BBS RF521 Wheels - Si to CTR specs?

[cammyfive]

Hello, all. This is my first post in the CTR forum as I own/post in the Si forum. I enjoy my 2020 Si but plan on trading/selling it just prior to the end of production of the current gen CTR sometime next Spring (2021). I have or plan to have only a couple of pretty easily reversible mods on my Si (downpipe, swaybar, tune, intercooler, etc) that I will remove and go back to 100% stock prior to trade-in or sale. I have been eyeing the BBS RF521 wheels pretty heavily ever since I saw C&D add them to their long term CTR for winter duties. I LOVE the look and the fact that in the same size (18") they decrease the unsprung weight of the boat anchor Si wheels dramatically. After tax, I think they would be around $3500 for a set of 4 and I would just move my almost still new Michelin Pilot Sport PS4S over to them in the stock size (235/40/18). I haven't done a set of aftermarket wheels on one of my cars in almost 20 years so I'm a total newb when it comes to offsets and all of that. My question is, would the BBS RF521s in the correct specs for my current Si also work on my future CTR?

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[ez12a]

looks like there are only so many variants for that model wheel in CTR fitment. The 18x9 +47 seem like the best fit.

Wheels for the Si will not straight up bolt onto the CTR because the lug pattern is different. CTR uses 5x120 so dont plan on buying it for your Si and swapping it to the CTR.

P/N: RF521DBK

You'll also need a set of aftermarket cone/acorn lugs most likely.

 

[tinyman392]

Hello, all. This is my first post in the CTR forum as I own/post in the Si forum. I enjoy my 2020 Si but plan on trading/selling it just prior to the end of production of the current gen CTR sometime next Spring (2021). I have or plan to have only a couple of pretty easily reversible mods on my Si (downpipe, swaybar, tune, intercooler, etc) that I will remove and go back to 100% stock prior to trade-in or sale. I have been eyeing the BBS RF521 wheels pretty heavily ever since I saw C&D add them to their long term CTR for winter duties. I LOVE the look and the fact that in the same size (18") they decrease the unsprung weight of the boat anchor Si wheels dramatically. After tax, I think they would be around $3500 for a set of 4 and I would just move my almost still new Michelin Pilot Sport PS4S over to them in the stock size (235/40/18). I haven't done a set of aftermarket wheels on one of my cars in almost 20 years so I'm a total newb when it comes to offsets and all of that. My question is, would the BBS RF521s in the correct specs for my current Si also work on my future CTR?

Bolt pattern for the Type R is different than the Si. You'll need, at minimum an adapter to get it to work. The spec I'm seeing for the Si is 18x8 +43. Most don't recommend going below +35 for the Type R, so the adapters would need to be less than 8mm thick. It's very unlikely to find one that thick, and even if you did, I wouldn't trust it. My best advice would be to sell your current set of wheels on the Si and get a set for the Type R.

The BBS RF521 is available as an 18x9 +47 which is probably one of the better sizes for the Type R since it keeps a relatively high offset. Keeping an offset closer to +60 will minimize torque steer on the Type R. I'm running a different 18x8 +42 that has a small bit of torque steer to it (nothing that'll break your wrist, but it's noticeable to me).

 

[cammyfive]

Bolt pattern for the Type R is different than the Si. You'll need, at minimum an adapter to get it to work. The spec I'm seeing for the Si is 18x8 +43. Most don't recommend going below +35 for the Type R, so the adapters would need to be less than 8mm thick. It's very unlikely to find one that thick, and even if you did, I wouldn't trust it. My best advice would be to sell your current set of wheels on the Si and get a set for the Type R.

The BBS RF521 is available as an 18x9 +47 which is probably one of the better sizes for the Type R since it keeps a relatively high offset. Keeping an offset closer to +60 will minimize torque steer on the Type R. I'm running a different 18x8 +42 that has a small bit of torque steer to it (nothing that'll break your wrist, but it's noticeable to me).

Thanks for the insight. I think it's best I hold off purchasing them until I get a CTR. I was hoping they would work on both models with no fuss.

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