A Method to the Madness: Setting Tire Pressures for the Race Track

Introduction

It was about two to three years ago when a friend at the track asked me the question, “what tire pressures do you run” when I first dove into the world of car setup.  The conversation went something like:

Me: I run whatever, I just like to drive FAST

My friend: Okay, but have you ever considered that you could be faster?

Me: What do you mean?  I am fast. I drive flat out.  I don’t care about my tire pressures.  Did you see that FWD drift in turn 3? I’m fast.  I don’t need to set tire pressures.

Drifting at New Jersey Motorsports Park Lightning Course

My friend: …Okay, Go out this next session and when you come into hot pits stop up at the wall and I’ll take your hot pressures for you.

(The “Ricky Bobby Effect” is slightly exaggerated here)

Note: Hot pressure = tire pressure after a full-pace session on track
Cold pressure = tire pressure in paddock or while cold, before on track

I was having issues with lockup going into turn 1 at New Jersey Motorsports Park (NJMP) Thunderbolt.  I felt as though I had more brake in the car, but the tires didn’t want to stop.  The tires felt sluggish and unresponsive to my inputs.

Turn 1: NJMP Thunderbolt

After my friend took my hot pressures once I came back into pit lane, we looked up the optimal hot pressure for the Nitto NT-01s I was running on some forums.  Based on our research, we decided to add one PSI to the tire while hot.  Miraculously, my braking ability increased, my lockups deceased, and my times decreased.

A man checking cold pressures at New York Safety Track

As outlined above, knowing one's hot and cold tire pressures can make a seasoned driver faster given different ambient conditions, but it can also improve safety for a novice track driver.

Cold pressures are typically set with a target hot pressure in mind. Because air expands when hot, we set our cold pressures low and the air will expand after a hot session, at which point we can record our hot pressure.

The hot pressure is the pressure the tire works best at. While knowing your cold pressure is important, it's your HOT pressure that will tell you if you're extracting the most grip out of your tire's contact patch.

As an instructor with the National Auto Sport Association (NASA) it's common to encounter first-time students that don't know whether they torqued their wheels, let alone set their tire pressures correctly. I have heard stories of students going on track with 60 PSI cold or 10 PSI cold and coming back with horrified, but safe, instructors.

A scared instructor

However with the right approach, you can be both fast and safe. For both approaches covered below, the assumed tools at disposal are:

1.) Car

2.) Race track

3.) A pen and paper

4.) Tire data (Google)

5.) A REPEATABLE tire pressure gauge

6.) A friend to help (optional)

Alex, TJ, and I going over tire temperature data at Watkins Glen

The First Approach (Easy but Less Optimal):

Anecdotally, tire pressure gauges are most accurate in the middle of their range. So for track days in a regular car, a 0-60 PSI gauge should do fine. This statement applies because for a street car, your hot pressures should be between 30 and 40 PSI on average.

You can purchase a tire pressure gauge from Joe's Racing, a reputable brand, on Amazon for a little over $20.

Joe's Racing tire pressure gauge

After obtaining your tire pressure gauge and going to the track, write down the ambient conditions on your paper with your pen. This should be done before each session. You should ask:

1.) Is it cloudy?

2.) Is it raining? How heavy if so? If heavy, a lot of this article isn't applicable, so stop reading now.

3.) What is the humidity level?

4.) What is the ambient temperature?

5.) What are your cold tire pressures?

Next, go to Google and search the interwebs for what people with your tires on similar cars like to set their hot pressures at for the track. It's important to get multiple opinions to get rid of the incorrect data, or noise, from your observations. Forums, Facebook, hobbyist websites, and manufacturer websites are some sources you can mull through.

Note: You can also just TALK TO PEOPLE at the track!

A review of the NT01 from Race & Track Driving

Once you know a base for your starting hot pressure, write that down, set your tire pressures at a reasonable cold pressure, and head on track. For most Civics, Integras, Miatas, and E30s with 15-inch tires, at most ambient conditions, I find 30 PSI cold to be a reasonable starting pressure.

Note: Your cold pressure must be lower than your target hot pressure. Air EXPANDS when hot!

Next, drive the car. Go out for a full session on the tires. If the car feels funny at all, try to drive around the car's character. If the car feels unsafe, bring it in. Not only will driving around your car's imperfections improve car control and driving skill, but it will allow us to reach our final goals which are:

1.) Observe what your tires feel like (very important)

2.) Get enough heat in your tires to get an accurate hot pressure (also very important)

Lawnmower life

If you've observed what your tires feel like, you should know to a certain degree what your car feels like under braking and turning. We will now use the following table to determine whether your car's tires are under-inflated, over-inflated, or just right:

Figure showing car "feel" relative to tire pressure

If, per the table, your car's tires feel under-inflated or over-inflated, adjust the pressures as necessary.  Repeat the steps of adjusting tire pressure and driving the car as necessary until you find a happy spot.

For a front-wheel drive car, when a hot pressure works well for the front of the car, I've found that the same hot pressure should be set at the rear of the car.  However, I'm close to certain that this is the right approached based on feel, but also based on data, which we will now cover in...

The Second Approach (Hard but Betterer)

For the second approach, we need one additional tool, which is:

1.) A tire pyrometer

A tire pyrometer uses a probe, inserted into the tire's tread, to measure the temperature of the tire's rubber.

Taking a reading of tire temperature (photo from Turnology)

The temperature of your tire's rubber is probably the most important measurement you can have for your tire, after your hot pressure.  This is because not only does tire temperature tell us about whether our pressures are set right, but it also tells us things like:

1.) Where the majority of the weight lies (front or rear of the car)

2.) How the spring rates or sway bars we've chosen affect tire loading

3.) Are our camber settings correct for this track?

A tire pyrometer

Some will use infrared (IR) temperature guns to read tire temperature when the car has pulled into pit lane, but this is not as accurate.

IR Temperature gun reading engine bay temperature

Part of why infrared guns are not useful for measuring tire temperature once the car has stopped and is in hot pit lane is because they only measure the temperature of the surface of the tire.  Tires cool extremely fast after a hot lap.  As a result, the surface temperature will not be representative of the tire's actual temperature at pace.

Additionally, user and machine error (distance from measuring target and surrounding brightness) can also affect the measurement.

Tire pyrometers can be found used on eBay for ~$50 if you wait for a good deal to pop up.  Mine was purchased two years ago (2017) for $50 in used condition.  It sits in the glove box of my Civic during practice sessions.  My friend Alex's was purchased this year (2019) for $60 with a carrying case.  He will be using this at upcoming events.

Alex (owner of TrashTeg) and Brian going head to head in their Honda Challenge H4 cars.

In the second approach, we do most of the same as the first, initially.

1.) Record ambient conditions

2.) Find optimal hot pressure for tire and car

3.) Set cold pressures as described above

4.) Finally, go drive the car-- observing how the car feels

Where the second approach differs starts with when we pull the car off track.  In the first approach, we may wait until the checkered flag is thrown.  After this, we may have a cooldown lap and bring the car in to record our tire pressures.  However, remember that I said that tires cool extremely fast.

So, we pull the car in a lap or two early after running it at full pace.  We come to a full stop in hot pits, and we have a friend immediately record tire temperatures-- or we do this ourselves.  If you're going to do this yourself, put your pyrometer and tire pressure gauge in your glovebox.

Recording tire pressure at Watkins Glen in a racing suit

There are three tire temperature measurements to record for each tire-- a total of 12 measurements.  We want:

1.) Inner tire temperature

2.) Middle tire temperature

3.) Outer tire temperature

I typically record my tire temperatures first, in order of driver front tire, passenger front, driver rear, and passenger rear for a clockwise rotation track.  Then, since tire pressure decreases less rapidly with time, I record tire pressures second.

There are printouts available online that make the recording process easier.  Or, you can make your own printout.  Digesting the data from a printout is much easier than a bunch of scribbles in a beat up book (which is what I do).

Photo taken from Quickcar Racing Products

As mentioned above, tire temperatures can tell you a lot about the car beyond what your pressures should be.  This is why I prefer this method.  I'll briefly go over what temperature can tell us for camber and chassis loading and get back to specifics about hot tire pressures.

Every tire has an optimal average temperature.

Average temperature should be close to that optimal temperature and is mainly driven by weight-to-tire-width ratio, spring rate, and other variables.

Camber and other alignment/chassis setup factors can affect tire temperature distribution from the outside to the inside.  Generally we want a 10-15 deg. F. distribution from inside to outside with the inside hotter than the outside.  This tells us that the camber is adequately negative for a given track and chassis setup condition.

Setting camber with a plumb bob, a stick, and some stuff and things.  Pic from LexiLaron.

However, for the sake of this article, we're looking for two things:

1.) The middle of the tire is not hotter than the outside and inside

2.) The middle of the tire is not colder than the outside and inside

Insert Civic picture here

We want to set the hot tire pressure so that the middle lies in between the outer and inner temperature.  The procedure for adjusting hot tire pressure based on a pyrometer reading is as follows:

1.) If the middle temperature is higher than inner and outer temps, the hot pressure is too high-- lower it by 1 PSI

2.) If the middle temperature is lower than inner and outer temps, the hot pressure is too low-- raise it by 1 PSI

Continue adjusting tire pressure per the procedure above until the middle temperature is in between the outer and inner tire temperatures.

Once the tire temperature distribution is satisfactory per the above requirements, we employ the feel technique which we covered in the first method.  Based off of experience with a car of the following specs, I find a range of ~5-6 PSI where I can adjust hot pressures to influence car feel:

2500 lbs Civic

B18B1 Engine (stock)

Integra brakes

Toyo RR 15/50 R205 tires

Once the car feels good, feel free to rip.  Take the data from your notes home, read up on suspension setup, make tweaks, and be faster than before (hopefully).

Peace

Thanks for reading all!  Have fun racing and driving.

#TrashTeg, The Chronicles; Part 3-- DIY Racecar Seat Back Brace

When we last left off regarding #TrashTeg, we discussed safety upgrades before an HPDE event.  In this blog post, we're going to narrow the scope a bit and talk about some specifics-- specifically regarding the seats.

Recall that the seats we used in this budget, to-be, Honda Challenge H4 race car, were found on Craigslist for an extremely cheap price due to their condition and age.  We paid ~$150 picked up ~30 minutes from home.

While the condition of the seats won't win any car shows, we don't care because we're racing the car.  However because the seats are old, their FIA certification has expired.

When doing HPDE or track days with the National Auto Sport Association (NASA) or other clubs, this may be okay as long as the car passes other safety rules.  However, wheel-to-wheel racing is a different story.  If the FIA certification is expired, the seat must be reinforced to ensure the seat back doesn't snap on impact.  To solve this problem, enter the back brace.

A seat back brace is intended to prevent excess movement of the seat forward or backward in a crash.  This ensures that the driver stays in the same spot, the harnesses do their job, and the driver is unharmed due to whiplash or other injury caused by sudden, harsh movement.  To read more about seat back braces and why they're useful, see this article by IO Port Racing.

Since our Integra was being converted from an HPDE car with a roll bar to a race car, one thing (among many) we needed to add was this seat back brace.  

The IO Port back brace is what we used, not because we're sponsored by them (I wish), but just because it's what we happened to order from them.  The kit comes with everything you'll need.  The picture below shows the contents of the kit and what purpose the components serve:

To begin installing our new brace, we first stripped the pristine fabric off of our God-knows-how-old years-old seats.

Lifting back the foam, it was easy to see where we could drill into for our new brace.

Next we began bolting things together.  In the labeled picture of the seat back brace above, you'll notice that the tube that transfers load from the seat to the cage in the event of a crash is secured to the cage with a two-piece, machined block of metal.  The top half of this block bolts to the cage and the bottom half bolts to the tube that transfers load.

We loosely bolted this onto the cage first.

Next, we grabbed our load transfer tube shown below:

And we inserted it into the bottom part of the machined block which we had loosely attached to the cage.  After doing this, we tried our best to center the bracket on the middle of the seat.

You'll notice that seat-back bracket was flat but the seat was curved.

To remedy this we needed to intervene, bending the soft aluminum with a vise and a hammer.  While in the vise, we also drilled the holes for the seat-to-bracket mounting hardware.  

Note that in the NASA Club Codes and Regulations (CCR), the mounting hardware facing the back of the car's driver must be flush with the seat, not protruding.  IO Port includes allen bolts which preclude any potential conflict with this rule and also provide for additional safety.

With the bracket bent to the profile of the seat, we centered the bracket with a whiteout marker and marked where the seat needed to be drilled.

Then, we secured the bracket to the seat using the provided hardware from IO Port.  On the side of the seat facing the racer's back, we used allen bolts with rounded heads as previously mentioned.  On the side opposite the racer's back, IO Port provided us locking nuts to use.

With the seat back brace secured to the seat and all other components loose, we finally began securing all other components which would bring us near completion.

The diagram below shows the order of final installation.  First, tighten the back brace-to-load transfer tube bolts.  Second, tighten the allen bolts securing the main block to the cage.  Third, drill a hole in the load transfer tube and insert your cotter pin:

With the back brace fully installed, we finally put the fabric back on our seat and concluded our install.  The fabric is easy to install back onto the old Corbeaus.  It has an elastic band that allows the fabric to stretch around the contours of the seat and tighten once past the edges.

Detailed photos of the installation are shown below:

On May 3rd, my friend Alex is going to New Jersey Motorsports Park with NASA Northeast to participate in Competition School for his provisional license and hopefully begin racing with the Honda Challenge H4 crew.

If you wish to attend one of our events, reach out to me in the comments section and I can get back to you ASAP!

Thanks for reading! --Track Rat

#ChelseaTheCivic, Part 4: Budget Race Car Aerodynamics

How it All Began

As I mentioned in my last post for this build, I was in a rush for my previous season.  My time was spent fighting understeer issues, improving the reliability of the chassis, and navigating financial dilemmas.  With that being said, I didn't have aero as I knew it would cost money and take up time.  Instead, I focused on affordable suspension improvements.

This Article Discusses Installing Budget, DIY Aero for Your Racecar

Using my used eBay pyrometer and some strings, I was able to dial in my alignment based on tire temperatures.  

Soon-to-be Spec E30 Driver TJ and Alex Helping me With Tire Temps

Speaking with my friend Spencer I was able to experiment with used race springs on eBay to adjust spring rates.  Spencer also turned me onto the sway bar setup I needed and my friend Alex, the owner of #TrashTeg, turned me onto deals to save me money on the sway bar setup.

Cheap, 800 lb/in, No-Name, eBay Springs

The NASA Northeast Competition School Director, Brian, is also a Honda Challenge driver, and through him I was able to determine which bushings were the most important to upgrade from rubber to spherical, rather than replacing all of them.  Of course, Chris at Kingpin sold me the product I needed on closeout when he was trying to move product and this saved me money as well.

Best Bearings in the Business

During the off-season, I had a long list of upgrades and reliability and driveability improvements I needed to make to the car.  One of them was to add a front splitter and a rear wing.

Rear Downforce

Honda Challenge H4 cars are not that fast.  The speeds are on-par with Spec E30 and Spec Miata which both use stock-spec engines and share the same suspension setups for the most part.  As a result, I knew that I didn't want a lot of drag.

People put rear wings on these FWD Hondas because it stabilizes the car in traffic (starts/restarts especially) and under braking-- two areas which are critical to laying down some fast laps and beating your competition.  The rear wings also serve to stabilize the car in high-speed corners where suspension setup is less important than in low-speed, tight corners.

Carlos Valenzuela Driving a NASA SoCal Honda Challenge H4 CRX with Aero

The rear wing needs to be balanced with a front splitter, but we'll get to that at a later point in this post.

The best wing for my car would fit the following criteria:

A.) It's cheap

B.) It's small

C.) It works

D.) It's cheap

With that being said, i turned to my most trusted source for parts that work and are cheap: eBay.

eBay is full of cheap aluminum wings that are both light and functional.  They may not be custom-made for your car, designed using CAD/CAM software, made of fancy carbon fiber, or have baller hardware, but for my purpose they would be perfect.

An eBay Wing Can be Had for Relatively Cheap

When I made it known that I was considering one, my friend, also a Honda Challenge Racer, Zephyr messaged me and told me he had an eBay wing from his old CRX race car that he would give me for free.

Zephyr's Old Race Car

The wing was perfectly sized for H4 as it's big enough to stabilize the car, but not big enough that it would considerably slow me down in the straights.  So, I mocked it up to get an idea of where it would sit.  

There were several factors I had to consider when fitting the wing.

Honda Challenge H4 rules state that the wing must be within the outline of the car's body when viewed from above, for one.  

Secondly, wings generate more downforce when placed further aft of the chassis where they have better access to clean air.  This second factor was something I gleaned from leisurely reading about race car aerodynamics.  I'm sure there are exceptions to this assumption.

A Civic with a Legal Honda Challenge H4 Wing

I used a tape measure along the sides of the trunk, a chalk marker to mark where I wanted the centerline of the wing to be, some blue painters tape to ensure I didn't have a crooked reference line for mounting the wing, and a plumb bob to ensure my wing was within the legal limits stated above.

Using Chalk Marker to Make a Reference Line for a Non-Crooked Wing

When measuring to see if the wing is within legal limits, you must use a plumb bob.  If you don't have a plumb bob, tie a nut to some kite string from the Dollar Tree.  And use that.  The point isn't to be fancy, it's to be fast.

A Picture From YouTube

Gravity is more accurate than the human eye.  The pictures below illustrate this.  It seems as though the wing is sitting just at the edge of the chassis.  In reality, the wing is moved further forward than this by a considerable amount to ensure legality.

Viewing the Wing From Above

Next, I went to Home Depot and got the cheapest hardware I could find to attach the wing to the trunk.  With each wing stand having six holes each, I knew I needed 6 x 2 = 12 bolts, 6 x 2 = 12 nuts, and washers for each nut/bolt on the outside and inside of the trunk (24 washers).

This was $20.

Home Depot Sends E-Receipts if You Provide Your Email-- a Very Useful Way to Track Build Costs

With the wing mocked up in its appropriate spot, I marked where I needed to drill and began putting holes in my crusty, 1993 Honda Civic trunk.  

Wing Stands With Galvanized Bolts and Washers Inserted

Then, I opened the trunk and cut away the reinforcement structure in the areas where the bolts protruded.  This would allow the bolts to sit properly (not crooked) in their holes and it would also allow access to someone with a wrench.

Inside of the Trunk

In the picture above, you'll notice that there are black plates underneath of the nuts and washers.  These black plates are made of steel and are intended to reinforce the wing to ensure it meets objective "C."

These black, steel plates are made from spare oil pans I had laying around my garage.  These oil pans do not sell for much used on eBay and the steel is too good to waste.  If you have a vise with an anvil head and a sledge hammer you can easily straighten the metal out where it was stamped by the OEM to make a straight piece of sheet metal.  I did something similar when mounting my MSD ignition.

Next, I knew I needed to set the angle of attack for the wing. The angle of attack, in laymen's terms, is basically how aggressive the wing sits with respect to the wind.  If it has more angle, it makes more downforce, but also more drag.  If it has less angle...well, the opposite happens.  Below is a picture of an airplane wing.  You will see that the angle of attack is measured between the wing and the air coming toward it.  Don't pay attention to any of the other terms in the diagram for now.

Angle of Attack on an Airplane Wing

My goal was to have an adjustment from close to 0 degrees to something more aggressive. While this was a loose set of criteria, I was concerned the wing would have a negative angle of attack since the stands were not made for my car.  This would make LIFT in the rear-- the opposite of what I wanted.

To measure the angle of attack, I first placed a level on the door sill for the driver-side of the car and measured the angle relative to the ground using an app on my iPhone.  There are a ton of apps out there that perform this function and if you're a DIY car person you must own one.

Next, I placed my cell phone on the wing and measured the angle of attack at the lowest setting for aggressiveness.  I got 2 degrees!  Not bad.  This meant I had plenty of adjustment if I found I needed more rear downforce at some point.  If you'd like to see more about this, just check out the video I referenced below:

Setting Angle of Attack on a Race Car Wing

With the wing fully functional, I decided I'd give it some love and paint it black as well.  I purchased four cans of budget paint from Home Depot for a total of $4 and with some 220 grit sandpaper I had laying around, I went to work.

The Wing Sprayed Black

Here's the wing installed:

Front Downforce

Balance is a virtue-- it's one of the valuable qualities for any relationship, the best diet, and of course, the fastest car.  With rear downforce only, the car may understeer in high-speed corners, though it may be more stable.  The key to a fast car isn't one that understeers, or even one that oversteers, the key to speed is balance.

Stu Chasing Zephyr at New Jersey Motorsports Park

To balance out the rear wing on the Civic, a front splitter is needed.  A front splitter increases the pressure on the front of of the car using air pressure differentials.  High pressure air goes over the car and low pressure air goes under the car.

Read More About Front Splitters Here

Using Krider Racing's writeup in Speed News, the National Auto Sport Association's magazine, I was able to amass the basic supplies needed for DIY splitter fabrication.  However, I incorporated my own twists based on my needs and my resources.

Krider Racing, of NASA SocCal, and Their Acura Integra

One twist was in how I transported my 17/32-inch-thick, 8-foot-long piece of plywood a short distance from Home Depot to my garage in a Chevy Tahoe.  This is the LoBuk, Honda Challenge H4 life:

17/32-Inch-Thick Plywood and Garden Edging

Loading an Eight-Foot-Long Piece of Plywood Into a 99 Tahoe

I then borrowed four saw horses, a dual-orbital (DA) sander, a jig saw, and a router from my friend Anthony and got to work.  I started by placing the large piece of plywood on the saw horses and taping my front bumper to the plywood.

Most People Don't Tape Bumpers to Wood But I'm a Car Person and I'm Special

Per H4 rules, the splitter cannot extend past the outline of the car when viewed from above, much like the rear wing.  So, again, we use plumb bobs to account for this factor.  The plumb bob is moved about the front of the bumper and marks are made along the perimeter so you know where to cut.

Using a Plumb Bob to Draw a Splitter Pattern

Additionally, the rear of the splitter cannot extend past where the front wheel wells begin.  Luckily, I dealt with this last year when I made an under tray out of corrugated plastic yard signs courtesy of fellow H4 Racer and friend, Ken, Owner of Ken's House Wash.  I simply marked where I needed to cut the rear of the splitter based off of the under tray I made for last year.

Undertray Made From Corrugated Plastic

Then, with my friend Alex I began cutting the splitter using the jigsaw Anthony gave me.

Me Cutting Plywood with a Jigsaw

We then used the router to round off the edges of the splitter.

Alex Attaching a Router Bit to Anthony's Router

With the splitter cut and sanded down, we mocked it up underneath of the car to see how it would look.

Splitter Under Civic

Next, we needed to mount the splitter to the car.  There are a couple of trick methods for this. For example, Special Projects Motorsports sells the Kiwi Splitter Brackets.  These brackets are quick-release and are half-aluminum, half-steel.  The steel part mounts to the frame and the aluminum part mounts to the splitter, so if you crash, the frame doesn't bend-- the aluminum brackets do.  Additionally, the quick-release is super easy to work with and most racers in Honda Challenge love them.

Kiwi Splitter Mounting Brackets

However, this car is a budget build and we don't have $198.00 to spend on splitter brackets.  That money is much better spent on suspension upgrades or reliability upgrades.  So, I used some brackets that a friend, and also fellow H4 Racer (see a trend?), Carlos gave to me.

Carlos's Two-Piece Splitter Brackets

Carlos made these brackets for the EF/CRX chassis.  The brackets are intended to mount to the frame rails where the tow hooks are originally located.  However, the EF and the EG/DC Hondas have their tow hook mounts positioned differently relative to the ground.  The EF tow hooks sit higher, and as a result I had to remove the middle section of the splitter brackets circled below:

Where I Had to Modify my Friend's Brackets

The next thing I did was add capture nuts to the brackets.  I knew I didn't want to mess around with two wrenches in a cramped space in the engine bay, so I welded some metric nuts from Home Depot that share common Honda diameters and thread pitches.  

I always try to add redundancy to the car in this manner so that if a bolt strips, breaks, or gets lost somewhere on the chassis, there is another bolt to replace it.

Capture Nuts Welded to Carlos's Splitter Brackets

I then mocked up these new brackets on the splitter, relative to the chassis, to drill holes.

Mocking up the Splitter Brackets to the Splitter

Next, I began attaching the garden trim to the splitter.  There are two trims that need to be attached.  The first is a stout, short trim that mounts to the splitter with course screws (#12 X 3/4 wood screws).  

It serves as the base for the taller garden trim which I secured to the shorter trim with nuts and bolts.  Below you will see the first stage, securing the stout, short trim to the splitter with course screws:

Short Garden Edging Secured to Plywood with Course Screws

Then I took garden edging and drilled holes at equal lengths along the its perimeter and secured it to the garden trim using SAE nuts, metal screws, and washers that you can find in any hardware aisle for about $10.  Another option is to use long rivets, but these are harder to find.

The picture below shows me sanding the fake wood grain out of the trim because wood grain only looks good on luxury cars.

Sanding the Fake Wood Grain Out of the Garden Edging

After sanding the garden trim and splitter blade, I cleaned with acetone to remove any dust or dirt which would interfere with paint adhesion.

Prepping Surfaces for Paint

And finally, I laid down a solid base coat of flat black which acts as primer (a trick I learned from an OG) and once that was dry, I laid down two coats of gloss black.  Again, I spent $4 on the budget spray paint that Home Depot sells.  Regardless of paint quality, it came out pretty good-- serving the old adage that it's all in the prep work.

Painted Splitter

Here are some pictures of the finished car with aero: