Gen 2 Autocross Classing | Write your letters!

[timurrrr]

Originally Posted by dragoontwo

I get ~94 for the first, and ~189 for the second.

That was quick, thanks!
Based on your profile info, that arm is from a 2022 BRZ — is that right?

So they moved the strut hole closer to the knuckle, interesting. I thought it was the opposite.
I noticed you measured the distance between two edges of the holes.
Did you measure the diameter of the holes too? I'm not 100% sure if they are the same on a stock arm or not. On the Verus arm, the three holes were of at least two different sizes, so I tried to measure center to center.

On your second picture, I see ~209.5 mm. I presume you put the 20mm mark in the middle of the first hole? Perhaps you've forgotten to include a third picture?

[Locust]

Originally Posted by strat61caster

I misspoke, it’s not a ball joint it’s a set of eccentric bushings in the a arm like a Miata.

https://www.whiteline.com.au/product..._number=KCA326

You could also do an aftermarket upper control arm like this one;
https://racerxfabrication.com/frs-br...r-control-arms

Given that the rear falls naturally close to them desired camber the whiteline kit should be plenty, if it is a pain in the ass to adjust.

Thank you so much. I'll bookmark em and keep this post in mind.

[timurrrr]

Originally Posted by timurrrr

Can someone measure precisely (±1 mm) the distance between holes on gen.2 stock RLCAs?

My measurements of the Verus RLCAs:
Knuckle bolt/Strut bolt 104mm
Knuckle bolt/ARB end link bolt 189mm

Originally Posted by dragoontwo

I get ~94 for the first, and ~189 for the second.

Someone who already has a GR86 just messaged me saying it's also ~94/~189 on his car.

[dragoontwo]

Yes, mine is a 22. It shouldn't matter what size the bolt holes are because I measured from outboard to outboard edge. Though I do believe they are the same size. Yes I had the 20mm lined up in the knuckle hole. It's not a great measurement because there's a slight bulge in the stock arm.

[timurrrr]

According to parts.subaru.com, 2022 Subaru BRZ uses 20250AL011, which was also used on 2015-2017 WRX and STI.

So perhaps we can just use whatever adjustable RLCAs were ST-legal on those cars?
Does anyone know of any?

[timurrrr]

I emailed Verus and if I understood them correctly they sell the exact same arm to WRX and BRZ buyers.
Now you know what to do if a 2015-2017 WRX or STI beats you

[RRslip]

I my opinion, it would go a long way for this community to reject this as a something that matters. If everyone does it, would a protest really happen? Will a PC really throw everyone out for making their motion ratios worse? I sure hope not.

[Kelse92]

Aftermarket parts are rarely going to follow the exactly letter of our rules… they have much bigger fish to fry than the ones in the tiny pool of autocrossers. I get following to the letter of the rules and all. But this is an incidental change with what’s available on the current market. Reminds me a lot of the bushing metal content discussion from last year..

[timurrrr]

Originally Posted by Kelse92

Drilling a hole is simple enough but I dunno, trying to make things simple

Drilling a 10/12 mm hole 10 mm away from an existing 10/12 mm hole without affecting the structural rigidity of a suspension arm doesn't sound very easy to me.

[cjd]

Originally Posted by timurrrr

Drilling a 10/12 mm hole 10 mm away from an existing 10/12 mm hole without affecting the structural rigidity of a suspension arm doesn't sound very easy to me.

update to an insert which can be flipped for gen1 vs gen2? Dunno. Silly but what can we do...

[dragoontwo]

Originally Posted by cjd

update to an insert which can be flipped for gen1 vs gen2? Dunno. Silly but what can we do...

Like a flip chip for mountain bike geometry...

[cjd]

Originally Posted by dragoontwo

Like a flip chip for mountain bike geometry...

"koni insert" is precedent? But some coilovers for the platform do this up front (the Tein SRC I had did). "Easy" to retrofit, simple part to make...

[dragoontwo]

To muddy this RLCA talk a bit, lets also add in the fact that I believe they pushed the subframe out by 5mm per side(remember they widened the rear track 10mm). By also moving the shock hole outboard 10mm on the RLCA they moved it by a total of 15mm compared to first gen(assuming no changes on top mount). By using SPC RLCA moving the hole 10mm inboard gets closer to first gen shock geometry.

Can we get somebody with a first gen to measure bolt to bolt on the rear shock top mount in the trunk? I can do mine when I get home.

[DocWalt]

Would also be nice to go bolt to bolt on the subframe too