The Guide to FK8 Honda Civic Type R Downpipe Upgrade. The FK8 Type R is the pinnacle of Honda’s Civic lineup, with a focus on track performance and efficiency. For the past 25 years, the Type R has defined the affordable FWD Japanese sports car segment, and the FK8 is arguably the best generation yet. It looks well, handles well, has a fantastic 6-speed transmission, and produces lots of turbocharged power.
The K20C1 engine that drives the FK8 Type R is a fan favourite in Honda circles since it offers all of the VTEC goodness that the K20 is known for while also incorporating a turbo. That is truly a match made in heaven. As a result, a stock FK8 Type R in the United States produces 306 horsepower and 295 lb-ft of torque. While that is sufficient for most people, some enthusiasts will undoubtedly desire more oomph. Fortunately, the FK8 platform is highly modifiable, and there are some excellent performance-enhancing mods available right now.
An improved downpipe is one of the finest performance modifications for the FK8. Downpipes are the first exhaust component after the turbo in force-induced engines, making them one of the most essential exhaust components. They are a component that can either throttle or substantially improve the performance of an engine. Because the stock Type R downpipe is of poor design, there is a lot of power to be unlocked through high-flow or catless downpipe options. In this post, we’ll discuss the advantages of upgrading your FK8’s downpipe and offer a few options.
What exactly is a downpipe?
A downpipe (DP) is the section of your exhaust that connects the turbocharger to the cat-back components. This section of the exhaust is exclusive to turbo engines. Most turbocharged cars, including the FK8’s K20C1 engine, have a catalytic converter in the downpipe. The design of the downpipe on FK8 Type-Rs is an impediment to flow due to the abrupt angular bends.
When exhaust gases enter the factory downpipe, they make a 90-degree turn into the catalytic converter, reducing flow. The stock FK8 downpipe’s exit also has a very short taper and curve, further reducing flow. Because the cat immediately restricts exhaust flow after it exits the turbo, a lot of performance is lost. A downpipe is actually nothing more than that. It connects the turbo to the front pipe, where the rest of the exhaust continues.
The downpipe is the most significant portion of a turbo engine’s exhaust because it is located immediately after the turbo. A downpipe provides the most performance increases when compared to the other post-turbo exhaust components.
Performance of the FK8 Civic Type R Downpipe
The catalytic converter (cat) in the OEM Type R downpipe aids in emission reduction. It does an excellent job at this. As a trade-off, catalytic converters are notoriously restrictive, reducing power and performance. The pressure decrease from pre-turbo to post-turbo is critical to a turbo’s ability to spool. As a result, lowering back pressure after the turbo allows for faster spool and more power. In an ideal world, no exhaust after the turbo would provide the best turbo engine performance.
However, that is not a feasible proposal for street cars. Catless and high-flow catted downpipe improvements come into play here. They aid in reducing back pressure and freeing up horsepower in the K20C1.
Civic Type R Catless Downpipe
Catless DPs are less restrictive because they remove the cat entirely from the downpipe. As a result, a catless FK8 Type R downpipe produces the most power, torque, and spool. However, catless downpipe options have a few drawbacks. A Civic Type R with catless downpipes is unlikely to pass emissions tests. They’ll also make more noise and stench than catted downpipes.
The scent and sound variations are usually manageable, so don’t let them put you off. Most people are probably most concerned about emissions. If you don’t want to deal with it, a catted downpipe is the way to go. We strongly recommend a catless Civic Type-R downpipe if you aren’t concerned about emissions or are willing to swap back to the original downpipe for emissions testing. Without a doubt, they provide the best value for money.
Having said that, new catless Type R downpipes are difficult to find these days. Due to tougher EPA restrictions, the majority of the most significant Honda aftermarket manufacturers have halted production of FK8 catless downpipes. As a result, you may have to purchase one from a used vendor.
Civic Type R Downpipe with High Flow
High-flow catted Type R DPs are frequently the more expensive option and provide slightly less performance. High-flow downpipes use the same catalytic converter as standard downpipes but have a better design that optimises exhaust gas flow. In general, high-flow downpipes produce less power than catless downpipes because exhaust gas must still pass through an additional component.
While they may not provide a significant performance boost, high-flow Civic Type R downpipes eliminate some of the hassle associated with going catless. For example, you’ll be able to pass emissions tests without having to swap out a separate downpipe every time. They’re also the ideal option for individuals who don’t want the extra exhaust drone or prominent turbo noise (though why would that be?). Like the stock downpipe, high-flow downpipes emit less odour because most of it is captured within the catalyst.
Considerations for FK8 Civic Type R Downpipe Tuning
It’s critical to realise that the majority of the power improvements from an enhanced downpipe don’t often come from the downpipe itself. Indeed, tuning is a critical component when upgrading your FK8 Type R downpipe for a variety of reasons. The first reason is that the engine’s ECU must be programmed to detect the increased airflow. You may not notice any power increase if the engine does not recognise that the downpipe has been changed to a less restrictive one.
The second reason is because installing the stock FK8 Civic Type R downpipe without a tune can cause a check engine light to illuminate. When it comes to exhaust/downpipe modifications, the FK8 Type R is a very picky vehicle. Some FK8 owners claim that without proper tuning, even catted downpipe options can cause a CEL.
While most aftermarket downpipe options include an O2 sensor bung, the factory sensor is looking for a specific reading based on the factory downpipe’s airflow figures. When you adjust the downpipe’s airflow parameters, the O2 sensor obtains a different value and generates an error. This issue can be resolved by tweaking or adding a defouler.
Pros of Honda FK8 Civic Type R Downpipe
Some advantages of installing upgraded downpipes on an FK8 Type R include:
- 15-30 horsepower (10-20 horsepower with high-flow cats)
- Gains in torque are comparable.
- faster turbo spool
- Reduced back pressure and EGTs
- Increased exhaust volume
The greatest selling point of FK8 Type R downpipe improvements is expected to be increased power. The advantages listed above apply to both catted and catless solutions. Catless downpipes, on the other hand, outperform catted DPs in every way. With catless downpipes, you may expect to gain 15-30 horsepower. Higher gains may be possible with additional mods and tuning. In any case, Type R power improvements with a catted downpipe will be 5-10whp lower than catless. Torque gains will be about equivalent to power gains.
Because of the lower back pressure, the pressure drop will also help the turbo spool faster. This decrease in pressure also contributes to reduced exhaust gas temperatures (EGTs). Individual advantages of an upgraded downpipe really add up. From a pure performance aspect, there are few upgrades in the same price range that can provide as much power.
FK8 Honda Civic Type R Downpipe Sound Upgrade
Some people have strong feelings about this one. The extra noise produced by an improved downpipe is one of the most noticeable modifications in daily drivability. An improved downpipe will almost always make your car louder because you are effectively boosting the diameter and flow rate of one of the most important exhaust components. For most enthusiasts, this is a clear advantage. However, if you drive your Type R on a daily basis and don’t want to deal with additional noise in the cabin, it might not be the best option.
A catless or high-flow downpipe will undoubtedly benefit those seeking improved sound. Almost every sound that fans desire to hear will be improved by a performance downpipe. FK8 owners who have improved their downpipe frequently say that their car generates a more perceptible bass tone within the cabin as well as louder turbo induction sounds when they press the throttle. The sound difference will be more noticeable with a catless downpipe. Catless Type R downpipes also make additional crackles and pops from the K20C1, which may be quite enjoyable.
As a general guideline, if you don’t want your Civic Type R to be louder both inside and outside the cabin, stick with a high-flow catted downpipe. A catless downpipe is the way to go if you want some extra turbo and induction noise.
Upgraded Downpipe Options for the FK8 Honda Civic Type R
Now that we’ve gotten that out of the way, let’s look at some of our favourite Civic Type R downpipe improvements. We’ll go over some catless and catted DP alternatives. It should be noted that this is by no means an exhaustive list. There are numerous businesses that manufacture aftermarket FK8 downpipes. These are just a few that we believe provide the best value for money in terms of price, quality, and performance.
1) Upgraded PRL Motorsports High Volume Downpipe
When it comes to the greatest Type R downpipes, PRL’s name frequently comes up among FK8 owners and the broader Honda tuning community. There’s an excellent explanation for it. PRL Motorsports has been committed to offering the Honda aftermarket community with high-quality parts at accessible rates since 2007. The same can be stated for their FK8 Type R high capacity catted downpipe.
One of the most notable characteristics of the PRL downpipe is the inclusion of a massive 5.0″ GESI G-Sport high-flow catalytic converter in the centre of the downpipe. Other manufacturers use a smaller diameter cat to match the diameter of the rest of the piping, which can restrict flow more than necessary. The huge cat design not only produces the highest flow rates for a catted downpipe, but it also produces less internal turbulence.
In terms of shape and construction, the PRL Type R downpipe is made entirely of 304 stainless steel and is designed to provide the least amount of resistance to gas movement. In terms of performance, the redesigned shape of the PRL downpipe is likely its most essential feature. To alleviate constraints, the wide inlet easily blends the turbine exit and wastegate gases. In addition, the exit is less sharply curved than the factory downpipe, allowing exhaust gases to flow more readily.
2) Upgraded RV6 Catless Civic Type R Downpipe
RV6 is certainly one of the most prominent and celebrated fabrication firms in the Honda community, and they continue to manufacture a superb catless FK8 downpipe after widespread discontinuance. RV6 is known for their rigorous attention to design detail, which is achieved via the use of modern CAD and laser scanning technology to assure flawless fitment. That is exactly what their catless downpipe should provide.
The RV6 catless downpipe, like the PRL Motorsports downpipe, is built completely of high-grade 304 stainless steel. As a result, the downpipe can sustain exceptionally high interior temperatures without deterioration over time. Furthermore, for improved external heat management, the RV6 downpipe retains all of the factory heat shield mounting points. The RV6 kit also includes a defouler, which prevents a CEL owing to the lack of a catalytic converter. The entire downpipe is constructed with argon back gassed TIG welds, which ensures that all connections are smooth and free of contaminants.
RV6 took considerable care in meticulously constructing a catless solution that gives the best flow dynamics and performance possible. For maximum flow characteristics, the connections between the turbo output, downpipe, and front pipe were all built utilising advanced flow analysis. The RV6 downpipe has the greatest flow figures and will produce the most horsepower of any downpipe on this list. Catless downpipes are still forbidden in CARB-compliant states. If you opt to run one, be aware that you will not be emitting any emissions.
3) FK8 Civic Type R MAPerformance Downpipe
To complete up the list, we’ll suggest another excellent high-performance catted choice. The MAPerformance crew has been providing excellent parts to the Japanese tuner market for nearly two decades and is exceptionally knowledgeable and skilled at what they do. Their catted FK8 performance downpipe is an excellent illustration of their high level of craftsmanship.
The MAPerformance downpipe, like the other FK8 downpipe alternatives on this list, is composed of 304 stainless steel for unrivalled strength and heat resistance. You may purchase the MAPerformance downpipe with ceramic coating to keep internal air temperatures low for even greater thermal dispersion. MAPerformance allows you to select which catalytic converter is included in the downpipe for more personalization. You can use the factory cat, which is more cheaper but does not produce as much power, or a GESI cat rated for 500 horsepower.
The MAPerformance catted downpipe requires simply a few tools and the included components to install. It is handcrafted and welded in Cottage Grove, Minnesota, to ensure excellent quality and craftsmanship.
Summary of FK8 Downpipe Upgrades
Upgraded downpipes are a great mod for almost any turbo engine. This is also true for the Civic Type R. Power improvements of 10-20whp are possible with a catless downpipe. High-flow catted DP’s should produce roughly 5 horsepower less. You’ll also notice faster turbo spool and a smoother power curve overall. Furthermore, catless and catted downpipes will give your Civic a slightly deeper, more aggressive sound.
Those looking for a catless downpipe will appreciate the RV6 catless downpipe’s low price, high quality, and performance. If you’re concerned about emissions, PRL also offers a catted downpipe alternative. MAPerformance, Skunk2, and a slew of other firms have some great options as well, although they are significantly more expensive.