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Tristor

Branka: Country Road Specialist ('17 BRZ)

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5 minutes ago, maurice said:

That's a pretty stiff setup, 7kg front and rear springs plus anti roll bars. I don't think anyone here is running such a hard setup for a dual use car.

I found my set of PS4's great on track but the grip fell off massively with 4.5mm+ tread still remaining. Still fine for road use though.

I have run a 9/14 with arb's and ran 7/8 with arb's for ages for dual use. The dampers make a massive difference to running the high spring rates though. I wouldn't fancy those rates on cheapie dampers! 

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1 hour ago, maurice said:

That's a pretty stiff setup, 7kg front and rear springs plus anti roll bars. I don't think anyone here is running such a hard setup for a dual use car.

I found my set of PS4's great on track but the grip fell off massively with 4.5mm+ tread still remaining. Still fine for road use though.

Yeah, I have just shy of 5/32nds left on them, which is in that range and they still work fine on the street but are definitely beginning to give up braking grip on track.  I noticed this especially coming off the straight into turn 4, where I need to brake from 92mph to around 35mph to make the corner, and in turn 7 where I need to brake from around 96mph to 30mph to make the corner.  I'm going to do one more track day on them to keep the variables as close to the same to understand my own driving skill improvements (hopefully improvements), then I'll be swapping them to the AD08Rs and get myself back on track in November maybe but December certainly.

To clarify, I am on stock suspension currently.  I am not going to replace the suspension until next year, that particular combination (RCE T2s + sways) is being DDed by a lot of folks here in the US by backing off the stiffness of the dampers a bit from the recommended starting settings provided by RCE.  I anticipate it'll be a little stiff on the street, but tolerable considering I don't commute to get to work so the car mostly is a weekend toy + grocery getter.  Those dampers are custom valved to match the springs, so should be fine as they're specifically intended as a high-quality entry to track coilovers that can be dual-used.

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On 10/8/2018 at 10:15 PM, Tristor said:

To clarify, I am on stock suspension currently.  I am not going to replace the suspension until next year, that particular combination (RCE T2s + sways) is being DDed by a lot of folks here in the US by backing off the stiffness of the dampers a bit from the recommended starting settings provided by RCE.  I anticipate it'll be a little stiff on the street, but tolerable considering I don't commute to get to work so the car mostly is a weekend toy + grocery getter.  Those dampers are custom valved to match the springs, so should be fine as they're specifically intended as a high-quality entry to track coilovers that can be dual-used.

Ah, sorry I didn't read that properly. Don't fit the sways and at the same time as the suspension, you may well find you don't need them.

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Here's the video of my first session yesterday. Other two sessions I haven't gotten figured out the overlay stuff yet. Dash cam records video in 10 minute or less segments and the timing doesn't align with the data logger, so it's a pain. Anyway, my spin is in the video.

https://www.youtube.com/watch?v=3Y8ahyBhz7k

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It looks like I forgot to update my thread here, but I did update the one over on the US forum.  So just a quick recap:

1) Had an AutoX on 10/13 and a track day on 10/14, was semi-dry to wet for both events and on shot tires, managed to have a fun time at the AutoX and learn a few things, on my track day I got back to a consistent 1:40ish lap time and dipped into the 1:39s despite track conditions and tire condition.  My instructor says my line is now near perfect some of the time, I just need to improve on consistency and then start increasing speed, primarily by learning to trail brake better and using throttle steer/lift-off oversteer to increase momentum through particular corners.

2) New tires, Yokohama Advan Neova AD08Rs.  These are 200tw and already feel much gripper than the PS4S, but are heavier.  Won't get to be on track with them until after the first of the year.  As a season closer I did a full inspection of the chassis, suspension, driveline, and underbody and torque sealed all the fasteners.  I also swapped over to Carbotech 1521 pads for street use, swapped my diff fluid for AMSOil, and bled my brakes.  I also leak checked all my fittings and the thermostats from my aftermarket transmission oil and engine oil coolers.  Everything appears to be in tip top shape for the stuff that matters.  I identified that I was missing one of the brake pad back plates in the rear, and that one rear fender liner is torn, and I broke the stupid cardboardesque transmission tunnel cover in the process of removing it.

3) Currently beginning mental prep for getting properly serious about learning how to tune my chassis and how to drive on track next year.  Right now I'm planning between 12-15 track days next year, more if I can schedule it in with work.  Have got a budget laid out that lets me get all the exhaust and suspension bits and goodies I wanted, including higher quality than OEM fasteners for when I get around to installing everything.  In addition I'm budgeting for a second set of wheels and three sets of take-off Conti racing slicks, as well as a set of rotors and two sets of track brake pads.  If I can squeeze it, I may also be starting in on quality carbon fiber body panels for more weight reduction and a further interior tear-down.  As part of all that I'm also doing research on suspension geometry tuning and learning how to use SusProg3D and working on a model of the suspension in the car, as well as continuing to seek advice from experts.  At the beginning of 2020 I'm expecting to begin considering which organizations and class spec I want to target for competing, as nothing I'm doing up till then should affect things too much for my likely targets.

Anyway, that's basically the update.  As of now there isn't much likely further to report until some time in February next year.

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I haven't updated this thread in awhile.  Quite a few things have happened since the last update, suffice to say I'll be in the shop this weekend and part of next weekend (assuming Vorshlag sends me a correct top nut for the rear strut mounts).  Here's what's been done since the last update, and here's what's ready to go on as soon as I get my top nut:

Installed:

  • CSG Spec C2 Brake Pads (Front) / CSG Spec C1 Brake Pads (Rear)
  • Castrol SRF Brake Fluid
  • ARP 3" UHL extended wheel studs all around
  • CSG Spec Racing Lug Nuts
  • TRD Door Stabilizers
  • PTuning Windshield Washer Reservoir Relocation Kit

 

Awaiting Installation:

  • Racecomp Engineering Tarmac 2 (7k/7k) coilovers
  • Whiteline WEK001 and WEK002 bushing kits
  • SPL Parts Titanium Series Rear LCAs
  • SPL Parts Titanium Series Toe Arms w/ Eccentric Lockout
  • Vorshlag High Caster Camber Plates (Front)
  • Vorshlag Spherical Shock Mounts (Rear)
  • Verus Engineering Side Marker Replacement Kit
  • Wheel Spacers from Motorsport Tech
  • APEX ARC-8 17x9 +42 BRZ-spec wheels

My plan of the moment for track alignment is -3.2 degrees camber in the front, -2 degrees camber in the rear, 10mm spacers in the front, 6mm spacers in the rear with 17x9 +42 wheels w/ 245/40R17 tires (Toyo Proxes R888R). I think this is where I want to start out on track this year while I'm waiting on take-off slicks to come back in stock to buy.

I've got full sets of 5mm, 6mm, 10mm, and 15mm spacers so I can play around some with alignment settings and still flush out my wheels.

 

I'll updated my OP too.  All the Whiteline bushings go in "tomorrow" (it's after midnight as I'm writing this here).

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Looks like you've been busy! Will be interesting how you find the camber. That is quite a lot for a car that's used on the road. I run 2.5 degrees negative on the front and find my tyres wear evenly. Not sure if 3.2 degrees is going to wear the inside edge of your tyres. Two degrees on the rear is no problem though. I've got the SPL rear aluminium lower arms. They are a lovely bit of kit. Think only the adjuster is titanium. 

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18 hours ago, Lauren said:

Looks like you've been busy! Will be interesting how you find the camber. That is quite a lot for a car that's used on the road. I run 2.5 degrees negative on the front and find my tyres wear evenly. Not sure if 3.2 degrees is going to wear the inside edge of your tyres. Two degrees on the rear is no problem though. I've got the SPL rear aluminium lower arms. They are a lovely bit of kit. Think only the adjuster is titanium. 

 

I've picked my camber settings mostly track focused.  I don't really "daily drive" at all since I work from home, but even then, I rarely drive unless it's spiritedly and for fun.  I'd run more camber than this, but I want to start here and see where things are for the tires I'm interested in using a pyrometer on track before making any more alignment adjustments.

All the bushings are in except the rear subframe inserts (Whiteline KDT922) because when I opened the package it had 1 extra of one part and was missing 1 of another part.  Everything else went pretty well though, only took ~9 hours of work in the shop drinking beer with my helper to get it all done.  Having access to a lift, a pole jack, a shop press, air tools, and a torch helped speed things along a lot.  Having a fridge full of beer probably slowed things down a bit.  But all in all, it went well, and the car feels great. I'm doing an alignment check on Monday with a buddy who works at a dealership, but it seems to track straight and no adjustable arms were installed yet and no adjustments were touched, so it should be alright.

Next Saturday, if all works out, I'll be doing the coilovers and arms, but I won't get to enjoy them until quite a ways later because I start work travel next Sunday and need to get a proper performance alignment before going HAM.

Yep, I'm aware the arms are aluminium and only the socket cap screws which lock the adjuster are titanium, but they call it "Titanium Series", so, I do to.

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6 hours ago, maurice said:

Do you think the door stabilisers do anything perceptible?

Yes, very much so.  On video from outside the car during runs you can see the doors flex.  This flex is reduced, and road noise is also quieter during street driving.  It's pretty clear to me that this chassis is pretty strong and stiff from the factory, and needs little bracing.  All the slop in the chassis is at bolt holes due to the design to ease manufacturing processes.  If you eliminate that slop, all the torsional forces in the chassis get directed into the weakest point, which is the door.  I didn't have the door stabilizers last year on track, and my door on the passenger side moved in alignment from where it started (confirmed from photos).

I'm working on finding a decent body shop locally (harder than it sounds, most body shops are scammy trash) that can re-align my passenger door now that I've got the door stabilizers in.

 

If I was prepping one of these cars for track only use and had the funds, I'd start by stripping it down to nothing, taking everything out, and having the chassis stitch welded, a cage welded in, installing the door stabilizers, replacing every subframe bushing with PBMs, all suspension arms with heims, and using spoon rigid collars in the subframe when I reattached it to the chassis.  I'd probably also do braces/locks on the steering rack and the diff cradle, and do solid mounts for the engine and trans.  The stiffer you can get the chassis and drivetrain, the quicker weight transfer occurs, the smoother it happens, and the more effective your dampers are at keeping contact between the tires and the tarmac.  It also minimizes power loss from slop.  Performance driving is only really about three things, which is managing tire temperature, managing tire grip, and managing weight transfer.  That's it.  If you do those things correctly you'll be fast. 

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Just a quick update, I've got the suspension tuned in and everything installed.  Went to the track on Easter Sunday, and by the end of my 3rd session I was 3 seconds faster than my previous personal best lap time, so I am very happy with the car and my own progression as a driver.  I'll be at the track again this weekend, weather permitting.

Car has significantly changed in how it feels on track, so I had to completely relearn the rhythm, but once I got it there I must say the car feels very good.  I have JDM STI motor mounts, JDM STI transmission mount, solid driveshaft center bearing bushings, and have done every single bushing in the suspension with Whiteline replacement hard poly bushings.  Rear LCAs and rear toe arms were replaced with the SPL parts arms, and I now have the RCE Tarmac 2s installed, everything is dialed in.  My alignment was basically perfect for the tires and track, confirmed by the pyrometer.

Current alignment:

Camber: -3.2F/-2.2R

Caster: +8 degrees

Toe: 0F / 1/16th inch R

Cold Tire Pressure for track: 31 psi

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