The Engineering Secrets Of The 2024 Honda Civic Type R

By automotive-mag.com 16 Min Read

Front-wheel drive? So unfashionable. So gauche. But so very misunderstood. And if there’s one car that forces you to understand the power of a tractive front axle, it’s the Honda Civic Type R. That doesn’t happen by accident. In the case of the Type R, it’s a culmination of iterative and almost invisible engineering. I got to explore these secrets on a race track, and dissect every detail in my home garage.

Most hardcore nerds will know about the CTR’s separate hub carrier suspension and clever adaptive dampers, but diving deeper reveals quite a few more secrets about how Honda achieved front-drive mastery. There are invisible systems at work from the most unlikely places, evolved from the previous FK8 Type R but refined for the latest car, now called FL5. Before I dissected it in my home garage, I trooped to Buttonwillow Raceway Park to learn more about how the car behaves in the most extreme conditions.

Track Attack

I owned and tracked a 2019 Civic Type R for a year, so my impressions of the new car are largely framed by my experience with the old one. My car suffered some of the race track hardships you might have heard about–Overheating, some gearbox difficulties, and significant tire consumption–and Honda took steps to address some of those issues.

To test Honda’s progress in addressing these issues—and building a better track tool—I also have a 1:1 comparison time for both cars at Buttonwillow, driven on the same model of tires. My FK8 used a 265/35/18 Michelin Pilot Sport Cup 2 Connect, and the FL5 was equipped with the optional dealer-installed 265/30/19 Michelin Cup 2 Connect at Honda’s request. The benchmark I set with my FK8 was a 1:59.9 in +R mode with stability control turned off, or as off as it could be. I used the same settings for my lap with the FL5 and landed with a nice, clean 1:59.4.

The FL5 was different, more than I expected. It’s not the same approach to front-drive as the FK8 despite sharing much of its mechanicals and feels more tightly woven. Where my FK8 buzzed and scrambled for traction, the FL5 would manage itself with much more confidence. It would be easy to think its edges were filed down if it wasn’t for the utterly ballistic performance.

The steering effort curve was completely different from my FK8. Where the old car had strong on-center weight and nervously quick response, effort would not build with more steering input, making it difficult to read ultimate traction. The FL5 trades absolute on-center response and precision for a linear build of weight, making the car feel less alert on turn-in but easier to read the outer edges of grip. Critical information about yaw also brought the wheel to life when a slide was about to happen, but it didn’t vibrate and wriggle with road surface data as Honda suggested it would.

Then there’s the suspension, which uses the same dampers, springs, and sway bars as the FK8, which was many steps too stiff in +R mode. Across the normal range of suspension travel, like what you would use on minor bumps or light backroad driving, the dampers dispatched imperfections with a plush, Porsche-like one-and-done moment without much vertical motion. But at the very end of compression, damping force ramped up wildly, something that I suspected wasn’t entirely mechanical, and a product of the adaptive damper calibration.

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At the 2022 launch of the Type R, head engineer Hideki Kakinuma confirmed that the damper profile was highly deliberate and “extreme” to add character to the FL5’s driving experience. Considering it uses the same hardware as the FK8, the difference is shocking. The FL5’s damping stiffness, particularly at the rear axle, keeps the car on its tiptoes and makes it responsive to light mid-corner inputs. Low-speed balance is relatively pushy, where the systems (which I’ll detail later) can’t make up the difference, while medium and high-speed cornering is a stable carve that is directly adjustable with throttle input.

On Buttonwillow’s particularly bumpy surface, the stiff dampers create huge oscillations that the car couldn’t quite attenuate. Using the onboard data visualizers, which show tire load in kilonewtons, it’s evident that the car is putting high frequency, high amplitude forces into its tires. Basically, a lot of the work of handling bumps and cornering is going directly into the tires, and not being damped out by, well, the dampers. The FL5 is much more playful and communicative (in body motions rather than steering) than the FK8, but it may come at the cost ultimate performance.

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Normally, a car wouldn’t be able to handle such a strange approach. It would be peaky, nervous, and impossible to handle. And it was clearly loading the tire in extreme ways, because in about five hot laps (not back to back, each with a cooldown lap) I delaminated the center rib of the driver’s side front Cup 2. Tire pressures were at the top end of range at about 37 psi, while tire surface temperatures were at 180 degrees Fahrenheit.

The exact same thing happened with my FK8, partially a symptom of Buttonwillow, but it goes even beyond the fact that it’s a 315-horsepower hyper-hatch. There’s a big secret: Brake vectoring.

The Big Secret

Here’s the problem with brake vectoring, specifically as it pertains to the thrust of this article. It’s invisible. You can’t see it happening, and gathering the data for it would require invasive measure. It’s also something Honda doesn’t talk about much, only casually mentioning it featured on the FK8. It’s still a critical feature of the FL5 but with a bit more refinement.

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I learned just how present the system was once I started modifying my FK8. Normally, it’s invisible, but with a set of track brake pads I could monitor what it was doing thanks to the high-bite and high-volume nature of the pads. I could hear and feel brakes dragging at each corner and quickly built up a picture of what the system was doing.

On many cars, brake vectoring is understood as one of two things: A method to control traction as a pseudo-limited-slip differential, or a way to adjust cornering attitude on entry by braking an inner wheel. The FK8 and FL5 do deploy both of those methods, but takes it a few steps further by actively using the brakes at all stages of the corner.

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Agile Handling Assist, Honda’s name for its vectoring system. It’s more involved than this illustration lets on, but demonstrates the idea. Honda

For example, at turn-in, the CTR’s system will slightly brake any of the wheels (primarily outer front, inner front, inner rear) based on steering angle, yaw, and speed, helping simultaneously rotate and stabilize the car. It will adjust how much braking pressure it uses based on how much yaw is demanded through the steering. On a macro level, the car is targeting the yaw angle it thinks you want, and will compensate for understeer and oversteer. It’s clever, and a highly sophisticated bit of calibration that gives the modern Type Rs their world-beating performance. 

The FL5 is more wired up than most folks know. Each corner has a ride height sensor, and that information gets sent to the brain of the adaptive dampers many times per second. Damping forces adjust based on those sensors’ information, steering angle, and yaw, around 600 times per second. This allows engineers to actively map damping forces based on suspension travel and G forces–Practically a custom damping curve for every situation. Though the physical valving of the damper can’t be overcome, the near-instant adjustability can’t be overstated.

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Suspension data gets fed to the ABS module and Bosch ECU for the brake vectoring system, which then uses calculated tire load to determine where to send grip using the vectoring, and what sort of yaw it wants to target. Finally, the ECU also uses this data to manage torque delivery when there’s steering input, and the ABS grabs brakes to help combat wheelspin on power. It’s nowhere near a natural, raw process. It’s actually brilliant technical mastery for lap time and driving feel.

FK8 vs FL5

So, there’s plenty to dig into here with the two cars and how Honda combatted the mechanical challenge of improving upon the quite effective FK8. It didn’t make any big, splashy changes, but opted for small, iterative pieces of engineering.

To solve the FK8’s cooling woes, Honda increased the size of the FL5’s radiator, and increased the output of its water pump. Instead of the FK8’s dual electric fans, the FL5 uses a large single fan and leaves almost a third of the radiator exposed for better air extraction. A 48% larger grill opening and a functional hood vent complete the changes. In my experience modifying my FK8, the larger radiator alone doesn’t do much. It’s much more sensitive to a hood vent and extra airflow, which the FL5 focuses on.

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I can say with confidence that the FL5 largely succeeds in running cool enough for 10-20 minute track sessions. My testing with the FL5 was at about 78 degrees ambient, while my FK8 was at 81 degrees. Coolant temps remained just below 230 degrees Fahrenheit, while the calculated oil temperatures skyrocketed to 280 degrees after just two hot laps. My stock FK8 would easily max out its coolant gauge at 255 after a single hot lap, so this represents a considerable gain in cooling performance. Even if you could get it to lap for longer than 20 minutes, the tires are well past their thermal capacity, such is the energy that the CTR puts into its tires, so it balances out.

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The FL5 turbocharger. Chris Rosales

Though it isn’t strictly related to cooling, Honda also resized the turbocharger significantly. Based on PRL Motorsports’ measurements, the FL5 uses a (measured at the inducer) 44.85 mm eight-blade compressor wheel instead of the FK8’s six-bladed 46.7 mm compressor, though this number is deceiving. The FL5 turbo uses extended exducer tips to make it significantly bigger than the FK8. Effectively, the FL5 has a 59.65 mm exducer size, while the FK8 is 51 mm.

Interestingly, Honda decreased the FL5’s turbine wheel size to a 45.9 mm inducer and 40.7 mm inducer with 9 blades rather than a 47 mm inducer and 41 mm exducer with 11 blades for the FK8. Even with a slightly larger intercooler, the overall effect is a much more responsive turbo that makes more mid-range power (and more power overall) than the FK8’s relatively peaky power curve. This is where most of the FL5’s power output (315 horsepower versus 306, though this doesn’t tell the whole story) difference comes from too; the heads and camshafts are the same as the FK8. Both engines share the same 9.8:1 compression ratio. Yet the FL5 makes significantly more power under the curve, even if its peak output isn’t much more than the FK8’s. Essentially, it makes more power more of the time.

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Honda also lengthened the final drive ratio of the gearbox, while the word amongst tuners is that the new gearbox is much more durable than the FK8’s. My car needed a transmission rebuild after 80,000 miles, and regularly gave me trouble on the track with grinds, so the jury is still out on the long-term of the FL5 gearbox. Finally, a raft of small suspension and aerodynamic improvements, including a 1-inch wider front and 0.75-inch wider rear track, more rigid front uprights with massaged geometry, a new partially aluminum front subframe, revised rear suspension bushings to optimize toe-in under compression, a smoother diffuser and aero details on the front underfloor, and a fully revised steering system complete the FL5.

Mastery Through Engineering

Without a doubt, of the cars in its class, the FL5 Type R is the most technologically advanced of the group. Where the Hyundai Elantra N has a more clever differential, and the Toyota GR Corolla has a good all-wheel-drive system, the FL5 deploys the most aggressive active and passive technology. It’s Porsche-level engineering for a third of the price.

That comes with its caveats. It’s heavy on consumables; New brakes and tires will be part of the routine. It’s also so elegantly optimized that improving upon the stock car with aftermarket modifications may be tough. From my experience with the FK8, in which I found five seconds’ worth of lap time with choice mods, I think the FL5 has a much higher ceiling. Once these are modded properly, they will fly. 

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Whatever sticker shock that may come from the $45,000 price tag should be dismissed. Sure, it’s a Civic. But in philosophy, approach, and single-minded engineering excellence, it’s one of the world’s great performance cars.

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