'23 BRZ Manual Track Build

[X25]

Originally Posted by whataboutbob

I managed to fit 295/35R17 A7s square on a first gen, but it took some permanent modifications to the front fenders and the right amount of camber all around, lol.

Haha, I'm guessing you had more power to wield, too : p

I'm keeping the engine stock for sure, so I guess not much need for anything beyond 255-mm-wide.

Speaking of tires, Apex has just released +48 offset 17x9 fitment for rear!
https://www.apexraceparts.com/store/...brz-wheel.html

Sooner or later, I'll have to buy another set for spare tires. Perhaps this would be it : )

[Powersfrs]

Originally Posted by X25

Glad to hear you found the issue. I have not yet gotten into the ideal height discussions, but it's good to know checking on sway bar link interference is a 'thing'.

Looking forward to trying them out, but before that, I'll need to install the coilovers and the seats/harness. The only question mark in this is the Titan roll/harness bar. Here's hoping it either fits or mostly fits, so I'd not need to spend too much time on it : )

A7s run pretty wide, and that will also be an important test for clearances. I love A7s and looking forward to trying them out on the car, but I have a feeling that they might overheat a bit on track use; I might eventually switch to R7s or other tires as my fast set.

I read dozens of pages on the issue on the first gen and I’ve come to the conclusion that it’s maybe to much force on the electric motor and not rubbing. The rubbing I have is very slight. I think the g’s under cornering along with the angles that the suspensions changes into when hitting does g’s overwhelm the power of the eps.

[Krokodil]

Originally Posted by X25

Speaking of tires, Apex has just released +48 offset 17x9 fitment for rear!
https://www.apexraceparts.com/store/...brz-wheel.html

Sooner or later, I'll have to buy another set for spare tires. Perhaps this would be it : )

If ET42 Apex wheel works, what is the reason to get ET48?
I am asking because I am debating between these two fitments.
Thank you!

[X25]

There's a long discussion that you might have also seen under 22+ BRZ section, and they mention change in the rear design, making the ideal offset higher. This pretty much means +42 will be more likely to rub in the rear on the outside, and we're not maximizing fitment clearances like a +48 would.

If available, I'd prefer a +48, and we'll see if +42 will rub or require an aggressive roll.

[Krokodil]

By the way
I run into same problem with Cusco rear arms.
Looks like a bad design.
Raced x arms look better

[X25]

Originally Posted by Krokodil

By the way
I run into same problem with Cusco rear arms.
Looks like a bad design.
Raced x arms look better

Hmm looks like that Racer X design UCA would require you to remove the joint to make adjustments? That could be painful, too, especially since tightening joints often skew numbers, too; nightmare for the perfectionists : p

https://racerxfabrication.com/frs-br...r-control-arms

I'll keep an eye on it, and if it ever moves again, I have an idea on how to secure it (nord lock??).

[Krokodil]

Originally Posted by X25

Hmm looks like that Racer X design UCA would require you to remove the joint to make adjustments? That could be painful, too, especially since tightening joints often skew numbers, too; nightmare for the perfectionists : p

https://racerxfabrication.com/frs-br...r-control-arms

I'll keep an eye on it, and if it ever moves again, I have an idea on how to secure it (nord lock??).

Yes, it would.
And it cost more.
That is why I got Cusco.
Now had to keep eye on Cusco.

[Pat]

Originally Posted by X25

There's a long discussion that you might have also seen under 22+ BRZ section, and they mention change in the rear design, making the ideal offset higher. This pretty much means +42 will be more likely to rub in the rear on the outside, and we're not maximizing fitment clearances like a +48 would.

If available, I'd prefer a +48, and we'll see if +42 will rub or require an aggressive roll.

Correct. The 48 will allow wider tires in the rear without the need to trim the fender behind the little plastic aerodynamic feature.
Check out the Apex Race Parts fitment guide. It's great.
I ordered the 48 offset for all four corners. Then in the front I ordered spacers. One set of 10mm and two sets of 3mm. This will allow me to dial in just the right clearance all around while still using a square wheel and tire package. I'd rather not deal with spacers if I don't have to, but if I want a square wheel and tire package using 245mm tires, yet would prefer not to trim the fender on my brand new car, this is really the best option. CSG Mike and Apex suggested this route. I won't have my car until January(ish) to confirm.

[X25]

I'd personally just get the +35 for fronts to stay optimal. You'll likely need longer studs with +13mm spacer, and even then, your lugs will be leveraged much more; why bother? : ) The tires last much longer on this platform as well; I'd not worry about it..

I have a fender roller, and will roll it a bit for clearance. Even then, I'd much rather use the +48s, but it was not available when I ordered them.

Of course, what tire you put in also makes a difference.

[dreamwonder]

Originally Posted by Pat

Correct. The 48 will allow wider tires in the rear without the need to trim the fender behind the little plastic aerodynamic feature.
Check out the Apex Race Parts fitment guide. It's great.
I ordered the 48 offset for all four corners. Then in the front I ordered spacers. One set of 10mm and two sets of 3mm. This will allow me to dial in just the right clearance all around while still using a square wheel and tire package. I'd rather not deal with spacers if I don't have to, but if I want a square wheel and tire package using 245mm tires, yet would prefer not to trim the fender on my brand new car, this is really the best option. CSG Mike and Apex suggested this route. I won't have my car until January(ish) to confirm.

I when the Apex 42ET route. Opting to only use 245 tires that fit. Mainly to keep things simple. For example not having to put in new longer studs everytime the wheel bearing hub is replaced. Or the chance of forgetting to put in spacers on frequent tire changes (say tire rotation and the spacer decided to stick to the wheel on removal). If I use 255 tires from time to time, I do have a pair of 949 48ET wheels for the rear.

[Pat]

Originally Posted by X25

I'd personally just get the +35 for fronts to stay optimal. You'll likely need longer studs with +13mm spacer, and even then, your lugs will be leveraged much more; why bother? : ) The tires last much longer on this platform as well; I'd not worry about it..

I considered a different offset for the front. I really didn't want to use spacers. But my desire for freedom of rotation was greater than my desire to avoid spacers.
I ordered longer studs, too.
Are you sure there is more leverage on the longer studs? I thought they only provided a pulling force on the wheel, and the wheel/hub interface supported the vertical load as long as the lug nuts were tight.
And regarding tire life...well, that depends greatly on one's use case, doesn't it?

[X25]

Wheel's backface is mated with the hub's (rotor's) face directly, and nothing else is engaging for vertical load. Your stud will have a much longer moment arm (the point of mount of the stud on the hub vs. where the back surface of wheel starts and jerks the stud up and down as it hits stuff). Considering we don't hear failures, it should be fine, but it's definitely more leveraged now.

Since I have to deal with 345 wide tires at the rear of my other track car, everything feels very cheap in terms of tire options on this car. I'd be OK to leave a little bit of rubber life on the table : ))

[Krokodil]

I also calculated a need for 13mm spacer in front for 17x9 with 245 tire.
Surprisingly there are no 13mm hubcentric spacers for Subaru available.
Really do not want to go sandwich of spacers route.

[Krokodil]

Extended ARP studs was my first mod.