The Lexus RC F
After driving the VR-4 for 25 years, I needed to search for a
replacement. In terms of very high performance coupes with four
seats, there are of course the American ponies and some European
models. In the end, I bought a 2015 RC F for the large
displacement engine and the loud body contours. It was a leftover
from the previous year and was available at a good price.
Test drove and bought the Shark. Named by my daughter due to the
fin on top and the side gill vents. I was originally only going
to test drive this particular car, but they offered to allow me to take
it home for the week. Well after driving it a few days, I was
completely hooked on how it felt and resolved to buy it.
May 2016 - PPF
First mod was to wrap the front of the hood, grill and side fenders
with Suntek Paint Protection Film. This particular type is
designed to use the heat of the Sun to remove slighy hazing and scratch
marks. I bought the film on Ebay (vendor "mykodesigns". I
also received my NASA plates this month (visible in images below).
Suntek PPF wrap on the hood. You can see the faint
line to the right of the hood scoop.
I was able to do a good job on most parts even though it was my first
time wrapping a car. However, the complex front end with the head
lights was a challenge, and I could only wrap it by doing it in
sections. I do have a seam right at the sharp edged running
light. I tried again in 2017, but still could not do it in one
July 2016 - First Ceramic Coat
I used the 22PLE Ceramic
coat for this first go around. It took four hours to do this job,
and the main time demand was the buffing of the paint to correct any
flaws in the finish.
August 2016 - Red Calipers
I decided to paint my brake calipers red by using high temperature paint and clear. Since they are Brembos, I obtained some high-temp decals from an Ebay vendor.
Brake Calipers painted with high-temp paint and clear
The paint has not faded in the three years since. When I added a
small touchup to repair a nick, the color was the same.
October 2016 - Dash Cam
I decided to select a dash cam that would allow me to mount it in the
grill. I didn't want a movable device cluttering up the cabin.
Dash Cam integrated into the grill.
There is a large fuse box in the front driver side corner of the engine
compartment. I found a switched feed and plugged into that for
power. 2020 Update: due to being in the weather, this
camera stopped working.
October 2016 - Embroidered Patch
After some searching, I realized that no one made an RC F patch. I worked with the online vendor The Studio. They had the best price and did not charge me an increase despite the changes I made at the last minute.
Patch that was designed and custom made. Note the
matching red DashMat that fits the Lexus RC.
January 2017 - LED interior lights
These are for example the trunk, door and interior lights. From Ebay vendor jdmautohaus.
April 2017 - Aero Kit
I like the low wide look. But instead of actually lowering the
car with after market springs, I decided to add a ground effects
kit. The kit includes a very aggresive splitter lip, the side
skirts and the rear spats. I installed this system myself without
adhesives so that it can be easily removed, cleaned, buffed, etc.
The kit was from CF500 in Boca Raton, FL.
In the year after (2018) I removed the sideskirts and
filled them with expanding foam from the bottom followed by black
rubber spray. Due to the carbon fiber material, I found them to
be a bit too flexibly, and the foam added stiffness and rigidity (see
update below for August 2019)
June 2017 - Aruba Rocks! Apparel Sponsorship
Working with the company CEO, I added decals for several photo shoots
in return for apparel (active wear, hats, etc) for the family.
April 2018 - LED lights
I installed LED bulbs into my reverse lights. Rated for 1600
Lumens from Amazon.com. Also installed projector lights in the
door as shown below.
June 2018 - Borla Exhaust
The 5 Liter V8 is one of the reasons that I selected the RC F.
However, I find its stock exhaust to be we way too quiet. From
the tests others have done, a HP increase of about 20 hp is
expected. This brings my system to 485 hp range.
Installation of the Borla took two hours of labor.
Cold start video from Facebook post
With the system installed, I would get infrequent Check Engine Lights
with the P0430 Code. A post on the Facebook group recommended the
replacement of the exhaust gaskets (which were reused from the stock
ones). This was done in Jan 2019, and I will update this page if I get
any more CELs.
Driving the car now with the paddle shifters is really much better with
the Borla. I can make the car growl and pop on downshifts. It is just
so fun and almost like playing a musical instrument.
July 2018 - Second round of ceramic coat
The ceramic coat I applied last year is only rated for one year. So I
reapplied, but this time the 22PLE VX2 PRO version. This is expected to
last several years.
August 2018 - Clearcoat of Caliper Bridge Bolts
Although the calipers themselves are nicely painted (red), the large
bolts that tie the halves of the caliper together are just bare steel
and they corrode to a dirty red color. I removed them, buffed and then
clearcoated them with high temperature clear paint.
Clearcoated (and washed) bolts on the caliper.
September 2018 - Tow Hook / RBF Tag
At work, we frequently use Red Tags (aka Remove-Before-Flight tags), and I often also see painted tow hooks used as adornment on modified cars. I thought it would be fun to combine these two into my version.
Continuing on the red-on-black theme, I decided to add a tow hook to the front.
On nice weather days, I use this NASA themed
RBF tag instead of the tow hook.
December 2018 - Lexon Rear Wing Extenders
As loud as the styling on this car is, I think the rear wing is a bit
understated. Even though it does move up and down with the speed, I
decided to add on the Lexon Wing Extenders. I think it looks much better now.
January 2019 - RR Racing Heat Shield
This intake mod was added from RR Racing and is good for 10 hp, bringing the system to 495 hp.
February 2019 - Carbon F logo
Also from RR Racing,
this replaces the large "L" on the grill with a carbon fiber "F".
The manufacturer suggests glueing this into the grill with black
silicone adhesive but I wanted to do something reversible. I also
wanted to mimic the illuminated star accessories that some Benz's
have. Since I already use the Neopixel addressable RGB LEDs for
my other hobbies, I decided to use these here also.
Preliminary installation of the F logo. The left image shows my concept
for a removable installation.
The logo is made removable by using a 1/4" plexiglass panel that is
about 6"x8". At the top I used two #6 bolts into the original
mounting holes of the OEM L logo. The thickness of this plastic
allows the bottom to be wedged into a slot in the bumper. I then
drilled small pilot holes into the back of the carbon logo and used
self tapping screws to screw it to this plexiglass panel. Long 1
1/4" self tapping screws are needed for this.
Plexi glass panel with Neopixel LEDs. The three wire cable
goes to a Flora Arduino compatible microprocessor.
The above figure shows the LEDs mounted to the plexiglass panel using
silicone adhesive. After this photo was shot and in a later
revision, I mounted the top three LEDs to the back of the panel to
increase the distance to the light diffuser. The connections
between the Flora processor and the LED string is as follows:
- The red wire connects the VBAT terminal of the Flora to the +5 terminal of the first LED
- The black wire connects Flora #6 terminal to the Data Input of the LED strip
- Finally, the white wire connects the Flora Ground terminal to the GND of the LED.
Detail of how two LEDs are chained together on the plexiglass panel.
I used 28 AWG wire-wrap wire to interconnect the LEDs. This kind
of wire is fine enough to be easy to work with the small pads.
The LEDs above and below the center of the logo oval are 4 cm from
center, and the ones to the left and right are 6 cm from center.
They are then glued down with silicone adhesive, and are thus easily
removed with a razor blade and repositioned.
Translucent white plastic bonded to the F logo with silicone adhesive. At the
top is the "Add-a-Circuit" tap that allows me to get both switched and
unswitched power from the fuse box.
Power and control lines are fed from the fuse box in the driver's side
of the engine compartment (see image below). The Flora controller
is powered from an unswitched source in the fuse box (red wire in the
middle). This uses an "Add-a-Circuit" device plugged into an
existing Low-Profile minifuse location. This has two fuse holders
built into it. The first is the fuse for the original circuit,
and the second is the fuse for the new circuit you are feeding.
For sensing when the engine starts, a switched power line (that also
powers the dashcam on my grill) is the blue wire plugged in on the
Both of these feeds need to be downregulated from 12V to 5. There
are two options for this. One is a 12V to USB power converter,
and the other is a LM7805 linear converter. The latter is small
enough to be wired inline with the wire, or on a circuit board. I
used one of each because the dashcam was an older project. Once
converted, the unswitched power is connected to the battery terminals
of the Flora controller but the switched power needs to have a 2:1
voltage divider to to ensure that we do not exceed 3.3V on the logic
input for the Flora. I used a pair of 2.3k resistors for that.
The inside of the fuse box showing how I tapped in for power.
Red wire is unswitched 12V and blue is switched 12V.
Since each LED is RGB and completely addressable, any pattern is
possible. When the car is not running a red 'heart-beat' pattern
runs. The brightness is ramped up fast/slow as needed to
accentuate the effect. As soon as the car start event is
detected, a white animation runs that spins a few turns while the car
starts up. It then stays on solid white while the car runs.
See here for a video.
The heart-beat pattern runs for three hours after the car is shut off
and draws about 40mA. Once the LEDs are shut off, the standby
current is only 15mA. In practice this effect is really best seen
at night as the white diffuser is very bright during the day.
May 2019 - Hood Scoop Tests
As you can see above, the RC F has several functional air scoops
(unlike the GR Supra, which has over a dozen fake ones). The hood
scoop in particular has an internal cover that looks like a rain
guard. From the start, it felt to me that this guard would
obstruct air flow and I removed it by popping out the trim clips.
View from under the hood with the rain guard covering the hood scoop.
You can see the small opening in the top right for air flow.
This is with the rain guard swung away, revealing the exterior scoop.
In May 2019, there was some debate on the Facebook group if this
removal was a good idea or not. The counterargument was that the
small opening would create a Venturi, which would actually help draw
air out of the engine bay. I decided to run a test with a remote
temperature sensor to get some data on this question.
I did five runs on a sunny spring morning on the East Coast US with the
hood temperature sensor mounted just aft of the scoop opening (see
image above). The readout was then placed at the base of the
driver's side A-pillar so I could observe the temperature as I was
running. In addition to this hood sensor, I also used the
built-in ambient air sensor of the car, and a separate hand held
After letting all three sensors settle overnight in my garage, I first
took baseline readings on all three. I then drove for half hour
to the test road to get all coolant and oil temps to the normal
range. I then did a run with my standard configuration (no
cover), then with the hood scoop taped shut (so non-functional scoop),
and then next the stock configuration. I finally finished with
two runs of the no cover configuration to see if conditions were
consistent. All runs were done in S+ mode (so no Atkinson cycle),
and at a sustained speed of 70 mph. The data is summarized below.
All readings in F
|Ambient (car sensor)
|Under Hood (wired sensor)
|Ambient (hand held)
|Prior to run
|Scoop taped shut
|No cover (60 mph)
As you can see above, and to my surprise, the best reading was with the
scoop taped shut. Now in full disclosure, there was a small
opening as the tape pulled away from my paint (ceramic coated and
waxed, so very slick). While driving, I could see the tape
bulging out and up, indicating either lift from the air flow above, or
positive pressure below. By the time I had stopped, there was a
small opening pealed up.
But the second surprise is how much worse the no-cover configuration
was. It was a consistent 53F rise with the 70 mph runs and
slightly worse at the lower 60mph speed run. Presumably , in the
case of the latter, the lower speed meant lower air flow.
In the light of this, I have put back my rain cover. It is
possible that at even higher speeds, the stock configuration would win
out over the no-scoop configuration. This result reminds me of the
RR-Racing find that the stock intake is already very good. The
only improvement they could justify was the intake diverter.
Lexus must have done testing on the design already. As a final
note, I have always liked seeing the blue intake runners when the hood
is closed. I guess I will now have to unfortunately do without
August 2019 - Artisan Spirits Side Skirts
A short time after purchasing this car I started to look at aero
enhancement kits. One that stood out was from Artisan Spirits,
especially the side skirt. All the others seem to have a horizontal
shelf design (like the ones I installed above) which I felt break up
the lines of the car. However, the AS ones had to be shipped from Japan
and were not painted. So I decided to settle instead on the ones from
In 2019 a member of the Facebook page on the RC F decided to part out
his car. He had a set of AS side skirts and they had been painted gloss
black and then covered with carbon fiber wrap. Since they were
protected this way, I reasoned they would be in good condition and
Image from Vivid Racing site of the AS Side Skirt. These continue the curves and
creases of the body and I like the way they flare out on the bottom.
I wrote AS in Japan and other distrubutors but none would send me
installation instructions (the seller had long discarded what he had).
Once I removed my old ones and test fitted these I decided to make some
brackets to be able to freely position the skirts without drilling new
holes into the car. The brackets, which install into the rear wheel
well, also allow me to lower their position a little and rotate the
bottom edge outwards. These brackets are made from aluminum and then
painted gloss black. Since all the forces will be in the plane of the
sheet (which is clamped between the sideskirt and the car), bending of
the metal sheet will not be an issue.
Aluminum panels made to allow custom fit of the side skirts
I am very pleased with the appearance of the car at this point. Hard to
see in the pictures that they make much of a difference, but in person
the whole package looks great. The design and profile of this side
skirt is quite different than the one from CF500. For one thing, the
bottom edge is painted and faces the ground. So to protect this
surface, I wrapped it with clear Suntek film.
Sketch comparing the profile of the AS and the CF500 side skirts.
The figure above shows a sketch of how the designs of the two side
skirts compare. On the right is the old one from CF500. Due
to its thin Carbon Fiber design, they were very floppy when pushed in
the direction of the red arrow. I filled them with expanding foam
and painted the bottom with black rubber paint to improve them.
The AS ones on the left do not have this issue as it is like pushing on
a box beam. The green area is the Suntek film.
Side Skirts installed onto the car.
November 2019 - Helper Springs for the Rear Wing
Since this Summer, I started noticing that my rear wing was not working
properly. It would rise very slowly and sometimes not go down
when I stopped the car. Cycling it while parked would be very
unreliable. I decided to remove the extenders to return the car
for service at the dealer. Once I had the extenders and the wing
completely removed, it worked just fine, and I theorized it may be due
to the weight of the assembly. With only the stock wing back on,
the mechanism worked a little better.
The dealer found that the control unit had gone bad and they replaced
it. I was a little skeptical at that assessment. It worked
somewhat better after the service, but it still continued to rise very
slowly and you could hear the motor really slow down while it did
it. I guess I could have just used the system that way until it
would perhaps fail and then get a new motor, but I also wanted to put
my extenders back on. I found that simply placing the extenders
on top of the wing was enough weight to cause the wing to no longer
rise and work. The motor was simply too weak to push the weight
up, and I had to either forgo the extenders or think of a fix.
One requirement of any mod I would make here is to have it be
reversible. After some consideration, I hit on the idea of adding
a pair of springs to compensate for the weight of the assembly.
The stock wing (non carbon) is about 6.5 lbs, and the extender kit
(four bolts, and two caps) were 14 oz. I went to the hardware
store and after lots of brain storming and tests came up with the idea
Diagram of the helper spring installation. The view is toward the passenger tail light
from inside the trunk. Note that I taped a flag onto the shaft to show its
two different positions.
The wing is operated via a drive shaft that rotates about 45 degrees
(when facing forward, it pitches up). The mod consists of a lever
that clamps onto the drive shaft, and a spring then pulls on the lever
to form the assist mechanism. Based on the capacity of the spring
(about one pound), and the length of the lever, I would estimate the
torque assistance to be about 4 to 5 inch-lbs.
Parts used for the assembly. Obtained at Home Depot.
I have had this assembly in place for the past few weeks and it appears
to work extremely well. The rise and fall time is now well
matched and it the mechanism works smoothly and silently.
This project reminds me of an idea I had earlier in the year where I
was wondering about using a linear actuator to raise the rear wing in a
manner similar to the LFA. I would need two of them on each end
of the wing. It turns out that there are four holes in the top
deck of the trunk that these actuator rods could go through, and it
could be a mod that could be added and removed without exterior
modifications. I purchased one actuator as a test, but did not
pursue the project any further.
Linear actuator commonly available on Ebay. They can support many
hundreds of pounds in compression, but the bending load is unknown.
February 2020 - A/V Jack Connection
I did some investigating on how to feed an audio/video signal into the
main dash display. It turns out that there are several standards
for the "4-pole" A/V plug in the armrest compartment as the following
diagram from Rocket_Scientist shows.
Two possible pinouts for the A/V plug. The RC F uses the BOTTOM format.
It turns out that I have cables from both types in my spare parts bins,
and I used the top type initially. The video was very distorted
and there was a lot of hum. I then dug up the second one and it
worked fine. Using my meter, I 'buzzed' out the connections and
that confirms the match to the above two diagrams.
In addition to different pinouts, the two cables have different looking
4-pole plugs. The compatible one is on the BOTTOM.
To mirror my iPhone, these are the components I used.
It is possible to mirror the phone on the dash display. To do
this, I used the above components. The top is a Lightning to HDMI
converter ($15), and the bottom is an HDMI to A/V converter from Ebay
Phone mirrored on the dash.
In order for the video to be displayed on the dash, the A/V needs to be
selected (under Media), and the footbrake (E-brake) needs to be pushed
down at least partially to activate the sensor switch. In the
future, I may look into a camera that gives me a view of the right edge
of the car to better avoid curbs when I turn (some also add a camera to
the front to avoid hitting th lip). I could then select the
camera with one pushbutton ("Media" button on dash), and then another
switch that temporarily closes the E-brake button. This would not
have any effect on braking, but it would produce an annoying beeping
March 2020 - trunk spoiler
After adding the rear wing extenders, I have always felt the very back
end missed something. So I have been looking for somthing to
finish that area. I like this one from Nia, but the price ($550)
was a bit higher than I wanted to pay. During the COVID-19
pandemic we were staying home a lot and it is during that time that I
found this inexpensive ($55) trunk spoiler from Dealer Choice Parts.
This sequence shows 1) with no trunk lip, 2) with, 3) spoiler extended
As you can see in the above sequence, the new spoiler lip is wide
enough that it may interfere with the stock wing if the extenders were
not present. Update: this spoiler lip is wide enough that it does
interfere with the stock wing (from FB exchange).
April 2020 - Red Stripe
The red pin stripe was added by using 1/4" vinyl tape.
June 2020 - Phone Holder
A problem that many have is how to hold the phone for use while
driving. I need it mainly for running nav apps such as Waze.
I had the following requirements:
Hold the phone as high up as possible without obstructing view of the road.
I need to be able to interact with the screen with one hand without the phone moving around.
Have the phone in portrait mode to best run nav apps.
Do not obstruct vents.
A plus is to have no screws or holes drilled into the interior and it should be easily reversed or removed.
After some positioning, I realize that making a simple bracket out of
sheet aluminum that mounts by the clock in the dash was the best
The bracket simply slides into the gap above the clock.
It is super easy to drop the phone in to the holder.
October 2020 - Matching Rear Spats
When I received my Artisan Spirits side skirts, they did not include
the rear spats (part behind the rear wheel). I tried buying only
those small parts from Artisan, but received no reply. After some
routine checking on Ebay for RC F parts, I found that someone had
started making replicas (seller: carbon_aero), and that the rear spats
were available separately. I paid about $300 for the pair.
Although the carbon fiber weave is really nice, it does not match the
gloss black. I will use them that way for now.
Installation was not trouble free, but neither were the authentic side
skirts. I am super happy with the way they round out the
sides. I used 1/4-20 threaded rods and stainless nuts to mount
them and that allows them to be adjusted.
These cover the sideview mirrors and are made from carbon fiber and
were bought from another member of the RC F Facebook group. I am
not a big carbon fiber fan, but since the car is black, they blend in
At this time I also placed the 'F' badge on the side skirts.
These were inexpensive and from Ebay. The bottoms are concave and
I was concerned about the poor contact with the double sided
adhesive. To address this I filled them in with hot glue.
They are a good match to the authentic emblem.
November 2020 - Mirror Caps
April 2021 - High performance air filter
K&N air filter
During the install of the K&N filter, I found that the air box has
a carbon filter that covers half of the air filter (odd that it is just
half), but the thinking is that it does not impede performance.
Typical improvement with the K&N installed is small, perhaps 2%,
but due to the large engine it means a gain of about 10hp. With
the Borla, the heat shield, and this, it should put me at the 500hp
mark at the crank.
May 2021 - Stop/Start Button
A cosmetic enhancement from bonoboproducts.com is a machined aluminum
red Stop/Start Button. It is a good match to my red interior.
August 2022 - Mirror Power Tap
View of connector above the rear view mirror with the cover removed
In the 10-pin connector above
the mirror, there is present: unswitched
power (top left, above the blue), switched power (blue), and ground
(purple wire to
the right of the blue wire). I found that using 24 gauge pins
from a D connector worked well to tap this without splicing. I
simply attach wires to the pins and insulate them with some
heatshrink. This is then inserted into the back of the connector and can be done without demating it.
Two-wire cable with pins inserted into the back of the connector.
This taps the Switched Power.
August 2022 - Dashcam
I installed a AZDOME "4k"dash cam to the above power tap. One
requirement for me was no display. This unit was quite
inexpensive at less than $100 and had a front and back camera.
I had a 12V to 5V switching converter available that fit into the wire cover.
5V converter installed and everything is very clean with the cover installed.
Sample image of a car 20 feet away.
Full view at top (reduced in size to show FOV)
and cropped native resolution.
June 2023 - F-Wing
RR Racing developed a spoiler enhancement
that really captured my attention as it closely resembles the configuration of the Track Edition
but that maintains the function of the active aero. It not only
sets the spoiler up higher (somewhat cleaner air), but also adds side
plates that I think act similar to winglets
When I first received the kit, I was a bit concerned about the
additional weight on the stock spoiler mechanism. At this point,
my spring mod
had been in place for four
years, and it has worked flawlessly ever since. Before their
installation, the active spoiler worked eratically. I temporarily
taped the new support beams onto the back edge of the spoiler and saw
that it was only able to very slowly deploy upwards. So the first
thing I did was to increase the pull force of the springs by shortening
them by 2/3. The spring has about 30 turns, and I removed
10. This increased the pull force so that actuation time was more
even between rise and drop.
I then installed the kit and I think it looks really nice with
it. Fortunately, I have a black car, and it all blends in with
the existing look.
Spoiler enhancement attached.
Some tips /observations for the assembly:
- Guard against dropping a bolt or socket into the lid of the
trunk. This is easy to do as you are working through holes in the
trunk wall. If a socket gets hung up on the edge of the hole and
pops off your driver, or if you drop a bolt, you are in for a world of
problems. That occurred to me as I dropped one of the spoiler
bolts into the trunk lid wall but was fortunately able to retrieve it
after a harrowing hour of work. So to prevent this from happening
again, I put a magnet into the socket to hold the bolt and taped the
socket to the extension so it would not pop off. I also feel the
best way to remove the bolts is to do so with the trunk almost closed
so that if it drops, it will fall into your hand.
- As you can see below, the cover plates did not exactly line up with
the mechanism. This caused the plate not to sit flat on the
actuator. I initially did not think this would be a problem, but
after I mounted everything, there was enough of a twist between the two
posts that the mechanism would not smoothly rise and fall. I
addressed this by using a round file to open up the bottom hole.
By the time you read this, RR may have fixed this issue.
- If you have a stock spoiler (vs an aftermarket long tail), be sure to
remove the rubber bumpers on the bottom. The best time to do this
is once the spoiler is completely removed and you can flip it upside
down. It took me a long time scraping the residue with a plastic
card and alcohol. Just take your time and be thorough so that the
plates have a good place to adher to. I stuck the unneeded
bumpers to the underside of the metal trunk lid so that they don't get
lost and I see them if I decide to undo this mod in the future.
- At this point it is a good idea to replace the stock spoiler bolts
with M6x1 fasteners hex head fasteners. Previously (when adding
the Lexon extenders
), I striped the heads on several of the stock bolts and had to drill them out to remove them. I believe they were the JIS standard
and easy to strip. I have heard of others doing this
when replacing the spoiler mount.
- It is possible to swap the end plates
. I think it actually looks better that way, but I decided to follow the way the Track Edition is configured.
The true test of a proper install is to see if the mechanism is able to
work at 55mph when the air is pushing down on it. Running a test
shows that there is enough asist in the spring to allow the spoiler to
work and it rises nicely in my rear view mirror. Fortunately, it
is high up enough to not block my vision out the back, and it looks
cool to see the entire curve of the spoiler in my mirror. Rafi
from RR Racing let me know that this mod has been tested to 170mph
The cover plate over the mechanism did not have the
correct hole spacing and it did not sit flat. Both plates had
this issue and this introduced a twist into the spoiler.