An aftermarket downpipe is an essential component when it comes to getting the most power possible from your stock turbo. With a free-flow exhaust system, you can expect higher levels of performance! It’s a vital component in moving the exhaust gases through the system as efficiently as possible. You’ll be able to outperform your competition on track day, while upgrading your exhaust note as well.For those looking to take advantage of that extra power, this Supra downpipe is essential. Made from 304 Stainless steel and hand welded in the USA, this is a top quality component. And it’s simple to install!
For those who want to get their hands on some horsepower, there are two popular modifications: upgrading the downpipe or header. What’s the difference between the two, and which one gives you more power gains? We have the answers!
So we know from the above that an automotive downpipe is an effective solution to control emissions by reducing the temperature in exhaust gas. To do that, the downpipe’s cat needs to filter gases into a large area. Without going into too much of the science involved, the catalytic converter is designed to reduce pollution by converting harmful emissions like carbon dioxide and nitrogen oxide. The honeycomb filter design inside the converter helps these gases come in contact with more areas, which makes it more efficient.A downpipe in a turbocharged car is an essential component to the exhaust system. The downpipe connects to your vehicle’s turbine housing and helps to control emissions by reducing the temperature in the exhaust gas. It also reduces back pressure on your engine so it can run more efficiently.For that ultimate exhaust flow and fast turbo spool, check out this exceptional Evo X downpipe for racing use only. This mandrel bent downpipe has a simple bolt-on installation that mounts to the stock turbo or an upgrade kit.Yes. Downpipes are one of the easiest components to install on your car. Depending on whether you’re performing the installation on a jack stand or lift, downpipe installs can take up to one hour. This obviously depends on if you know what you’re doing, following along to a tutorial, or you’re performing a whole muffler delete.
Does catless downpipe smell?
Yes, there will be smell. Many people find it disgusting and instead opt to buy the high flow, catted downpipes. You will still have your secondary cats in place, so maybe the smell will be less pronounced.
Yes. Performance catted downpipes nowadays have been shown to increase horsepower. An aftermarket downpipe with catalytic converters will add 10 to 20 horsepower on average, and that gain is noticeable anytime the turbo spools.Yes. Aftermarket downpipes certainly will make a car louder with a more aggressive exhaust note. Aftermarket ones are louder than stock because they reduce the backpressure that occurs in restrictive exhaust pipes.
The metals act as a catalyst and react with the emissions and shift harmful exhaust fumes to less dangerous pollutants. The contents inside need to be incredibly hot for the conversion to work efficiently, which is why ceramic is used. Ceramic metal heats fast and stays very hot for a long time. Without the catalytic converters, gases like nitrogen oxide, carbon monoxide and other hydrocarbons are quickly emitted into the atmosphere, causing harmful environmental air pollution.
Do catless downpipes add HP?
A common misconception is that a catless downpipe will immediately make more power. This is NOT the case for most vehicles. Modern, performance high flow catalytic converters are not a significant restriction at the power levels 99% of our cars are going to be making.
Some people believe that headers and downpipes are the same, but they’re not. A downpipe and header play similar roles for escaping emissions, but are different installations for different reasons.
What is catless downpipe?
Catless. If you want to get yourself an aftermarket downpipe, you’re going to run into two kinds: cat and catless. Catted means that it comes with a high-flow catalytic converter. Catless downpipes come without one. Catalytic converters clean exhaust gases as they pass through a catalyst.
Headers are simple bolt-on accessories used to improve an engine’s performance. Headers make it easier for the motor to push exhaust fumes out of the exhaust system. They connect to one or more cylinder heads and evacuate gas exiting out of that cylinder head through your car’s muffler.
Essentially, downpipes are for turbos only, while the similarly-tasked header is for non-turbocharged vehicles. Technically you can still use headers with a turbo, but it would have to be a custom turbo system that connects to the turbos in the exhaust after installing the header base.
Need more aftermarket downpipe or car exhaust system parts information? We are standing by to assist you in your journey. Get in touch with MAP’s experienced experts today.If you’re looking to enhance your power and torque after installing a new turbo on your MK7 GTI, then this high-flow MK7 catted downpipe upgrade does the trick brilliantly. Its simple installation, emission-ridding process, and power gains are truly second-to-none for the MK7.
Downpipes are meant to meet emissions standards and provide enough air movement for a stock vehicle’s performance requirements. Catalytic converters, a small pipe diameter (which reduces heat transfer), and restrictive angles all contribute to low flow rates on a factory downpipe that affects how well your car performs.
No worries–Installing an aftermarket downpipe doesn’t void your vehicle’s entire warranty. If you are a United States resident, then you’re protected by the Magnuson Moss Warranty act. So for downpipe installation, you may lose warranty only for your exhaust system, not the whole vehicle.
Our Subaru WRX downpipe is top-notch. It allows spent exhaust fumes to escape quickly out through to the exhaust system, increasing horsepower and torque through the entire vehicle.
Hello, I’ve been adding some mods to my 17 CTR and decided to upgrade the dp. I’m stuck between RV6 and PRL as PRL is on 5+ months back order and RV6 isn’t. The only reason I’m heavily swayed to PRL is I have plans to eventually upgrade to the p600 PRL turbo. I’m curious if the RV6 will fit fine or not as I can’t seem to find any information on that combo. If anyone can share some insight on this or has experience that would be awesome.
There is another potential reason. You might have modified your turbo so that it runs at a higher boost pressure. If you have increased the amount of boost from a stock turbo system, then the increased exhaust output might demand a smooth, larger downpipe.A downpipe is put in place because it allows the turbo aspect of the engine to be more effective. The downpipe steers gases away from the turbine, creating more uninterrupted power. When you get out on a straightaway and open up your Mercedes, or a similar vehicle, you’ll feel the difference.
Another aspect of the typical sports car exhaust system that you’ll likely notice is mandrel bending. This is where a steel rod is inserted into bent tubing, so there is no wrinkling or breaking at the bend point.
Keep in mind that the standard downpipe for sports cars is typically of excellent quality. It’s entirely your prerogative whether you’re satisfied with your exhaust materials or want to modify them further to get that extra boost.A downpipe directs the exhaust gases from your vehicle’s turbine housing into your exhaust system. The downpipe bolts right to the turbine housing. It is instrumental in moving the exhaust gases through the system as efficiently as possible.
Catalytic converters clean exhaust gases as they pass through a catalyst. This deals with the smell from the raw exhaust fumes. If you get a catless version, then the vehicle will emit a noticeable odor. That’s because the exhaust gases aren’t being cleaned before the vehicle emits them.That’s why you might want to remove the original downpipe that came with your Mercedes and replace it with an aftermarket version larger in diameter. You also might remove the catalytic converter, or another way to go is to install a high-flowing converter.
Mercedes exhausts that are standard-issue are already considered to be high-performance quality. However, you probably didn’t buy the Mercedes to be timid.
If you aspire to race your sports car, that is one of the more common reasons for replacing the downpipe. You might choose to do so simply because you are trying to get as much horsepower as possible out of your vehicle. Adding a new downpipe to older model sports cars can dramatically improve your HP.Aftermarket downpipes usually feature wider capacities, and they are less restrictive than the stock option. This increase in diameter allows for greater space for a faster turbo spin.
The average downpipe has at least one restrictive catalytic converter. These do an excellent job of cleaning exhaust gases as they are produced. The only issue is their restrictive aspect. They cause you to lose power, and likely part of the reason you’re buying a high-end car like a Mercedes is the power that comes with it.If you want to get yourself an aftermarket downpipe, you’re going to run into two kinds: cat and catless. Catted means that it comes with a high-flow catalytic converter. Catless downpipes come without one.
If you know anything about car exhaust system parts, then you might be familiar with downpipes. However, plenty of car owners have never considered this part of a vehicle. Let’s examine what a downpipe does, and why it’s such a vital aspect of your exhaust system, particularly if you own a high-end sports car.
Let’s say you get yourself a high-end, supercharged vehicle, like a Mercedes. You’re probably serious about testing its limits when you drive it. If that’s true, you might look into purchasing an aftermarket downpipe replacement.
The increased spin makes a huge difference. It decreases turbo lag and generates more spool. When you make this switch, you’re reducing intake charge and engine temperature. This will bring the increase in engine power you were craving.
Smell of Gasoline: Imagine sitting in traffic, and you’re sitting with the aroma of your own exhaust. Hey, if you like that smell, koodos to you, but from experience, it’s quite unpleasant for myself and even for the drivers around me.Mother Nature: We’re living in an era of the notion of saving the environment. With more and more Tesla’s on the road, and motor companies such as Volvo committed to go full electric, reducing carbon footprint is definitely on the consumers mind. Assuming you’re probably a motor head, this is less of a concern, but nevertheless should be mentioned.
It’s (Slightly) Louder: This one is debatable, because yes, removing the cats will make your exhaust system louder, but ever so slightly. If you care about how loud your exhaust is, I would worry more on the size of the exhaust piping and resonators within the system.It’s Illegal: For most states, there is likely an emission standard you must meet for your car to be road legal. Depending on where you live, these emissions checks could range between yearly to every few years. On top of that, you have to worry about being pulled over, because probably won’t even pass a sniff test.
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Performance. Like most aftermarket mods, you’re aiming for more power, more torque, and better throttle response. Going catless has the benefits of eliminating restrictions in your exhaust + reduces back pressure on the engine to allow for more airflow, thus more power. Eliminating the cats will also have the added benefits of reducing weight, and therefore incremental performance gains.A common question that comes up when building your aftermarket exhaust setup is the number of cats you should have in your system. A cat, short for catalytic converter is an emission control device that reduces the amount of toxic gasses and pollutants emitted out from your exhaust systems. For most OEM exhaust systems, the cats will be located in the header, and front/down pipe. Products sold by PRL Motorsports but not manufactured by PRL Motorsports are covered by and subject to warranty of the manufacturer. PRL Motorsports can help coordinate communication with the manufacturer and/or coordinate returns, exchanges or warranty claims of these products as per the terms of the manufacturer’s polices. PRL Motorsports branded turbocharger upgrades (P600) are subject to a 1-year/12,000 Mile Limited Warranty due to nature of high-power, maximum effort application and “Normal Wear & Tear.” Excess boost, improper installation, improper/lack of ECU calibration and/or use other than our intended use is subject to warranty void.
Does a downpipe increase sound?
Lower exhaust back pressure. A richer, sportier sound. Higher torque. Improved turbo response.
The PRL Motorsports front pipe upgrade promotes optimal airflow and is recommended for customers looking to push his or her 2016+ 1.5L Turbo Honda Civic even further. The front pipe is the first component in the exhaust path after the end of the emissions control system.
In the event that PRL does not ask for the damaged/defective part to be returned, we trust that the Dealer / Customer destroys or discards of this component.
Is it good to go catless?
Going catless has the benefits of eliminating restrictions in your exhaust + reduces back pressure on the engine to allow for more airflow, thus more power. Eliminating the cats will also have the added benefits of reducing weight, and therefore incremental performance gains.
An RMA number will be provided to be clearly placed on the shipping label. The Dealer or Customer will ship the component back to PRL for inspection. Warranty is limited to replacement or repair of defective parts only and does not cover labor or shipping costs, vehicle down time or any other losses on your behalf. All shipping to Warranty must be pre-paid and insured. PRL Motorsports cannot be liable for lost or damaged in-bound packages. If PRL Motorsports finds the product to be defective and within warranty period, PRL will repair, replace or issue credit to the customer at PRL’s discretion. Any repaired or replaced product will be shipped via Ground shipping to the Dealer or Customer information provided during our initial Warranty Claims process. It is up to the Dealer/Customer to provide current and accurate information. Please note that no replacement warranty parts can be shipped until the original parts are returned to PRL Motorsports for inspection. In the event a problem does occur with a PRL Motorsports component or product, please contact us at [email protected] or 724-325-6300 during business hours. We will need the following information for all Warranty Claims:Exhaust components that may become damaged over time from being coated, heat wrapped or otherwise insulated in some capacity are not covered under the PRL Motorsport’s Manufacturer Warranty. Insulating these components can cause heat to cause degradation of the material faster than would normally occur.PRL Motorsports warrants PRL branded products to the original retail purchaser that all parts/components manufactured by PRL Motorsports or sold under the PRL Motorsports brand, and directly purchased from PRL Motorsports or an Authorized PRL Motorsports Dealer honor a 12-month limited warranty from the date of purchase against manufacturing defects in the materials and craftsmanship. (Excludes other manufacturers’ components that may be part of a product’s assembly such as a turbocharger, blow-off valves, etc.) This Limited Warranty is void on all products found to have been used in racing or off-road applications, of any nature, whatsoever, and on all products that show evidence of abuse, lack of proper maintenance, improper installation, misapplication, alteration in any way whatsoever from PRL Motorsports original intent or design.
Is a catless downpipe louder?
Yes it will be louder, not too much though.
Our design utilizes 16 gauge mandrel bent 3″ tubing, CNC machined flanges and high quality, reinforced flex-section. All components are 304 stainless steel and fully back-purged on site to withstand high exhaust gas temperatures. All kits will include gaskets, stainless hardware, and components needed for a seamless installation.
Some products or components are subject to inevitable failure or wear with Normal Wear & Tear, and are not covered by our Limited Warranty. The chance or time of “normal” wear and tear failure may increase when products are operating outside of normality – i.e. high power, maximum effort, high heat, high use applications, old age, high ethanol content, high lead content, etc. PRL Motorsports reserves the right to deem products as “Normal Wear & Tear” for any reason.Please note some PRL Motorsports products are designed for maximum effort performance applications. Manufacturers can’t control the severity of off road terrain, driving habits, stress of high-performance, quality of installation, and offers no warranty of fitment or performance for a particular application. Some of our products require fabrication skills to install and all products should only be installed by a qualified fabricator or mechanic. Some items used and/or installed by PRL Motorsports may void portions of your vehicle’s factory warranty. PRL Motorsports accepts no responsibility for compliance with vehicle’s factory warranty. All Warranty Claims must be initiated before returning or sending in any parts to PRL Motorsports. Warranty Claims will NOT be accepted on parts that have been modified in any way.Limited Warranty does NOT cover minor cosmetic inconsistencies due to the overall manufacturing process (such as, but not limited to, anodizing inconsistencies, rotomolding inconsistencies, mold parting lines, etc.). Damage caused by abuse, vehicle accident, improper care or installation, negligence, or the natural breakdown of colors and/or materials over extended periods of time and usage is not covered by warranty. This includes items that were in contact with fuel, oil, and other fluids, as well as items exposed to long time heat. Some fuel system hose lines or components are subject considered to be “Wear & Tear” items and are not covered by warranty. The use of thermal coatings, heat-wrap, insulation or any coverings not intended for use by PRL Motorsports is subject to warranty void. Damage not covered under warranty may be considered for repair for a reasonable rate or a reduced price for a replacement component. For information on this, refer to the “Wear & Tear” Section
If a PRL Motorsports branded product covered by this warranty fails due to a manufacturing defect we will repair or replace the product, without charge, at our discretion. Only original, unaltered, unmodified materials and abnormal workmanship are covered by this policy.Boost creep is also undesirable from a tuning perspective. Firstly, the calibrator has little or no authority to control boost levels throughout a large part of the run. There is also a highly variable boost response depending on environmental conditions as system transitions below/above wastegate flow limit thresholds. When the wastegate’s flow limit has been reached, exhaust gas back pressure will undesirably rise (inefficient, leads to more detonation).
Now that we know the ins and outs of what a downpipe and catalytic converter are, we’ll cover the most common difference among aftermarket downpipes; catted vs catless.
This design separates the gasses in the beginning of the turbo outlet and joins them at the rear of the bell mouth section. It works well and has some of the advantages of the bell mouth and some of the advantages of the divorced wastegate designs. The main deterrent for this is the cost and complexity of adding the splitter. For most of us, keeping things as simple as possible while still making the product work well is best.With all of the exhaust systems we have tuned with on the dyno, we have seen that it is generally harder to bring boost on as quickly with these types of systems as compared to the bell mouth type systems. Also, we have had a few situations where the splitter caused problems allowing the wastegate to function properly by not allowing it to open to its full extent, or even open at all. That caused either boost spiking or no control over boost.
Is it illegal to have a Catless downpipe?
Catless anything is illegal in all 50 states after 1974 model years.
Forming pipe has almost as much design freedom as a casting with less expense and less weight. The only disadvantage lies in if it is not done properly. Poor forming can look bad and affect flow by having creases and crimped spots. You can also get the piping too thin if you try to stretch the metal too far. If done improperly you can also make the metal brittle and it will usually happen where the metal is the thinnest.
Some of the common downpipe designs include: flanges with a simple pipe, bell mouths, divorced wastegate, and split bell mouths. You also have castings and formed piping to choose from. Which one works best is also determined by quite a few different factors and how well they are designed and manufactured.
Now that we’ve covered different designs of downpipes, we come to the most glaring difference; those with catalytic converters, or “cats”, and those without. These are also referred to as catted vs catless downpipes.Pipe diameter does have an effect on flow rates but is not the major factor in most cases. 2.5″ may flow enough for 300-350 horsepower without being a restriction. 3″ is usually capable of flowing 500-600 horsepower before becoming a restriction. This is assuming that you have designed the rest of the system up to par. There are also full 3.5″ systems and those that start out at 4″ and taper down. Unless you are making over 500-600 h.p. anything over 3″ is a case of diminishing returns and in most cases has no advantage.
Is it bad to be catless?
Going catless has the benefits of eliminating restrictions in your exhaust + reduces back pressure on the engine to allow for more airflow, thus more power. Eliminating the cats will also have the added benefits of reducing weight, and therefore incremental performance gains.
A common misconception is that a catless downpipe will immediately make more power. This is NOT the case for most vehicles. Modern, performance high flow catalytic converters are not a significant restriction at the power levels 99% of our cars are going to be making. Aside from not making any additional power over a high flow catted downpipe, a catless downpipe is bad for the environment and can also be bad for you, your community, and your engine.Castings have the advantage of keeping a lot of heat in the exhaust as well as freedom with design. You can basically make it almost any shape you want. The disadvantages are more weight and cost. Cast iron pieces can weigh a ton which is a valid concern with performance in mind. The casting form that the piece is made in is also very expensive and depending on complexity can range from a couple of thousand dollars to upwards of tens of thousands of dollars.This boost creep or overboosting can exceed the factory fuel system’s capacity. This can result in dangerously-lean air-fuel ratios which can lead to engine damage. Excessive boost can also cause detonation that cannot be effectively controlled with the factory ECU’s normal response methods (reduced timing). If extreme detonation has been observed, from poor fuel quality or excessive boost, for example, one of the factory ECU’s methods for protecting the engine is to lower boost to the mechanical minimum. When the system exhibits excessive boost creep, this is no longer possible and engine damage is likely.Our customer service team often fields a certain call with a concern that “my car is running rich.” This arrival of this conclusion is come to by a smell. You might be able to tell a rich AFR via smell with a massive injector leak leading to unburnt fuel and it pouring out of the exhaust but, more often than not, the cause for this newfound smell is due to the fresh installation of a catless downpipe. Without the catalyst in place to convert those harmful gasses, they come out of the tailpipe. If you’re able to smell these gasses, it’s a safe bet they’re also going into you and your passenger’s lungs. This is not only unpleasant but can be detrimental to your health.
Since the wastegate could not function the turbo ran as if it did even not have one, and the poor turbo just ran whatever boost it could make uncontrolled. The fix was not hard, but the least amount of stuff to go wrong the better. Noone would be happy having to pay for someone to install the exhaust only to have another place diagnose the problem, remove the exhaust, repair the part, and re-install the exhaust.
Hey Mike, I’m sorry but we cannot provide information to assist in the complete removal of emissions devices. We recommend maintaining factory emissions devices if at all possible and at the very least retaining a high quality catalyst.Boost creep is defined as a condition of rising boost levels past what the predetermined level has been set at. For example, if your target boost level is 15psi, you would see the boost levels increase beyond that as RPMs increase. The short explanation for boost creep is that the wastegate is not able to flow enough air to bypass the turbocharger’s turbine housing. When the volume of air flowing through the turbine housing continues to increase, boost will also continue to increase. This is undesirable and even dangerous for several reasons.
How much HP does downpipe add?
10 to 20 horsepower Do downpipes add horsepower? Yes. Performance catted downpipes nowadays have been shown to increase horsepower. An aftermarket downpipe with catalytic converters will add 10 to 20 horsepower on average, and that gain is noticeable anytime the turbo spools.
Remember, you will only flow as well as the greatest restriction. If you have a poor cat or muffler design then it will choke the flow no matter how good the rest of the system is designed. Fortunately, straight-through mufflers and newer high flow cats flow very well. Having a cat is not only good for the environment, but we have seen very little power difference in levels in excess of over 350 horsepower. More on catalytic converters later.The only advantages to this design are cost and simplicity. The pipe does not have to be formed and the flange is simple therefore reducing cost. The labor to weld the pipe to the flange is easy and therefore less costly as well. That is the main factor that makes it desirable to the factory and why it is used on many stock exhausts. The wastegate gasses joining the turbo gasses right at the turbo outlet does create turbulence in the worst spot post turbo and reduces flow, thus not making it as desirable for performance as other designs. The spent gasses travel out of the turbine housing outlet into the downpipe. Side note: this part of the exhaust is usually called a downpipe because, you guessed it, it’s a pipe that travels downward. As turbo configurations change, the name might also (the 2015+ WRX has a low, front-mounted turbo, where a “J-pipe” is the first part of the exhaust connected to the turbine housing outlet). Whatever you call it, a downpipe is the first portion of the exhaust post turbo and is typically the most restricted portion on factory turbocharged vehicles. Upgrading this component, paired with proper tuning, is typically the best bang for your buck modification (although it does vary for platform). For all of these reasons, we always recommend using a downpipe with a high-flow or OEM catalytic converter. This will not only help meet emissions test standards, but also for performance and safety of the car. In most vehicles we support, using a catless downpipe can cause boost creep, or uncontrollable boost. This is typically something that tuning cannot fix as it is a mechanical issue that can only be resolved with a catted downpipe.This method is much closer to optimal for joining the gasses from the outlets. There is more room for them to join and if the transition is done properly it can flow very well into the main piping. It packages very well and does not have a lot of complexity, making for fewer points of failure. We have gotten the best results from this type of downpipe so far. Boost response has been the best out of the outlet designs we have tuned on and it is easy to put a wideband oxygen sensor bung into. We have also had the fewest problems with this design.
The wastegate can be internal (located inside the turbine housing next to the wheel (pictured above) or external (mounted on the header or somewhere before the turbine wheel and after the exhaust valve). Both accomplish the same function which is to bleed off excess gasses and slow the turbine wheel. This results in the slowing of the compressor wheel and prevents exceeding boost targets. This is done by actuating (opening) and allowing air through the wastegate instead of having it pass over the exhaust turbine wheel. It will then quickly close as to not bleed off too much air and cause a loss in compression in the intake tract (boost). The strategy used to control the wastegate can vary greatly between manufacturers. Now that we’ve covered the wastegate function, we can get to the exhaust downpipe.
Hey Andy, we removed some downpipes, turbo back systems, and OTS maps that support downpipes last year as part of our Greenspeed initiative. We do hope to some day offer calibration support for upgraded downpipes again but do not have a timeline on that at the moment.From the above, we know the purpose of an upgraded downpipe is to increase performance by allowing increased flow. Turbulence is one main factor. If the gasses are all stagnating and/or running into protrusions or running into each other, it creates more backpressure than a well designed system. The more laminar (smooth and straight) the gasses flow, the more the system can flow for a given pipe diameter. Steep angles and abrupt pipe diameter changes should be avoided.Back in the mid-70s this technology was required by law in the US and adopted for widespread use. This was met with pitchforks from the enthusiast community as these early versions of catalytic converters severely restricted exhaust flow. Luckily, today’s high flow catalytic converters provide enough flow to not significantly impact power output while remaining environmentally conscious.