[Fitted9k]

I think my biggest question is should I be concerned using MY23-24 lowering springs given this change (already bought them due to being an impulsive person)

Do it in the name of science. Then come back and tell us if parts are interchangeable.

 

[DylanJZA]

Do it in the name of science. Then come back and tell us if parts are interchangeable.

Not much other choice lol; it's that or I leave it at stock height (ew). Not against coilovers, but I prefer mild springs for a DD.

 

[spike021]

Not much other choice lol; it's that or I leave it at stock height (ew). Not against coilovers, but I prefer mild springs for a DD.

I'm still curious how those are.

I've been running RCE (racecomp eng) Yellows on my BRZ for ~7 years now and they have a very modest drop (2/3 inch if that) but almost eliminate body roll, add a bit more stiffness on mid-range bumps but ride very well and tight at the right times.

I thought from what I've read so far, the GR lowering springs sound kinda similar, at least on paper, especially with the bit of understeer/body roll on pre-2025's. Although I'm waiting for a 25 so maybe that point is moot anyway.

 

[st165]

What's the full part number for the sway bar bushings?

48818-12440

I think my biggest question is should I be concerned using MY23-24 lowering springs given this change (already bought them due to being an impulsive person)

No concern, catalog still have the 23-24 lowering springs as available for 25. It allows you to buy the same springs officially for 2025.

I'd be curious to know if these are just supersessions or if they actually have any meaningful differences. Maybe @st165 knows.

Just confirmed that they are not supercessions. They are different parts. They might have changed it because of the 295ftlbs of torque. However...the 2023 Morizo used the "old" clutch too. So...can't tell

Also. For now, this is the most detailed picture I have of the duct from the diagram.

 

[DylanJZA]

I'm still curious how those are.

I've been running RCE (racecomp eng) Yellows on my BRZ for ~7 years now and they have a very modest drop (2/3 inch if that) but almost eliminate body roll, add a bit more stiffness on mid-range bumps but ride very well and tight at the right times.

I thought from what I've read so far, the GR lowering springs sound kinda similar, at least on paper, especially with the bit of understeer/body roll on pre-2025's. Although I'm waiting for a 25 so maybe that point is moot anyway.

I would have done the OE option if they dropped the rear, but several members reported having to cut the rears to match the drop up front which was not ideal to say the least. Given that, I went with the Eibach Pro Kits, but same idea ultimately.

And yes, RCE Yellows were lauded for being great. They took forever to release them for the GR86, so I went TEIN H.Techs instead, but it was a solid combo for me as DD.

 

[KanmuriDavid]

48818-12440


No concern, catalog still have the 23-24 lowering springs as available for 25. It allows you to buy the same springs officially for 2025.


Just confirmed that they are not supercessions. They are different parts. They might have changed it because of the 295ftlbs of torque. However...the 2023 Morizo used the "old" clutch too. So...can't tell

Also. For now, this is the most detailed picture I have of the duct from the diagram.
View attachment 30925

These are the revised bushings, correct?

 

[SpaceFolding]

It’s a reply to the above question about the matte black wheels on the premium plus 2025.

Thanks but slightly hesitating from the lack of information on the 42611-12F10 page and such a wacky description and no image. How can one verify this part number?

 

[Sleeper]

Would the roll center be that affected if the other upper/lower control arms were unchanged? The trailing link alteration would mostly affect anti-squat as they stated, that's clear as day, but lateral loading/roll center would be only marginally affected at best, no?

Definitely, will affect how the springs and shocks work also. It should be effectively (slightly) firmer if using the newer spec mounts with the older springs I would imagine.
The rest of the newer suspension parts are probably to correct that.

 

[kumarkarthikeyanwrx]

For the MY2025, there were quite a bit of revisions to the suspension as well as cooling. I have created this thread to document all parts that are compatible with MY2023 and MY2024 vehicles, pending actual confirmation. If any information is inaccurate, please let me know and I will address.

View attachment 30895

The ATF cooler will not be relevant to MY2023 and MY2024. The sub-radiator seems to provide auxiliary engine cooling, but it does not actively cool the transfer case. Quite honestly, it's better to get an aftermarket radiator as any cooler additions would require the MY2025 front fascia. If you are so inclined to retrofit the sub-radiator, see @st165's post below:

Sub-Radiator Part Numbers

The most interesting change is the transfer case cooling duct. Per Chief Engineer Naoyuki Sakamoto, this change will not solve the AWD overheat issues, but it should help.

Engine Service Cover with Duct: 51405-12070
Main Under Cover: 51410-12200

View attachment 30894

These changes are all made to help reduce squat and dive; therefore, reducing understeer characteristics mid-corner and on the exit of corners. The rear sway bar was likely changed to accommodate the new springs. The most important change is the rear trailing arm mount as it is an actual suspension geometry change:

Front Shock Absorber (LH): 48520-80832
Front Shock Absorber (RH): 48510-80C88
Rear Shock Absorber (LH/RH): 48530-80B99
Rear Trailing Arm Mount (LH): 48727-06060
Rear Trailing Arm Mount (RH): 48717-06030
Rear Sway Bar: 48812-12580
Sway Bar Bushings (x2): 48818-12440
Rear Coil Spring (LH/RH): 48231-12N20

View attachment 30893

Finally, some more bolt changes to add rigidity to the suspension and steering system:

Lower Ball Joint Bolts (x4): 90105-12429
Steering Column Bolt (x1): 90119-10A34
Rear Shock Absorber Upper Mount Bolt (x4) 90109-10194

the subradiator and transfer cooling duct, are either of these parts transferable to MY 2024 GRCs?

 

[spike021]

the subradiator and transfer cooling duct, are either of these parts transferable to MY 2024 GRCs?

The subradiator probably uses the ventilation from the new fascia. So you'd have to figure out how to route air to it otherwise.

 

[daverup]

New 2025 Transfer cooling might not be a year round good idea for everyone. Toyota is reacting to the heating problems and that's great. If you drive the GRC in really thick snow and slush and ice, that new scoop may become a liability. If you keep the old version for winter driving you avoid the possibility of the scoop catching a ton of slop and getting damaged.
As a comparison, the Focus RS OE cheap undertray was easily damaged, and had a couple of scoops built in. It was a problem that required aftermarket replacements for winter nastiness driving.
My 23 GRC OE undertray is still in good shape after winter driving, and because of my cooler climate I won't be trying to upgrade to a scoop tray.

 

[KanmuriDavid]

New 2025 Transfer cooling might not be a year round good idea for everyone. Toyota is reacting to the heating problems and that's great. If you drive the GRC in really thick snow and slush and ice, that new scoop may become a liability. If you keep the old version for winter driving you avoid the possibility of the scoop catching a ton of slop and getting damaged.
As a comparison, the Focus RS OE cheap undertray was easily damaged, and had a couple of scoops built in. It was a problem that required aftermarket replacements for winter nastiness driving.
My 23 GRC OE undertray is still in good shape after winter driving, and because of my cooler climate I won't be trying to upgrade to a scoop tray.

There was already a duct in MY23 and MY24. The difference is the addition of another one on the service cover (presumably), which you could easily switch out between seasons. Below you can see the zenki ducting.

Lucky for me I live in Texas and get no snow haha.

 

[daverup]

There was already a duct in MY23 and MY24. The difference is the addition of another one on the service cover (presumably), which you could easily switch out between seasons. Below you can see the zenki ducting.

View attachment 30934
View attachment 30933
Lucky for me I live in Texas and get no snow haha.

If the 2025 service cover with the NACA scoop are interchangable with the old service cover that would be ideal.
The duct on the 23-24 under tray isn't really a scoop and doesn't seem to accumulate winter slop.

 

[Fitted9k]

Thanks but slightly hesitating from the lack of information on the 42611-12F10 page and such a wacky description and no image. How can one verify this part number?

Wait a few months after vehicle comes out then toyota updates website with replacement/repair parts.. All the part numbers here are not available right now I believe around May 2025 part numbers should start to populate on toyotaparts website.

 

[GRCSupersonic]

@KanmuriDavid, thanks for all the info, it seems like more parts have been changed as we dig into the diagrams, it was different to change a few bolts to do the 24 upgrade but this, it's a whole different animal, at this point would be better to stick with the 23 or 24 as we speak and maybe traded it for the final edition when the time comes.

 

[KanmuriDavid]

@KanmuriDavid, thanks for all the info, it seems like more parts have been changed as we dig into the diagrams, it was different to change a few bolts to do the 24 upgrade but this, it's a whole different animal, at this point would be better to stick with the 23 or 24 as we speak and maybe traded it for the final edition when the time comes.

All in all, I don't think many of these are must haves other than the trailing arm mount and transfer case ducting.

I intend to get those two and the revised bolts for this year. The rest can be addressed by the aftermarket.

 

[Avari]

Slowly adding all of the 23, 24, morizo, performance, and 25 parts to one big sheet, feel free to let me know what else should be added

GRC Parts by year

 

[Mr. Toad]

Slowly adding all of the 23, 24, morizo, performance, and 25 parts to one big sheet, feel free to let me know what else should be added

GRC Parts by year

Thanks for doing this!

 

[zoeyrae]

I really hope it's not too much work to add the HUD as it's the only '25 thing I want.

 

[DylanJZA]

I really hope it's not too much work to add the HUD as it's the only '25 thing I want.

If swapping out the entire dash, windshield, and adding the HUD and wiring (potentially requiring a new sub-harness) doesn't sound like too much work lol.