#MIJTech

The Lexus IS F came out for the 2008 model year. That makes it 18 years old, and I still think it's one of the most important cars Lexus ever made. It's where the 2UR V8 story started. Everything that came after, the RC F, GS F, IS 500 and LC 500, traces back to this car.

So let's talk about why people still build them, in Japan and here, and how NOVEL and HighSpark fit in.

Why the IS F still matters

A compact sedan with a naturally aspirated V8. That formula is basically gone now. Toyota and Lexus spent over a decade refining the 2UR into the bulletproof engine it is today, and the IS F was the first car to get it.

And there is something to be said about wide open throttle in a naturally aspirated V8. You can't really get that from a new car anymore, at least not in a package this size.

The biggest takeaway: build it to last

At 18 years old, the IS F build conversation is different from a new car. Reliability comes first. Then you add the parts that make it feel special.

Step 1: Coils

If you've ever driven a GR86 on real roads and felt like the chassis is good but the pavement is working against you, this one's for you. The GR86 is a light, driver-focused car, and choosing GR86 coilover springs changes how it feels more than almost anything else.

So let's walk through how we'd choose between HAL's Low, Medium and High Rebound Speed springs for a GR86 on coilovers, and what to do if you're keeping the factory shocks.

First question: coilovers or factory shocks?

This decides everything.

Keeping the factory shocks? Look at the GROW Design x HALsprings sports springs for the GR86 and BRZ. They were developed specifically to work with the factory GR86 shocks, using HAL's spring design and GROW's experience with OEM damper behavior. The goal was to improve ride quality and control without sacrificing performance.

Running coilovers? Then you're choosing individual HAL metric coilover springs by size, rate and rebound speed. That's what the rest of this post is about.

The biggest

The LC 500 is a different kind of car. It's a grand tourer. People buy it for the design and that naturally aspirated V8, and most owners we talk to don't want to turn it into a track car. They want it to feel a little more special without losing what made them buy it.

So this LC 500 build guide is about subtle, Japanese, and reliable. Let's walk through it.

The biggest takeaway first

On an LC 500, every mod should pass one test: does it make the car better to live with? Coils, exhaust, brakes, then aero. No step here makes the car worse on a long drive.

Step 1: Coils

The LC 500 uses the 2UR V8 family. The HighSpark Lexus V8 kits, Standard and Premium, are listed for the Lexus V8 models. Confirm your exact year on the product page or with Tania or Kenia, since this is a newer platform than the IS F.

Why HighSpark over stock coils? HighSpark rates the spark output at 2 to 2.5 times more powerful than an OEM coil, and they stabilize the voltage coming out of the coil, so the engine runs

GROW Design is one of the brands I get most excited to talk about. Mod in Japan is the exclusive distributor for GROW Design, so this one is personal for us. If you've seen our GR86 at a show, you've seen their work.

Let's talk about who they are, what makes their aero different, and the collaborations that tell you a lot about the brand.

Who is GROW Design?

GROW Design is a Japanese aero brand focused on Toyota GR cars. Their aero is known for looking intentional rather than exaggerated. They enhance the factory lines without overdoing it, and the pieces are designed to look like they could have come from the manufacturer.

The biggest takeaway: factory plus, not over the top

A lot of aero is built to be noticed from across the parking lot. GROW goes the other way. Subtle and clean from a distance, but unmistakably motorsport up close. If you want your car to look finished, not busy or forced, that's their whole philosophy.

The GR86 lineup

For the GR86, the full lineup includes:

• Front Spoiler

If you own a Lexus IS 350, GS 350, RC 350 or another car with the 2GR V6, there's a good chance you'll deal with a 2GR misfire at some point. The 2GR is a great engine, but coils are a wear item, and they live on top of a hot engine.

So let's walk through what a coil problem looks like, how to tell it apart from other causes, and what we'd replace.

Common symptoms

• Rough or shaky idle
• Stumbling or hesitation when you get on it
• Check engine light with a misfire code
• A flashing check engine light under load
• Fuel economy dropping without a clear reason

A flashing check engine light is the one to take seriously. Back off and get it looked at soon.

The biggest takeaway: diagnose before you buy

My concern is people seeing a misfire code and immediately ordering parts. Those same symptoms can come from spark plugs, injectors, a vacuum leak, or wiring.

Here's the simple test a good shop will do. Note which cylinder is misfiring, swap that coil with one from another cylinder, and see if the misfire

The GS F is the sleeper of the F family. Four doors, a 2UR V8, and a lot of people don't notice it until it pulls away. GS F owners tend to want to keep that personality, just sharper, and that shapes how we'd plan a GS F build.

We already have a NOVEL GS F aero install guide. This post is the bigger picture: how we'd plan a whole GS F build, from coils to carbon.

The biggest takeaway first

A GS F is heavier than an RC F, and it's often a car people drive every day. So my order is coils, then exhaust and headers, then brakes and suspension together, then aero. Brakes move up the list on this car more than people expect.

Step 1: Coils

Same 2UR family as the IS F, RC F and IS 500. Coils are a wear item, and the GS F is a car that sees a lot of heat cycles. HighSpark sells their Lexus V8 coils as matched boxes of four, Standard and Premium.

Why HighSpark over stock coils? HighSpark rates the spark output at 2 to 2.5 times more powerful than an OEM coil, and they stabilize the voltage coming

One question we get about HighSpark all the time is why the coils come in boxes. Why can't I just buy one? It's a fair question, and the answer says a lot about how HighSpark ignition coils are designed.

So let's talk about HighSpark as a brand, why they push matched sets, and what the upgrade over OEM actually gets you.

Who is HighSpark?

HighSpark Ignitioncoil Japan makes performance ignition coils in Japan, and Mod in Japan imports them. HighSpark has been part of our SEMA booth more than once, including SEMA 2024 and our Central Hall booth at SEMA 2025 alongside NOVEL Racing and GROW Design.

The coils are built with premium German copper wire fused with Japanese Kyocera resin. That combination is about heat resistance and durability, because coils live on top of a hot engine all day.

What the upgrade actually gets you

Why HighSpark over stock coils? HighSpark rates the spark output at 2 to 2.5 times more powerful than an OEM coil, and they stabilize the voltage coming out of the coil,

We get this question a lot from people shopping for coilover springs. "Should I get 8KG or 10KG?" Spring rate is one of those choices where, honestly, the right answer starts with a few questions back. So let's walk through what those numbers mean, how to read a spring listing, and how we'd think about choosing.

We'll use HALsprings as the example, since we carry their metric coilover springs and the listings spell everything out.

What "8KG" actually means

A spring rate in KG is kilograms of force per millimeter. An 8KG spring takes 8 kilograms of force to compress it one millimeter. A 10KG spring takes 10.

If you're used to U.S. numbers in pounds per inch, here's the translation. One kgf/mm is roughly 56 lb/in. So:

• 8KG is roughly 448 lb/in
• 10KG is roughly 560 lb/in

So 10KG is 25% stiffer than 8KG. That's a noticeable step, not a small tweak.

How to read a HAL spring listing

Take the HAL ID65-203-8 Low Rebound spring as an example. Here's what each part means:

• ID65: 65 mm inner diameter.

The IS 500 might be one of the last chances to own a brand new, naturally aspirated Lexus V8. I've said that on our channel before and I still believe it. If you bought one, you probably already know you're going to modify it. The question is what order your IS 500 build should go in.

We've written about the IS 500 a few times already. There's our NOVEL IS 500 aero, manifold and catback post and our IS 500 exhaust buyer's guide. This post ties it all together into one roadmap, from stock to a full NOVEL car.

The biggest takeaway first

Reliability, then sound, then power, then chassis, then looks. You can absolutely shuffle that around. But that order keeps you from redoing work and keeps the car healthy while you build it.

Step 1: Coils

The IS 500 uses the 2UR-GSE V8, the same engine family as the IS F, RC F and GS F. Even on a newer car, coils are the cheapest foundation you can lay before you start adding power, especially if you plan on driving it hard.

This is also a good spot to upgrade

If you know coilover springs, you're probably going to read this and think, Steven, what are you talking about? Two springs with the exact same rate that feel different? That was my reaction too, the first time HALsprings walked us through it.

HAL is one of the brands we import from Japan, and honestly it's one of the more interesting ones to explain. So let's walk through who they are, what "rebound speed" means, and why it matters for the way you actually drive.

Who is HALsprings?

HALsprings was developed by Aki Hatano-san. They design and manufacture high performance springs for cars and motorcycles out of Saitama Prefecture in Japan, and they've been growing in a lot of directions at once.

A few things that tell you they're the real deal:

• They've developed springs for the vehicles shown in the Toyota booth at Tokyo Auto Salon.
• They worked with Super Taikyu driver Masahiro Sasaki of Rookie Racing on lowering springs for GROW Design.
• They run their own racing and development program with