A GT500 Racer In Detail
The Height Of Japanese Endurance Racing

It’s not every day that I get to feature proper race cars here in Japan. Sure, there are tons of time attack cars that I’ve pointed my inquisitive lenses towards, but factory-supplied, high-level race cars they are not. And to top it all off, the car you see here isn’t an old racer either – it’s a brand spanking new Lexus RC F GT500 that is currently competing in the Super GT championship. What makes this even more special is that usually race teams and manufacturers don’t really like disclosing or showing any information on their state-of-the-art race cars right at the beginning of the season, for obvious reasons.


That’s why it makes it even more special that Lexus Team Sard gave me the go ahead to shoot their #39 car – driven by Heikki Kovalainen and Kohei Hirate – on Fuji Speedway’s pit lane. Some rather stringent requests came with accepting this sort of shoot. First of all I had exactly five minutes to do the whole shoot in. Secondly, I had to agree not to show anything in the engine bay or at the rear of the chassis which would reveal suspension solutions/settings to competing teams. In fact, if I was to be very unprofessional and show even a snapshot of say, the carbon fiber air intake that sits on top of the engine, the team would get penalised by the manufacturer.


So there was no point in doing anything quite so silly – I was just happy to get the opportunity to spend some time with this car. And believe me when I say that you wouldn’t have benefited much from an engine shot, as it is so compact and sits so low that you can’t even see it! All you see is suspension arms and the pushrods lining them to the inboard mounted dampers, not to mention a labyrinth of neatly laid out cabling, piping and ducting. So with that explained, let’s concentrate on everything else I was allowed to snap away at.


And first up – before the wheels were put on the car – I had the chance to check out the carbon brakes that GT500 cars have been running in the series since last year. With the regulations coming in-line with DTM, this is a big change from the old steel set ups that all teams had to stick to up until 2013.


The Lexus Team Sard RC F runs AP Racing calipers all round, designed and developed for specific use in the Super GT series and fitted in a 6-pot configuration up front, and smaller 4 pots at the rear. Both are mounted behind the axle and in the lower quarter to help keep the unsprung kilograms as low as possible. Aside from the central vanes that take care of cooling the ventilated carbon rotors, the entire assemblies are shielded on both sides with carbon fiber covers that are there to contain the carbon dust, which is pretty nasty stuff.


With the wheels fitted – something that takes about four seconds per corner – the car was pushed out onto pit lane. The ‘start’ button was pressed on the timer and my five minutes began…


Much like every GT500 car of the last 20 years the recipe is the same when it comes to design. The overall shape is sort of kept and the roof remains as the only unchanged line in the whole road car to race car translation. Of course, with a bespoke carbon chassis that Toyota developed for this year’s season, there isn’t really anything that’s actually shared with the production RC F, but you get what I’m saying. Putting aerodynamics aside for now, what always makes these GT cars so appealing – and that goes for DTM ones too – is the way that the car’s body gets a hefty chunk of its lowest section removed, and then seems to be effectively pushed down over the wheels. That gives the typical wheel arch over the bonnet look, and just makes for a badass design for a lack of a better word.


The RC F’s front fenders are extended horizontally outward and shaped over the massive 300-section slicks that these cars run on. A series of louvers help channel away high pressure air from within the wheel arch to cut down on turbulence.


The car sits on massive BBS rims that BBS Japan custom created for use in this class. They measure 18×12-inch at the front while the rears are an inch wider at 13-inch. The Sard team use Bridgestone as their tyre supplier with a selection of special compounds and types available according to weather conditions.


Underneath the complex bonnet sits the turbocharged RI4AG 2.0-litre, four-cylinder built by Toyota Technocraft, abiding to the new regulations that call for the use of force-fed four bangers. Is it just me, or isn’t it really cool that Toyota are using the ‘4AG’ moniker for this engine? Despite its compact size it develops over 550PS with a 100kg/hr fuel restrictor fitted. No torque figures are quoted, but it would be a substantial number.


Up front there are a series of beautifully constructed and laid out air guides that take air from the grille and direct it towards all the coolers and radiators that are arranged within the car’s frontal area.


What blew me away was the fact that the RC F’s spindle grille that give the car its unmistakable look, is made out of carbon fiber. That is one complex shape, but then again Toyota is at the cutting edge of composite material production as they showed us with the LFA. This is just them showing off, and I love it!

Aerodynamics Come First

The aerodynamics are as advanced as they get and the side skirts – if you can even call them that – are just the tip of a very complex underbody section that helps the car stick to the asphalt at speed.


GT500 cars always have the coolest side mirror designs! They have to stick out quite a lot because of the actual width of the cars, so that creates the need to design something that doesn’t upset the flow of air too much.


To help cut down time when it comes to pit stops, Team Sard use Bray windscreen skins which simply peel away in layers when the car comes in. This keeps the bugs and other debris clear of the driver’s vision.


Back in January when Lexus kindly lent Larry and I an RC F press vehicle, it was the overall profile of the car that stunned me the most. It’s a very aggressively-designed coupe shape, and its translation over to GT500 racer has further emphasised this with a more supple and muscular stance.


The BBS wheels are a great match to the overall design. They are an instantly recognisable addition to the car and a detail that motorsport fans always like to see.


The 13-inch wide rear wheels run massive 330-section rubber, which is partly why GT500 cars manage to maintain so much speed through the corners. There is a rather big fender gap between the top of the tyre to the actual fender, and that’s probably something engineered for both aerodynamics as well as to account for suspension compression.


Seeing that the titanium exhaust passes through the passenger side of the car before exiting out the door, it’s a good thing the cabin has air conditioning or else the drive would pass out. I see where Under Suzuki got the inspiration for his side-exit exhaust now!


Here’s another close detail of the rear section of the right-hand side skirt where it aligns with the wheel arch. That is the cutest little canard I’ve ever seen, and I’m sure it’s there for a very specific reason.


This brings us to the rear section of the car, where the rest of the aerodynamics package extends onto both outside and deep underneath the car. It’s also where we’ve managed to get our name – Speedhunters’ Japanese webshop logo proudly displayed along with other important brands within the industry. Hashimoto Corporation are the guys that distribute Speedhunters merchandise within Japan and thanks to them we are able to see our name in a prestigious series such as Super GT.

The RC F GT500 Wins On Looks

Just look at that rear end! Curiously enough, both the front and rear lights are off a production car. Because of their LED technology they were given the green light for use on the race car as they were – and apologies for the pun – impressively light!


The trunk lid sports an integrated and extended lip spoiler and can be completely removed without interfering with the main wing stays.


Once you remove that along with the rest of the rear section you have access to both the dampers and anti-roll bars, which always need to be set up and adjusted at each race. They are mounted in-board like the fronts, damping the movements that the double wishbone layout transfers via the pushrods. The 6-speed transaxle transmission can also be reached from the rear – again why I wasn’t able to take any shots of this particular section.


The DTM regulations introduced last year also saw the GT500 cars move over to swan neck type stays for rear wings.


These are the way a lot of other race series are going, as they interfere less with the flow of air that is being used by the planes of the wings to actually generate downforce. Plus, they looks seriously cool, so there’s no real reason to fault them.


I’m a GT-R man through and through, but the RC F is by far the prettiest and most in-your-face car currently competing in GT500. It makes the NSX Concept look fidgety and the GT-Rs look, well… dated to put it mildly.


What do you guys think? I mean, for what GT500 lacks in actual variety compared to GT300, it makes up for with these beautifully-created factory racers.


I’m sad to say that the cockpit was also off-limits for shooting. Apparently there are some things in there that Sard didn’t want others to see – perhaps the seat position or other solutions that they are allowed to play with.


The reason I had to hurry up with the shoot was that all six RC F race cars entered in GT500 this year were due to have a group photo taken on the main straight.


They just managed to fit across the width of the track, then were joined by their respective drivers.


Nothing is quite as satisfying as taking a closer look at a race car and seeing how efficient mechanical and aerodynamic engineering is getting, and how innovative solutions continue to pop-up despite the countless rules and regulations that cars like the GT500 RC F have to adhere to. A big thanks goes out to Lexus Team Sard for giving me those precious minutes with the car and for the guys at Hashimoto Corporation for making it possible.

The question is, what other JDM race car would you like to see featured next?

Dino Dalle Carbonare
Instagram: speedhunters_dino



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Can you do a car feature on the Toyota TSO40 next?


apieceobacon that would be very very sick!


2.0 liter 4? I thought all the GT500 cars were running v8s?


other JDM race car would you like to see featured next?
Prius GT300? :p


Nice one Dino


Skyline Turbo Group C, please!


rally2727 apieceobacon I'll see what I can do. Last time I saw the car it was kept at TRD. No cameras allowed in that garage though...


Smiggins That was 2 seasons back


Dhikaz The least Prius Prius on the planet!


SS6K You mean the Gr. 5 one? Last time I was at the Nissan warehouse they didn't have it


"...the team would get penalised by the manufacturer." What type of penalisation are we talking about here?


speedhunters_dino Smiggins So all GT500 cars are restricted to 2 liters? Why?


Thank you so much for covering this Dino! I watched the whole series last year, but so far it's been tough finding any info/media for the 2015 season.  =)


roryfjohnston I'm guessing a financial one


Do i still have to say you did a great work? i always compliment you, if you ever get any better at this stuff people will start to say you're "cheating", lol
Awesome as always, i would only ask for a bit of GT300 on the next one, if you ever get the opportunity


speedhunters_dino Dhikaz Oh that'd be a hoot to see here on SH. And just imagine if Toyota goes full Mad Max and does a Prius i8 fighter for half the price!


Heikki Kovalainen? Heikki Kovalainen?! HEIKKI KOVALaINEN?!?! *faints*
Meanwhile, this feature just reinforces my love for this class. Even better is the fact that NISMO TV and another channel has recorded races and puts them on YouTube for free... and no country restrictions, too. Talk about binge-watching!!!


Subtle choice of words for this car's autobiography. Been a fun read.


Is that really the engine code?!?


Smiggins speedhunters_dino because GT500 now using same regulation like DTM if I not wrong.
SGT, DTM, and IMSA if I not wrong already make class 1 so they can race together. But now only SGT and DTM have race together. http://sportscar365.com/imsa/joint-dtmsuper-gt-races-planned-for-2017-2018/

turbo BEAMS ae86

this why i browse here..


speedhunters_dino Dhikaz I prefer to say "The most Un-Prius Prius in the world". :P


So Heikki Kovalainen has gone to Super GT...


Next JDM race care you say??? I'd like to see what the Japanese are up against now that the DTM cars are in the mix!!! You're right about the GT-R looking dated compared to the futuristic looking RC-F. The GT-R is the people's champ but that RC-F is gorgeous!


Great article, shame about not being able to shoot the really interesting stuff, but I completely understand why. Just as an aside, the reason the calipers are mounted behind the discs are so that the reactive force produced whilst braking acts upwards, instead of downwards. By acting against gravity (and the weight shift to the front axle) the bearings are put under less stress whilst subjected to the huge braking forces these cars produce.


speedhunters_dino SS6K I think he means the '82 'Skyline Group C' car: http://img295.imageshack.us/img295/5020/skylinegroupc3ff8.jpg


Can older cars be shown to the public now? I mean JGTC in depth. Would like to see their restricted zones.


I'd think that the swan neck wing pylons would be inherently less strong than the standard type, because all the downforce would be putting the pylon-wing mount points into tension instead of the compression of a regular setup.

Nice to see AC in a race car - I don't know how pros work in such a hot environment.


Ice Age they probably compensated for it with the direction of the CF's weave.  from what i understand from mulsannescorner's article, the swan necks came about because the smaller wing regulations caused them to look for ways to gain back the lost downforce and the swan neck proved to be the best way.


Ice Age Carbon fiber (what the stays appear to be made of) is actually stronger in tension than compression.


Bradders The real reason is weight transfer, instead of relieving any bearing stresses. The bearings are fine, I can assure you. When the car is slowed down by the brakes, inertia in the body transfers weight on the front tires. Because pneumatic tire is a load sensitive component, this leads to loss in total grip (all four tires) since the load on the rear tires has been reduced and it's not compensated by the increase in front axle grip.
Now if we configure the brake calipers so that the moment created by them is counteracting the dive, we can reduce front tire loads and increase rear tire loads when the brakes are applied. This then increases total grip and we can set the brake balance more towards the rear than in the case where braking moment is not utilized. This of course shortens braking distance and makes the rear more "tight" under brakes.
This is why the rear calipers are on the opposite side because naturally the chassis movement at the back is in the opposite direction - we want to push the rear down when braking.


oneisdifferent What you described sounds a lot like anti-dive suspension geometry.


jay8393 Yep! And a nice guy he is too!


@turbo BEAMS ae86 :)


ADimitriRoumeliotis Yes


UWerqxTeam_MJ Yeah super cool guy!


mbretschneider Thanks! I'll try some more cars for sure!


KyShro Check Nismo TV :)


UWerqxTeam_MJ speedhunters_dino Dhikaz It's Toyota, so it'll take them 10 years to build it ;) lol


LauriLeesmaa Depends who owns them


Bradders oneisdifferent Indeed, that's what is happening if the RC F has its suspension designed to induce anti-dive, which is sadly something we can't confirm from this post speedhunters_dino. If there's no geometry to support this I'd say the positioning is just because of some general stuff like suspension packaging, brake cooling conveniency, CoG etc. On a side note I should've used the term inertial load transfer rather than weight transfer but I guess it's easier to understand, weight, mass and load being so intertwined words. Weight transfers in anti-dive, inertial loads not so much.


All about keeping that bottom surface as clean as possible!


They've already discussed DTM cars in GT500 and vice versa....the only problem currently being that the Germans won't play ball because they know the GT500 cars would work them...barely breaking a sweat.


Ice Age I could be wrong, but I thought I read somewhere that the wing is actually being forced up when the car is in motion, not being pushed down. Please correct me if I am wrong.


Hit "post" too soon lol.
Was just going to add that the major reason is due to the tire war in GT500, whereas DTM is on a control tire.
The GT500 cars are easily capable of a race pace equivalent to LMP1 cars. They're bloody amazing


Sorry but that's wrong. The wing is shaped like an upside down aeroplane wing.
The downforce is caused by a low pressure zone which occurs because the air travelling bellow the wing has a longer distance to travel than the air travelling over the wing.
On a car, the underside of the wing is the critical suface (just like the underside of the car is a critical surface). Conversely, on an aeroplane wing, the top of the wing is the critical surface (hence why jets typically hang all kinds of extra gear below the wings...it has little to no effect on the wings ability to generate lift)


@speedhunters_dino, great feature!!
As for what else to cover...
Any chance you could do a spotlight highlighting some of the differences between the various GT300 packages.
I'm thinking along the lines of comparing a Euro GT3 machine vs traditional GT300 (like the Prius, CRZ, or BRZ) vs the new carbon monocoque cars (like the 86GT and Evora)


Twitch_6 Yeah, what I said doesn't make any sense after I thought about it. Low pressure under the wing and high above causing it to pull downward and pull on the supports. Thanks...


It kinda reminds me of the M4 from DTM


EvolveWRC It should, in 2017 (I think) they will be racing together ;p

Chris Nuggets

Glad to see Heikki still racing in a competitive and exciting series. Hope he can help Lexus shine in the GT500 category!


Chris Nuggets They haven't had the best of luck so far, but it's early days yet


_rafal EvolveWRC That would be the M6


Twitch_6 If I get the chance to wonder the pits like that again I will. Might get some dirty looks from the mechanics though haha


Wow! beautiful car!


Although those tyre sizes look wrong at the end...
"Bridgestone 300/[b]680[/b]R18 (front), 330/40R18 (rear)"


Ice Age Like anything structural, it doesn't matter if it's not as strong as another way of doing it.  It only matters that it's strong enough for the intended loads to do the intended task.  This is racing, and overly strong equals overly heavy.


Is it just me or that rear wing is wider than DTM cars???


Thanks for the article!  What are the other classes that are being raced in Japan?  Sanctioning bodies?  Is there somewhere that an English translation of the rules can be found?


it took me over 5 minutes to view and appreciate one photo...
and you managed to do well over 33 photos in just 5 minutes. in stunning quality and composition.

very well done Dino!


oneisdifferent Anti-dive suspension geometry will work no matter where the brakes are located though. Old Peugeot 106s had anti-squat suspension on the rear and they used drums!


speedhunters_dino As far as I know M6 will be racing in GT3 and similar series, not with these two (I haven't heard about DTM M6).


@Kart Works This particular car is in the Fuji-spec aero trim, which has wider rear wings.


John Evans the main sanctioning body is the JAF, they run Super GT, Super Formula, Japanese F4 and the like. If Dino is reading these, could we maybe get a Super Taikyu car in detail? Anything from ST-4 to ST-2.


Fantastic article. Beautiful shots. From what I can calculate, Lexus have the highest IC power output of all the cars this year, so 700-ish is definitely on the cards. I always thought it was an aesthetically restrained car, but definitely against the GT-R (as you pointed out) it looks much sharper.


Hope Tamiya will recreate this beauty in 1/24. Looks really good


oneisdifferent Bradders I assumed that the mounting the calipers (a chunk of metal) on the side of the wheel closest the car's centre is about doing everything to lower the polar moment of inertia. Just like mounting them low down reduces the centre of gravity. Therefore, they are in that bottom quadrant, balancing those two goals.

Probably a small effect, but this is a car that uses tiny carbon fiber canards. The article made a slight error though - brake caliper position has no effect on unsprung mass.


Twitch_6 GT500 are about as fast, when not even faster than the fastest LMP2 cars but don't come close to the speeds of a P1 machine. DTM and the Super GT will have their first race together in 2017 when everything is under the Class One structure.


Dhikaz Smiggins speedhunters_dino DTM still uses the 4 litre V8 formula but will switch to 2 litre V4 to accommodate with GT500 for 2017


_rafal speedhunters_dino the reason they actually used the M6 as a GT3 car instead of the M4, was to make the M4 race in the DTM exclusivley. Also GT3 isn't a series, it's a class which various racing series use.


David__VDB Twitch_6 absolutely not true. They're faster than the 2014 R18s. The fastest car at Fuji earlier this year would've missed the 919's pole time by just .7. It's GT300 the P2s will have to be worried about next, if they carry on their current development rate.


You site is so legend and
whenever I see your selected collection of car I must read your post. Such
company you of cars all ways totally a unique look and designs. 


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