LexLight

I noticed none of the newer RC F's have bracing. The TE does not have, Carbon Package ones do not have. The Fuji Speedway from 2021 does have, and all 2021 models do have.
Why is Lexus removing the bracing for no reason ?

I have included all the timestamps in the embeds so that video will start right where they showcase under the hood of the RC F.

2023 Track Edition Japanese variant called as "Performance Package" as it has Carbon Ceramic brakes.

Look at the firewall bracing, it even has provision but there are no strut bars.

2023 Carbon package
No provision at all its all clean

2023 Track Edition
Again no provision at all.

Now look at the

2021 Fuji Speedway

2022 Fuji Speedway

Ever since they added the Touch screen from the IS they removed the bracing from what I can see, unfortunately I cannot find any new video on the RC F 2023 or 2024 model years in North America. All the press cars have Track Editions only or Carbon Package, I'm curious to see if they removed in the normal RC F with Premium Package or not.

And the only car I found was in Europe, Germany, it also has the Auto Mirrors like Japanese RC F.

2023 RC F Premium Package
You can clearly see there's no bracing nor the provision here.

IS 500 currently suffers from bumper sag. Multitude of reasons, there was a guy who did a lot of things like creating duplicate account on this forum and got banned in a thread (many folks in the IS forum knew the kerfuffle, to be fair his analysis is not poor so I'm leaving the article for those who are interested), his article is at Motorfrontier citing why IS 500 does sag due to usage of mild steel in the front rails and no bracing like RC F. GS F does not have bracing but perhaps it has High Tensile Strength strong steel and it never needed. But RC F is a track born car unlike GS F because IMSA Weathertech, GT3 RC F is entirely based off the RC F since 2017, they won many races plus they even are in the GTD Pro series too and they designed the model like this to have bracing since it's inception in 2015 but now they are cost cutting clearly.

IS 500 / 350 bumper sag could be due to other aspects like the poor bumper brackets but replacing them does not fix and many people in the IS 350 also experienced the same but it happens slower. Toyota / Lexus are still silent on this. Its 2024 MY and no word as people are awaiting TSB for a permanent fix (up in the air). Regardless, Lexus / Toyota removing the useful OEM factory bracing off the Track Born RC F is preposterous.

Thanks

Gerf

Edit: misquote.

05RollaXRS

The 4-point chassis brace delete has been discussed before. It is no big deal for the RCF as it is already really stiff so a little shock tower brace is not going to make a significant difference. I have it on mine, but I think it is a very small part of the torsional or lateral rigidity of the platform. The shock brace is not a big part of the RCF's rigidity unlike like the IS500, which starts off with a rather weak and soft chassis and Lexus did not do anything documented to improve the rigidity due to budget limitations. They ended up extending the nose 2 inches for the IS500 and put a heavy V8 upfront and did nothing to strengthen the front box. That has resulted in the front box sagging resulting in the bumper sag. Again, cost. Removing the shock tower brace is not going to cause the sag issue like it is happening for the IS500.

RCF chassis is about 50% stiffer as per Lexus documentation than the IS chassis and I own a 3IS IS350 F-Sport as well. The difference in stiffness is like night/day. You can see from the diagram below where you can see how much rigidity was added to the front bulkhead where it was thickened to almost twice of what the GS have.

My 2016 RCF has the shock tower brace and honestly, having it removed in the 2023+ RCFs will be a very slight difference in rigidity, if any as I think Lexus might have made something else stiffer and possibly it is not even an issue. Bumper sag is completely unheard of in the RCF because of the inherent stiffness of the chassis.

Look at this diagram to see how much metal has been added to make the steel stronger:

- Increased apron/bulkhead thickness over the GS/GSF chassis.
- Torsional rigidity beams running through the doors (hence the heavy doors) that prevent bending moments under hard braking or acceleration.
- Floor pan is about twice as thick as the IS because it comes from a convertible and also has cross members running across for further torsional rigidity.
- 10-point rear brace to stiffen the rear subframe
- Central floor gussets

ItzFilyO

Dang! My 23 RC F has a bit of bumper sag too. Not too bad, just a little more gap on the driver side compared to the passenger side, similar to the IS 500 I guess.

05RollaXRS

You are getting paranoid. Small gap differences are normal. A little flimsy aluminum 4-point brace in the 2015 - 2022 RCF is not going to have any significant impact on the structural rigidity of a 4000 lbs car. It takes a lot of reinforcement in the core of the platform to resist twist and bending moments. It might be a fitment issue for you as the reasons for IS500 sag is where the bumper gets droopy and starts to separate as explained in my post above. It is caused because of lack of structural rigidity in the platform where the nose was extended 2 inches creating a longer overhang and a heavy V8 with quite a lot of overhang with no additional structural rigidity added to the platform especially the front bulkhead, which has the highest stress.

LexLight

I can understand what you are saying, as I mentioned GS F never had any bracing. But also many V8s out there has some sort of engine bracing. Ford Mustang, Cadillac CT V Blackwing, Challenger has it internally. The reason I brought this up was, even Acura TLX Type S had some sort of reinforcements for the engines, Lexus on the other-hand touted as the pinnacle of dependable ownership is faltering with the 3IS 2021+ bumper sag and the RC F handled by silently removing features off - They axed that unique TVD first, later the Memory seats 2021 being last which I just learned, now they removed OEM provision option, they could have kept it at-least for aftermarket.

I got interested in the RC F because of the IS 500 purported issues, and was thinking over whether it's a good direction to move or not as I love my IS 500 and I need to prepare some funds and etc and time as well and wait for the IS 500 TSB as its a big decision. So meanwhile I was observing the RC F along with it's pros and cons, I found these and was shocked to see how pathetically Lexus is cutting the features off their premium top end F car and the only F car in their entire line for some chump change, the world's top automotive brand Toyota doing this. How did they decide to axe Lexus Memory - Steering column and Seat to be deleted off the Premium Package ?

Tell me you are kidding, can you show us some pictures..If it's true then I'm so done with Lexus as a brand, I saw newer RX getting dash separation problem and LS being dead husk and modern small hybrid engines with uber complexity, glitchy newer infotainment etc. So much so for the bulletproof word being thrown at constantly.

05RollaXRS

Yes, it had to do with cost cutting more than anything in the wake of rising inflation especially in Japan. Everything is getting very expensive and it is expensive to make cars in Japan. RCF is a niche product and does not sell enough volume to offset the cost increases. Lexus also cut the ambient lighting and the memory seats in the RCF. Our earlier RCFs have all of those things you and I mentioned and mine cost about $83K with all options. After the refresh, every year some stuff was taken off. These days it is $90K for a carbon fiber RCF, but does not have TVD, no memory seats and like you said, some trim levels don't have the auto steering adjustment as well. The 2023+ does not have the aluminum chassis brace as well, but I believe that is because Lexus might have felt it was overkill for a car that really did not need it.


I responded to his post. RCF does not have the bumper separation issue at all. Never heard it. Bumper separation is completely different where it first droops and then starts to completely separate. I have heard this a lot that RCF does not have the issue because of a flimsy little 4-point chassis brace. Truth is, it is not going to make a significant difference one way or the other for a 4000 lbs car and like in the diagram above, is attributed to all of the strengthening underneath. See my post above. He is looking at slightly uneven panel gap and that is a very common thing even for Lexus cars as well. I have noticed slightly uneven gaps in my 2019 IS350 F-Sport.

ItzFilyO

You're right Rolla, I think it's just my OCD getting out of control again.





















This thing looks sick A.F.!!

05RollaXRS

Cool. It does. That looks perfectly normal to me.

This is my 7+ year old RCF and gap still looks great, if you zoom in.

nigel821

iTrader: (2)

Your first and third picture do not look right to me.
Especially the first one where you see the indentations. That's telling me that the black bumper clip is either stressed or has cracked because there's no reason why you should see that upper part unless something isn't clicked in.

Try gently massaging or pushing to see if that gap goes away.

This is what mine looks like by the way you do not see those indentations up front near the headlight on the side.






-Nigel

ItzFilyO

I tried pushing it but the bumper doesn't move at all, it's held on there nice and tight. The car now has 3700 miles on it and it hasn't changed since the day I got it with just 13 miles.

LexLight

Sure inflation and post Covid the economy changes across do matter esp the fact that RC F volume is so low vs all other Lexus cars. Now if you see LC 500, it has quad bracing. And similar thin AL braces (not like the 4 point attachment from RC F but 2 individual rods) are there which connect firewall to the shock towers. The other 2 are very thick and connect the front end. Lexus did not change anything in the LC 500 since it's debut which is 500lbs+ heavier than RC F, and flagship of the Lexus brand as of now and note both RC F and LC 500 share top speed electronically limited which is 168mph same as GS F / IS F. Only 2UR GSE car that is locked to 148mph due to not having extensive F treatment is IS 500 , understandable.

Also RC F Track Edition is not cheap. It's LC 500 price point. So the luxury feature-set is going down in the RC F line clearly. And LC chassis is not just a Luxury boat either from the top speed plus LC 500 has GT racing versions too like GT3 RC F from wiki to quote - "The LC500 GT500 is a GT500 GT race car derived from the road-going LC500 for use in the Super GT from 2017 onwards. The car is the direct replacement to the Lexus RC F GT500, which competed in the 2014 to 2016 Super GT seasons.[38] The LC500 GT500 car made its début at the 2017 Okayama GT 300km,[39] and claimed 14 race wins of the 24 overall entered races from 2017 until 2019 (26 with the Super GT/DTM crossover events). In 2020, with the introduction of the new Class One and the revival of the Supra nameplate, the Toyota GR Supra would take its place in the GT500 category."


It's just sad to see how my interest has been watered down. 20K approx more than the IS 500 but have to let go of a lot of basic OEM bracing provision to basic luxury features while paying the inflated prices, I can live without TVD..They took off Ambient light and "Illuminated Entry System", In the IS it lights up the interior both front and back, then the pedal area, the door handles light up when you are near the car with the keyfob. Lexus axed that from the RC F. What's worse ? RC has them. Both the Lexus Memory and the Illuminated Entry System from what I can see on the build page, that's really bad, the F car does not have but the base V6 which has plastic valve cover 2GR-FKS and not the 2UR-GSE masterpiece. GS F used to have everything at 85K including auto folding mirrors and trunk. Too sad the American market voted by buying ES which killed off GS for good.

From what I can see only the LC 500 is currently not bogged down barring that afterthought infotainment system design in 2024 refresh, but damn that's 30-50K+ more than the IS 500 OOTD & too exotic vs RC F, even GS F and IS 500 to be fair as its a "Six Figure Car".

I second it.
The bumper clips are visible, not saying it's like IS 500 issue but the gap is visible. I do not have any gap like that on my IS 500 for now.

miop4000

The red car’s bumper looks like its sagging.

Pressure against the lower lip during delivery?

Happened to my new RAV 4 many years ago. Bumper clips replaced.

V8_Fan

My ‘22 RCF premium has all options down to illuminated scuff plates and weather pack, but no memory seats. I was a bit dismayed but it does have Carplay, which is more useful considering I drove the car 95% of the time and the alternate driver merely moves the seat forward 3 in with no other changes.

07LXgs350

The red cars bumper definately DOES NOT look right at all. I would take it back to the dealership and have them fix it.