DocWalt's 2022 WRB BRZ

[Code Monkey]

I will be up for one.

[DocWalt]

Installed the GP Sports "rear traction member collar" aka the "traction mod" that reduces the rear anti-squat for a more compliant suspension and better ability to put power down. Initial testing on the street says it does all of that very well! The car rides better and seems to settle into the road better on corner exit. There's a particularly bumpy intersection I drive every day that I couldn't accelerate out of hard on stock tires even in 2nd gear and now it just squats and goes. I can actually use first gear now without totally roasting the stock rear tires too on regular roads, so that's a marked improvement. Definitely curious how it does in performance driving!





I also installed the Perrin 16mm rear swaybar and made some DIY end links that I offset using some round tube and washers to fine tune the alignment to not bind the joint nor have the end link hit the control arm. Nothing too exciting to report here, but definitely excited to test these changes. I actually installed the end links last week and drove to work with the OEM rear bar all week, the non-OEM rear end links also seemed to make the car ride better, go figure not being all bound up helps a lot with ride quality.

[autoracer86]

Nice to hearing your opinion on the traction mod. That one has been on my list for awhile now

[DocWalt]

I did an autocross yesterday with Motorsports NE at MetLife stadium. The recent car changes have been... simply put, incredible. I took top PAX (non-SCCA event using their own PAX) and fastest raw time over a well driven GT4 RS, I took second using SCCA PAX, so that's a pretty darn solid result.

The anti-squat changes are a HUGE improvement, it's frankly kind of mind blowing. I would definitely recommend the traction mod for anyone that can do it within their rule set. The improvement in power down is really hard to describe, but it's really sort of mind blowing how early I can roll on the power now and not worry about the car getting unsettled over bumps or slightly imperfect inputs. I was so late to power on my early runs because it was just so settled and forgiving versus how it was before.

That said, the traction mod brings with it some setup issues. I went ~30% stiffer on the rear swaybar versus stock, but in practice it's likely more with the stiffer bar bushings and better end links, and that nearly perfectly compensated for the geometry changes creating a balance change. So you definitely need to plan ahead and plan on stiffer rear springs or swaybar to get the same steady state balance back now that the rear end is so much more stable and planted.

We made zero setup changes all day (not that we had time anyway since it was 3-4 minutes between runs which is pretty tight) and it was SUPER dialed right from the get-go.


Related, but not? I measured the wing angle change between the two settings, ~1.5 degrees between the two settings. I left it in the lower AoA position for now until I do some front aero.

Here's my fastest run from yesterday:

Here's my codriver's fastest run from yesterday (I'll spare him the embarrassment of naming him haha):

Some random photos of yesterday's excitement!









and a quick outside video of my codriver on course, the intake noise when it's near rev limit or on the rev limit is *insane* sounding and a lot of folks came up to me to make sure my car was OK, haha

[autoracer86]

Thanks for the write up. Making me really want to get one of those traction mods!. Great videos and congrats on the win. It does look like the rear end is more stable compared to older videos.

[DocWalt]

Off to NNJR at Metlife Stadium for my final event of the year, it was warm enough and we got 6 runs (or in my case 8 after some re-runs) and the car was a blast. Just some small setup tweaks since last event and the car is awesome. Sadly, I coned away my PAX winning run on my last run. Annoyingly, where I hit cones, I did those sector times clean earlier so the pace was definitely there. I have some more development work to do before next year, but hoping to at least be in the hunt for PAX wins even with the much harder XA PAX (even if XA PAX is too soft for what it is...) Considering lots of other competitors weren't nailing one sector that I was and therefore giving up nearly half a second to me, I need to find pace in the car for next year!
Had a friend help warm tires and give setup feedback, it's been half a year since he drove an autocross so he made some mistakes and under drove a bit, but had a blast and it's always a great time to codrive with friends.

Here's my fastest run, but dirty:

Here's my fastest clean run, still third in PAX:

My codriver's fastest clean run:

[DocWalt]

I got my splitter blade for next year, just waiting on the brackets. Seems like a pretty nice product so far! Not too heavy, which is good.

[DocWalt]

Designed an intake snorkel like the GR Cup cars. No clue if it fits first gens, *should* fit second gens but haven't had a chance to pull my bumper and triple check my work. It fits the airbox fine anyway, with a bit of weather seal tape.

I designed it to maximize the air intake area into the box while still using thin foam weatherstripping (1/16" thick) and mounting using the OEM grommet.


STL here: https://drive.google.com/drive/folde...9X?usp=sharing

[DocWalt]

Installed the Racebred splitter last night/today. I made it really hard on myself by wanting to keep the stock undertrays so I could drive the car without the splitter installed, I succeeded though it's a lot harder to install/remove the splitter now (still pretty quick). The silliest part is that I'll probably still mostly drive the car with the splitter on anyway, it doesn't really scrape on any of my normal roads.

[Petah78]

Hi, i noticed that you have the OE STI front lip installed. I am about the tempt the install this spring and have been reviewing the install instructions and it calls for the removal of the front bumper for the install. I think you have to remove the lower black piece and the grill, can you confirm if that is actually required?

Thanks.

[DocWalt]

Originally Posted by Petah78

Hi, i noticed that you have the OE STI front lip installed. I am about the tempt the install this spring and have been reviewing the install instructions and it calls for the removal of the front bumper for the install. I think you have to remove the lower black piece and the grill, can you confirm if that is actually required?

Thanks.

I didn't remove the front bumper, in theory you "should" remove it so you can drill out the backing piece of the bumper (behind the lower gray piece) so the rubber inserts can get more of a bite on things, but it's been fine for me even hitting cones and such.

[DocWalt]

My wife bought my old RX-8 back, so my time will be a bit divided between two cars

[DocWalt]

Got my 17x10 ET48 Konig Ultragrams from Vision Speedworks a while back, finally got tires on (245/40R17 Yokohama A052) and test fit yesterday with my normal 13mm front spacers and no rear spacers. They look great and the fitment is on point. The clearances in places are... snug. The clearance at full lock to the tie rod is nearly non-existent at ride height, in bump it would touch. I ordered some steering rack limiters to make sure it doesn't touch.











Rear clearance to the fender tab is VERY close when the suspension compresses, but it does clear. Ideally I'd have a RUCA to pull the top of the wheel in, but here we are haha.










The front clearances are a bit easier, especially with the spacers. That said, the tie rod is VERY close.

[autoracer86]

man your car looks awesome !