timurrrr's GRRRR86

[Krokodil]

Originally Posted by timurrrr

After I installed gen1 CSG TEIN Flex A's on the gen2 along with 245/40R17 RT660 and drove around the Lawrence Expressway exit of Hwy 101 South, I couldn't believe how loud the front tires were.
Overall the NVH of the front suspension is noticeably worse than it was on my gen1.

Maybe this is mostly because of these Falkens?
It is inexpensive grippy tire.
I am sure re-71r would be more pleasant.

[timurrrr]

Originally Posted by Krokodil

Maybe this is mostly because of these Falkens?
It is inexpensive grippy tire.
I am sure re-71r would be more pleasant.

These exact wheels and tires were transferred from my gen1 car along with the suspension. I'm comparing apples to apples.

In my personal experience, RE71R's are louder than RT660 at highway speeds.

[timurrrr]

A little behind on updating this thread.

The next thing I did was change the 17x9 +40 Konig Hypergram in the rear with 17x9 +45 Enkei RPF1 for the autox set, and checked the rear fender clearance.

Originally Posted by timurrrr

Tried Falken RT660 245/40R17 on Enkei RPF1 17x9 +45.
I have Verus RLCA and temporarily have coilovers from a gen1 car.
~1" drop vs stock, and -2.5º camber at ride height (so ~0.5º additional camber compared to stock arms?).

To check for clearance issues, I put the car on a fork lift, disconnected the rear end links, and fully loosened the spring seats (ideally I should have removed the spring altogether, but I didn't have time to do that).
Then I used a hydraulic jack to raise one of the rear wheels at a time, until the rear jacking points started to rise off the hockey pucks on the arms of the lift.

Remember that this may or may not represent what happens to your suspension in the real world.
If you only ever drive on mostly flat surfaces, and your spring rates are super high (autox'ers?), then the wheel may never go that deep into the wheel well.

However, if you have softer spring rates and for example you go down The Corkscrew at Laguna Seca, chances are your wheel will go into the wheel well as deep as the suspension geometry allows.

The other factor that you may or may not want to consider is sidewall flex of the loaded outside tire. I don't have enough data to say how much the top of a laterally loaded rotating tire moves compared to only vertically loaded static tire, or even in which direction.

Anyhow, here are the photos. Use your own judgement to draw conclusions.

1) First test, no adjustments vs gen1 setup.
The rear coilovers were already set up to have ~7 mm less compression travel than recommended by the installation instructions that came with them. Notice that some of the rubber "antennas" turned into J's.
Honestly I don't even remember if I jacked the wheel all the way at that point or stopped early. It's THAT close.



2) Adjusted the coilover to have 18 mm (!!!) less compression travel than recommended.
Now I can squeeze a caliper in between the tire and the fender liner.
Not ideal suspension travel, but now I'm pretty confident they won't make much contact if at all.
(Note: I adjusted the coilovers differently after that for different wheels and tires)



3) Photo of the fitment on the ground. Basically flush, but IMO a bit too aggressive.



Note that RT660's are very wide.
It's possible that other 245/40R17 tires on 17x9 +45 will fit perfectly fine.

Also worth mentioning that I didn't have time toe check inner clearance, which might also be a concern as we get into the higher numerical offsets.

[timurrrr]

Went to its first autox to Crows Landing a couple of days later. Below are some notes.

ASC sounds horrible. This was really the first time I was revving out the engine, and I was surprised it sounded worse than early NFS games. It also activated very obviously around 4k rpm, emphasizing how (bad) it sounds.

The linear tachometer in track mode took some time to get used to to effectively shift from 1st to 2nd.

It might be the course, but the suspension felt like it needs more setup. In the tightest section of the course I felt that the lateral transition was taking too long, upsetting the car. My setup was never too optimized on autox, but I don't remember this much of a "pendulum" feeling on the old BRZ with basically the same suspension.

I had a few power-on oversteers. Might be because of the "eager" tuning of the drive-by-wire throttle pedal, or because I previously sacrificed the amount of suspension compression travel and was hitting bump stops, or a combination of both.

The new car was attracting a lot of attention from fellow autocrossers. A few people didn't recognize me initially, because they remembered me by the old car haha.

Here's a couple of photos from the event:

[timurrrr]

Next up was installing a Brembo B-M4 BBK and getting the brake fluid changed to ATE Typ 200 (a.k.a. "ATE Super Gold").

Here's the write-up I did on the B-M4 thread:

Originally Posted by timurrrr

Got the yellow B-M4 kit for my Neptune Blue GR86.

First impressions: looks really good in yellow, strong Poorsche vibes.



The thing is MASSIVE, the photo don't do it justice.
Doesn't fit into a spare wheel that came with my Performance Package BRZ.




Two large gaps between the caliper and the knuckle, should allow more airflow into the rotor than PP Brembos:



Changing pads is a massive pain in the neck.
You need to take the caliper off, that bad boy is heavy, and the massive "wing" at the top of the caliper makes it harder to just hang it off a metal hook or something like that.
But before you take the caliper off, you need to break the slide pins loose:



You have to use a punch and a hammer to mover the slide pins out, can't just use pliers like I could with PP Brembos.
The spring clip is very stiff, and my fingers got really tired as I was trying to pull them the first time. Didn't get much easier the second time.

Maybe I'm doing something wrong, but my initial impression is that it's a bad choice for someone who would want to swap the pads frequently.

Also, the calipers got really dirty after I changed the pads.
It was so much easier with PP Brembos!..

The kit comes with stainless steel brake lines that that have a rubber bracket to hold it against the strut:



The brake line can slide with little resistance up and down that rubber bracket, so if you're really unlucky the brake line might start rubbing against the wheel.
I guess I'll be checking the brake line position during each wheel change.
That's a strange design, tbh.
Curious if anyone was able to use PP Brembo rubber lines instead?

[timurrrr]

In preparation for the first track day

• Replaced the factory transmission oil with Red Line MT-90,
• Replaced the diff oil with Motul Gear Competition 75w-140,
• Swapped the brake pads to CSG C1 front / C2 rear,
• Put on my other set of wheels with GT Radial SX2 225/45R17 on them

[timurrrr]

Spent the last couple of evenings before the first track day setting up data logging. Made a harness reusing the ASC connector, so no more ASC annoyance.

Documented my findings on GitHub:
https://github.com/timurrrr/RaceChro...b/ft86_gen2.md (wiring and CAN data mapping)
https://github.com/timurrrr/RaceChronoDiyBleDevice (DIY device to acquire the data and send to RaceChrono)

I then spent some time in the paddock right before my first track session making some last-minute sanity checking for the data logging with ignition on but engine off. When it was time to start the engine and go to the track, it went full DeLorean from Back to the Future: threw all the lights on the dash and just died... Turns out I discharged my old Braille battery!

I didn't have a battery tender with me, but luckily a few of my paddock neighbors came to rescue and helped me push-start the car. A bunch of people later asked me how come a brand new car needed pushing...
I missed the first session, but at least the car was back running.

All dash lights quickly went away, except for the check engine light.
I learned that if you press the "back" button on the steering wheel to dismiss the "Check Engine" warning, it will show up again in a couple of seconds with a chime.
However, if you enable Track mode, the warning will stop bothering you...
Which I guess also means that if a real issue happens in Track mode it will NOT warn you other than lighting up a light? Strange design.
The CEL and the warning both went away after a couple of track sessions.

Impressions about the car:

• Clearly a couple of seconds faster than gen1.
• The stock exhaust is so quiet that without ASC I couldn't really hear the engine with the windows down and helmet on. My first attempt at a fast lap I under-revved during a heel-toe downshift to 2nd and went pretty sideways into T7.
• I had to set up the "yellow zone" to start at 7000 rpm to get enough of a visual alert that it's time to upshift. Yes, I didn't really hear the engine even approaching the red line.
• Same power-on oversteer issue that I've experienced at autox. I had some doriftos going towards the concrete wall on the outside of T11, those were a bit nerve-wrecking.
• I recorded 261ºF oil temperatures during one of the sessions (OEM oil temperature sensor) but other sessions the peaks were 250–255ºF, with the oil temperatures fluctuating between 240ºF and 250ºF throughout the lap. It was ~70ºF ambient, a mix of sunny and overcast, and windy at times.

Here are some photos:






and an onboard of my fastest lap of the day:

As it was more of a shakedown day, I didn't push too hard, and my optimal lap was over a second faster than my fastest lap of the day.
But that was enough to score a P2 in my class, and P1 was out of reach (big wang!), so I didn't really need to go any faster anyways.

[timurrrr]

After the track day I went to check if 225/45R17 SX2s on 17x9 +40 don't have as much of a clearance issue as 245/40R17 RT660 on 17x9 +45, and indeed I was able to dial back some of the compression travel:

[timurrrr]

After the track day I went to check if 225/45R17 SX2s on 17x9 +40 don't have as much of a clearance issue as 245/40R17 RT660 on 17x9 +45, and indeed I was able to dial back some of the compression travel:

[timurrrr]

Cut the tow hook covers to fit the Raceseng tow hook in a tidy way.




Forgot to take a photo of how I trimmed the black part, but that one is easier to figure out.
It's the blue piece that had a steep slope relative to the shaft of the tow hook, and required non-trivial cutting:

[timurrrr]

In preparation for my first track night, I replaced the hideously dim yellow halogen interior bulbs with cool white Sylvania LEDs from O'Reilly's.
I mean, who doesn't want some more "cool" in their car?

Hard to show that on pictures (so I won't even bother), but it's so much pleasant to look for something in the trunk at night now that it has the 168 LED in it!
The 168s are about right as welcome lights at the bottom of the doors.
I used the slightly dimmer 194s for the map lights in the interior, but they turned out to be a bit brighter than I'd like. Maybe if I find a slightly dimmer light I'd switch, but it's not that big of a deal right now.

These LED lights should also consume less energy than halogen bulbs, so I'll be less likely to drain the battery while unloading the car in the morning of a track day or autox again

Picture of the packaging for reference:

[timurrrr]

First track night!

The car felt more stable with the increased rear compression travel.
That being said, I don't need to downshift to 2nd at Thunderhill East, so it wasn't exactly an apples-to-apples comparison.

Oil temps were reaching 262ºF in the afternoon (~100ºF ambient) and 257ºF in the evening (~86ºF ambient).

Note to self: for the next track night, get underbody glow.
A lot of people installed those on their cars, and the photos from the night session were wild

Here's a couple of photos by Scott Grasso and one by Andrew (koi.flow on IG):





Onboard:

[timurrrr]

Finally received the Titan 7 T-S5 in 17x9 +47 (2022 spec) that I'll be running in the rear, and mounted a fresh set of GT Radial SX2 in 245/40R17.
Previously the 86DC regulations only allowed at most 225s in my class, but they've just updated the rules to allow 245s.
Hopefully no more overheating of the tread in half a lap!

Kept the 17x9 +37 (gen1 fitment) in the front as I already had a set.

-3.somethingº camber in the front, -2.5º in the rear with RLCA, ~1" drop all around.
Went for a mountain drive and didn't hear much/any rubbing, will inspect the fenders next time the car is on a lift.




I'll be using Falken RT660 245/40R17 for autox. I believe RT660s are slightly larger than SX2s of the same size. Will be using the RT660s with the exact same wheels (T-S5 17x9 +37 front, +47 rear), so I guess if I set the coilovers up to avoid rubbing with RT660s, the SX2s will not rub either.

[timurrrr]

More cool stuff just came in!