Wheel fitment on the 2022+ Toyota GR86 / Subaru BRZ - System Motorsports
With the arrival of the new ZN8 / ZD8 2022+ Toyota GR86 / Subaru BRZ chassis, it was only right for us to document in detail our procedure for wheel fitment on the new chassis. While the previous gen FRS/BRZ/GT86 (ZN6/ZD6) conventionally utilized sizing ranging from ~18x9.5 +35 to 18x10 +44, the new gen GR86/BRZ is a bit more conservative in nature. After extensive measuring sessions and trial and error on our new car, we have accrued great data indicating exactly what it took for us to fit our “ideal spec” on this platform.
#systemspec GR86 with Volk TE37SL 18x9.5 +40 5x100, NArdo “Arms” Gray w/ 255/35/18 Neova Advan AD09!
Gen-2 GR86 equipped with #systemspec Volk TE37SL in 17x9.5 +45 on the infamous Weathertech Raceway Laguna Seca track. Equipped with 245/40/17 Falken RT660K. Weighing in at just ~17lbs/corner per wheel. Wheels can be found here.
Our GR86 equipped with #systemspec Volk TE37SL 17x9.5 +45 5x100 Diamond Silver, Exclusively available through us. Shown here with 245/40/17 Falken RT660K with no rubbing! Wheels can be found here.
Gen-2 GR86 equipped with #systemspec Volk TE37SL 17x9.5 +45 5x100 Magnesium Blue, exclusively available through us. Shown here with 245/40/17 Kumho V730 w/ no rubbing. This is our backup track setup shown and we are running a 10mm spacer in the front for a wider track width. Wheels can be found here.
Testing Gen-2 spec TE37SL 17x9.5 +45 5x100 Pressed Graphite w/ V730 245/40/17 x Diamond Silver w/ RT660 245/40/17 @ Laguna Seca. Worn out RT660 in 245/40/17 managed a commendable 1:44.36 while the new V730 ran a 1:44.8 on the first out-lap. Huge weight savings per corner with the 17” TE37!
Our customer Zach and his ZD8 2022+ BRZ equipped with #systemspec Volk TE37SL in Concave Face, 18x9.5 in Pressed Graphite!
Our customer Zach and his ZD8 2022+ BRZ equipped with #systemspec Volk TE37SL in Concave Face, 18x9.5 in Pressed Graphite!
Cory’s Gen-2 GR86 equipped with #systemspec Enkei NT03+M in SBC, 18x9.5!
Our client Peter and his ZN8 2022+ GR86 equipped with #systemspec Volk TE37SL in Concave Face, 18x9.5 +40 w/ 255/35/18 in Bronze!
Field-testing at Weathertech Raceway Laguna Seca, with #systemspec Volk TE37SL 17x9.5 +45 5x100 with 245/40/17 Falken RT660K + V730 Kumho. No rubbing!
By now, as many of you are well aware (simply due to the fact that you are reading this), the chief issue with wheel fitment on the new generation 2022+ GR86/BRZ is the presence of the rear fender “flare” and protrusion where the quarter panel meets the rear bumper cover, alongside front inner wheel-well clearance. Under the rear “flare” where the quarter panel meets the rear bumper cover tab, there is metal that is part of the chassis that severely inhibits fitting anything that is more aggressive than an ~18x9.5 sized wheel with an offset ranging from +35 to +45. While we empathize with customers and don’t necessarily agree with permanently modifying and cutting into a brand new car, there are definitely a few steps and precautionary measures that we took in order to fit our ideal spec on this platform: 18x9.5 +40. First and foremost: Adjustable coilovers. The ability to adjust and fine-tune the ride height has proved to be invaluable to us. Ideally, we would highly recommend coilovers with adjustable tophats and linear springs, as this would afford us more inner barrel clearance in both the front + rear, which is already lacking on the new platform. Coilovers with progressive springs will definitely lack front inner strut clearance so we do not recommend it when fitting this size, and instead go with a more conservative sizing approach. Ride height is a chief factor in determining whether or not a specific fitment will cause any fouling issues, and the ability to adjust the final set height can certainly mitigate and reduce any chance of rubbing both on the inside + outside if the car is setup properly by a professional. This post discusses in great detail the data we have amassed with the new platform, and we are excited to share this with our clients who wish to run our #systemspec sets.
Like many of our customers with the new 2022+ GR86/BRZ, Justin (see above) has equipped his car with our #systemspec Rays Volk TE37SL in 18x9.5 +40. This size is desirable, not only because it boasts a concave face which has become increasingly popular since the inception of the TE37, but also because this is the sizing that is incredibly popular with the previous gen GT86/BRZ (ZN6/ZD6), and we are finding that many of our clients are upgrading to the new gen. The desire to “re-use” previous-gen fitments will become more prevalent with our customers due to the cost-saving nature of recycling an old set they might have lying around, so we sought to document what it takes to employ this size. Below are some of the options we took in order to make the fitment work. Please keep in mind that the end-user assumes all inherent risks when choosing to modify their car; we are not held responsible for the modifications that you choose to do to your own car simply from the information provided in this blog.
Option 1: For us, compensating with a smaller sized tire, i.e. 245/35/18 or 245/40/18 allows 18x9.5 +40 to work on the street. This is a mild-stretch on an 18x9.5 width tire, but in our opinion it is still usable. We would not go any narrower than a 245 sized tire on an 18x9.5, as the stretch would become substantial if we went any smaller, leaving the inner and outer lip of the wheel dangerously exposed. Contrarily, a 255 or a 265 section tire would cause minor rubbing or require cutting of the rear fender at certain ride heights or full compression, unless further suspension modification is performed (See Option 2 below) or fender modification (See Option 3). As pictured above, our customer Justin only has adjustable coilovers installed - and has not cut the rear fender flare. It has been reported that he has not experienced any rear rubbing issues when taking the aforementioned measures of compensating with a smaller sized tire (245/35/18). This is likely the most cost-effective route.
Option 2: For those who are looking to fit larger than a 245-sized tire on 18x9.5 +40 in order to maximize mechanical grip, such as a 255/35/18 or a 265/35/18, a bit more suspension modification is required. Option 2 is for those who still do not wish to cut the rear fender/rear bumper tab, but want to take advantage of the benefits of running a 255/265 tire. On our 2022+ Toyota GR86, we are running Rays Volk TE37SL, in 18x9.5 +40 5x100 effectively with a 255/35/18 Falken RT660K all around. The base specification of the wheel is 18x9.5 +43 5x100 but we have added a 3mm spacer to effectively make 18x9.5 +40 in order to simulate our #systemspec TE37SL 18x9.5 +40, and what it takes for it to fit. The presence of the 3mm spacer will also afford us more inner barrel clearance on the front of the car which is severely lacking especially at full-lock at certain ride heights. Furthermore, the rear has also benefitted from the 3mm spacer as the inner clearance with the rear inner fender liner is already dangerously close to the inside of the tire. We are equipped with 2022+ GR86/BRZ KW Clubsport 2-way adjustable coilovers which come equipped with a factory camber/caster plate on MacPherson-style suspension setups, helper spring + linear spring combo. Additionally, we have equipped our car with adjustable Rear Upper Control Arms (RUCA) - as we have learned that on a multi-link rear suspension setup, dialing the the negative camber from the top of the rear upright not only reduces the inherent stress placed on the axles, but it also affords us more outer fender clearance due to the the way the rear geometry is setup and adjusted. Contrarily, dialing solely from adjustable Rear Lower Control Arms (RLCA) does not afford us as much adjustability as we are effectively increasing the track width by extending the RLCA and pushing the bottom of the upright and hub outwards, which not only places more stress on the axles, it also brings the tire closer to the rear bumper tab due to the wider track width. While additional outer fender clearance is still gained by adjusting negative camber from the RLCA, it is marginal and not nearly as effective as utilizing the RUCA. It is recommended to use the RUCA for the bulk of camber adjustment, in conjunction with the RLCA in order to fine-tune the final alignment. It is also important to note that when equipping the car with adjustable RUCA/RLCA, sometimes the factory toe arm w/ the eccentric bolt is not enough to “zero” out the toe, therefore; we recommend pairing it with a set of adjustable rear toe arms as well. Some aftermarket adjustable toe links will come with an eccentric lock-out kit, but for those who are dialing in more than ~-4 degrees of camber which is already quite excessive, certain aftermarket toe links may not have enough threaded adjustment to “zero” out the toe after the RUCA is adjusted inward or the RLCA is adjusted outwards. We essentially combined the factory eccentric bolt with an adjustable aftermarket rear toe link to gain enough range in order to “zero” out our toe to minimize tire wear. Although not required, we also have adjustable rear trailing arms installed to provide another degree of adjustment/movement in case we needed it.
As one can tell from the photos below, we have kept our rear fenders + rear bumper tab untouched. Even at full compression, we have not experienced any rubbing issues. It is important to note that with our adjustable RUCA paired with RLCA, we were able to achieve ~-4 degrees of camber which is what it took for us to not rub/foul on the inside and outside in the rear. The fronts are sitting at ~-2.5 degrees which came just from the factory KW adjustable camber/caster plates and a pair of camber bolts. If we took off the rear 3mm spacer (which makes 18x9.5 +43 effectively), we would rub on the inside of the fender liner at the shown ride height. Please keep in mind that all cars will be set-up differently, however; this is what it took for us to get 18x9.5 +40 effectively to work on our car. Other cars when set-up will produce varying results, so please be prepared to make any fine-tuning adjustments required, this is just what has worked for us and is proven for us. Please also modify at your own risk and own discretion. Although not required, the presence of adjustable aftermarket trailing arms would also be helpful in dialing the caster to move it away from the rear fender/bumper tab, subsequently providing additional outer clearance. It is important to keep in mind that different ride heights + different alignments settings + different tire sizes/brands will produce varying results that may not be consistent with the information we have documented, however; the information we have provided here should be a great starting baseline for determining what may work for another car.
To many, -4 degrees may be excessive on the street, however; the handling and turn-in response is improved when the front camber is dialed alongside the rear in moderation. When lowering the car on adjustable coilovers, The ZD8/ZN8 chassis may exhibit as much as -2 to -2.5 degrees of negative rear camber on the multi-link suspension setup just due to the natural static ride height with stock control arms, depending on the final height of the car. Conventionally, most would utilize adjustable RLCA to “zero” out the camber for even tire wear. Due to the presence of adjustable RUCA, we were able to squeeze a bit more top clearance in order to ensure that even at full compression, no rubbing is exhibited. However, by raising the car, we were able to get away with as little as -3 degrees of camber to make this fitment work with minor rubbing issues on the plastic fender LINER (not the metal fender/metal bumper tab). Slight trimming and convincing of the plastic wheel fender liner would effectively reduce any chance of rubbing. However, we wanted to account for extreme circumstances (i.e. track ride-heights / alignments) so we pushed the envelope to see what could be done without cutting into the car, and the results are shown below. 255/35/18 Falken RT660K with about ~-4 degrees of camber, achieved through the use of adjustable RUCA, RLCA, and toe arms. We also have adjustable rear trailing arms installed, and moved the wheel forward substantially to get it away from the rear fender tab as an extra precautionary measure. However, the bulk of the topwards fender + bumper tab clearance came from the RUCA. It is also important to keep in mind that dialing in too much camber from the RUCA will bring the inner tire/barrel incredibly close to the rear inner fender liner (as if it weren’t close enough already at 18x9.5 +43. Increasing the offset above +43 would bring it even closer. +40 seems to be the sweet spot for us). Everything has been done in moderation, and a great deal of trial-and-error was performed in order to document these details in case any of our clients wish to go this route as well. (Scroll down to see Option 3 if you do not want to run this alignment / do not want to upgrade to aftermarket RUCA).
Option 3: In order to run a 255/35/18 or 265/35/18 with 18x9.5 +40 with a moderate alignment without upgrading the RUCA of the car, you will have to cut the rear fender flare + rear bumper tab of the car. Please do so at your own risk. Due to the design of the new ZN8/ZD8 chassis, this is what it will take to fit 18x9.5 +40 effectively. Below, we have highlighted and circled in red a portion of the rear flare + bumper tab that is known to cause issues at this size. This is what we will need to trim in order to make this size work while preserving a moderate alignment at our ride height, with a 255/35/18 tire. It is important to note that the Falken RT660K is an extreme summer performance tire and conventionally runs wider than most 255/35/18 tires. It will fit like a 265/35/18 when compared to some other brands. Certain tires even at 255/35/18 & 265/35/18 may not require the modification that we are performing, however; we are documenting this entire thread to illustrate and exemplify what it took for us to make this work on our 2022+ GR86. The information provided in this entire thread should only be used as reference; please modify at your own risk.
After the rear was shaved, we also decided to shave the plastic “flare” for additional clearance.
Our customer’s 2022+ BRZ equipped with our #systemspec TE37SL in 18x9.5 +40, 5x100 in Magnesium Blue! This car is equipped with 255/35/18 with adjustable rear arms, and no cutting or rubbing issues.
Joey’s GR86 equipped with #systemspec Volk TE37SL x OG stickers in 18x9.5, with a 255/35/18 RT660K. Wheels can be purchased here.
Anthony’s GR86 with #systemspec Volk TE37 Saga S-Plus in FAce-4 Concave, 17x9.5 +46 5x100 Diamond Dark Gunmetal. Wheel details here.
Our customer’s 2022 GR86 on TE37SL 18x9.5 +40 5x100, Concave Face, w 235/40/18!
Our customer Chris and his ZN8 GR86 equipped with #systemspec Volk TE37SL 18x9.5 +40 5x100 in Mag Blue + Optional OG Stickers. Wheels can be found here.
Our customer Brandon equipped with #systemspec TE37SL in 18x9.5 w/ 265/35/18 on his 2022 BRZ!
Spaulding Jackson’s 2022+ BRZ equipped with Yokohama Advan GT Beyond 18x9.5 +45 5x100, in the elusive Machining & Racing Hyper Black finish, paired with 255/35/18 Advan Apex V601 tires. Fronts are equipped with a ~10mm spacer providing additional suspension and fender liner clearance. Alignment is -3F / -2R, with RLCA and rear fenders shaved.
Rays Volk #systemspec TE37SL 18x9.5 +40 5x100 Pressed Graphite on 2022+ GR86/BRZ. Equipped with 255/35/18
2022 GR86 equipped with #systemspec exclusive, TE37SL 17x9.5 +45 5x100 w/ concave face, White w/ OG Stickers. Wheels available for purchase here. 245/40/17 RT660K as equipped.
Enkei Nt03+M 18x9.5 +40 5x100 in “SBC” Special Brilliant Coating on our GR86. Wheels can be purchased here.
