through, so we'll see if it gets cancelled, too.

Well, I was able to place the order and scheduled an appointment to get the tires mounted and confirmed the appointment, but no tires come appointment time.

[PLX92]

Originally Posted by 3k1n

Hi everyone, I'm a Novice driver in the STX class. I have about 3 autox events under my belt with a handful of local HPDE events. I want to start thinking about making adjustments to my coilovers (rebound), tire pressure and sway bar settings. I know all of these things are very dependent on the driver and driving conditions but just wanted to generally understand what kind of setup folks in the STX class are running. To give you a quick and dirty breakdown, my car has the following mods:

HKS Hypermax IVGT coilovers (6kg Front 4Kg Rear)
Whiteling front and rear swaybars with adjustable endlinks (22mm front 16mm rear)
245/40/17 Bridgestone RE71R
Front Camber -2.5 degrees; Zero toe
Rear Camber -2 degrees;Zero toe

So really just wondering as far as dampening how stiff/soft do you run, sway bars hard/soft setting, tire pressure etc. Again, I know that alot of variables that go into this stuff but just wanted to get a baseline on how I should be making these adjustments. Appreciate the help guys!

Welcome! Another MA local here, as a novice driver just getting your feet wet, focus on improving as a driver. Tire pressures would be where I'd start when you're ready, and that will be tire/course/setup depended really.

Alignment could use a bit more camber up front, and a touch of toe in - in the rear.

I've spent the last 2 seasons on STX prep level really just driving the car and fussing with tire pressures. Even then, I still feel like there's more time to be found in the seat.

You can usually find me out at Devens with various clubs. I haven't actually run with NER scca in the past year or so, but will start to attend now that the weather has broken. Hope to see you out there soon!

[3k1n]

Originally Posted by cmiovino

One thing that stands out is your front camber. For autox, having 4 degrees up front can really help. Everything else in your setup is generally standard for STX.

I wouldn't recommend an STX setup for a beginner with only 3 events under their belt. It's a lot of car and can be very fast if driven well. Just my opinion, but I think it's easier starting out with a DS setup BRZ, then moving onto SSC or STX, just as an example.

Generally, I'd say look more into how you're driving, your line, etc and less about your setup. If it's a smooth surface where you race, a bit stiffer than the street with your coilovers helps. The more cracks and bumps, the softer you want it.

Ultimately, tuning your coilovers for bound/rebound, swaybar settings, etc is only going to net you small amounts of time and would be for the more experienced. Just focus on driving for now.

I purchased the car as is and unfortunately not feasible for me to remove the parts and go back to stock to qualify for DS prep. Thanks for the advice, I will stay focused on improving ad a driver first.