How to connect headers to exhaust pipe

All the stuff you were afraid to ask — but really want to know. So performance fans want to know: if I modify my exhaust system, how does each component affect the sound, performance and mileage of my vehicle? What follows is a cursory review of what these parts do in the scheme of things. To begin here are the key components:. Exhaust headers most commonly are a series of individual tubes that attach to a flange that bolts to the cylinder head replacing the more restrictive to air flow exhaust manifold generally installed by the original vehicle manufacturer.

The tubes flow into a collector that merges the tubes into one large tube and attaches to the rest of the exhaust system An aftermarket exhaust header can come in several forms; shorty, mid-length and long tube.

how to connect headers to exhaust pipe

Long tube headers generate the biggest horsepower increase of the bunch, shorty and mid-length headers delivering minimal power gains. Installing any header can cause an issue with regards to emissions and may not be legal in your location.

Getting the correct primary tubing size header for your application is key to maximum power gains so asking an expert when you purchase is important. Introduced inthis device was used to affect emissions output. It is illegal to remove the cat from your exhaust or replace the original cat installed on your vehicle if it has less than 80, miles.

Cats can be highly restrictive so many performance enthusiasts remove the cats, which render these vehicles out of emissions compliance.

Hooker 42107HKR Long Tube Headers to Exhuast Kit Adapter Pipe

With older cars, the tubing that connects the exhaust manifold to the main section of exhaust that flows under the vehicle are called a Downpipe since is goes down under the vehicle.

With new vehicles, a downpipe is the tube that connects the turbo exhaust tube to the main body of the exhaust that runs under the vehicle. Some manufacturers have generated significant gains from modification of the Downpipe design. The section of tubing that runs under the vehicle — either single exhaust or dual, is generally referred to as the Mid-pipe. Performance manufacturers have developed a number of Mid-pipe modifications that enhance both the power and sound generated by the entire exhaust system.

In contrast, an H-Pipe features a connector tube that runs perpendicular to the mid-pipe and generates a lower tone. Both X and H Pipes are recommended for improved performance by exhaust experts by equalizing the pressure in the exhaust, side to side, which helps exhaust flow. These components do exactly what their names imply. A Cat Back system bolts to the tubing that exits the catalytic converter and usually includes mufflers and some form of outlet tube.

In many cases, the exhaust tip is attached to the end of the cat-back system. Axle Back systems bolt to the mid-pipe tubing as it passes over the rear axle of the vehicle. Both Cat Back and Axle back systems may attach to a natural break in the system or could require cutting the tubing as some point.

How To Wrap Exhaust Headers

In most cases, these kits use a clamp to fasten then in place but can also be welded if the customer requests. You might mention that many axle back systems have the mufflers in the section of the exhaust system back of the axle. There are different forms of stainless steel used today with aftermarket exhaust systems. Stainless is the only way to go with aftermarket exhausts. While some high priced exhaust systems incorporate SS, a higher grade, it is more brittle due to the higher chromium content.

It can be polished to a mirror finish but unless you have a show car, no one will ever see it. More brittle materials equate to cracking over time. Legato uses SS for increased durability and finish off our kits with SS highly polished exhaust tips because that is the part that you do see. Using SS for the main body of the exhaust is added cost with additional problems that can occur long term.Our fearless editor, Ryan Manson, is a busy guy, so when he began building a Ford pickup and needed a long list of parts and wanted them fast Manson turned to America's oldest speed shop, Speedway Motors.

For motorvation a Speedway exclusive hp small-block Ford crate engine machined and assembled at BluePrint Engines was chosen. With the engine and transmission in place, the next step was to install an exhaust system. Another call to Speedway and the parts were on the way. Over the years there have been hours and hours of exhaust system testing and the results are the same—headers make more horsepower than standard factory cast-iron exhaust manifolds.

Just as with factory manifolds there are differences in headers—in most cases Try-Y headers produce more bottom-end power, four tubes are better on the top end, and primary pipe and collector pipe size are best tailored to the displacement and rpm range of the engine. While headers offer advantages in performance, they can be difficult to fit into a tight engine compartment—a fact that led to the development of tight-tuck headers.

This design has short primary tubes and collectors that are close to the block, allowing them to fit where long-tube headers can't. As you might guess, these abbreviated designs don't offer the same advantages as long-tube headers, however they are an improvement over stock manifolds—think of them being in-between the two in terms of performance. A decision that has to be made when selecting headers is the material they are made from—mild steel, ceramic-coated mild steel, or stainless steel.

Mild steel is the least expensive option but in time rust will be an issue. The very popular metallic ceramic coatings offer a variety of advantages; not only does it look good but it helps contain heat inside the pipes, which increases the speed of the exhaust gases and in turn increases performance.

Of course those attributes come with a price increase over comparable bare mild steel headers. Another popular choice for header construction is stainless steel.

It is said that the thermal characteristics of stainless steel help to retain heat in the pipes like coatings and quality stainless headers will never rust and it can be polished to near chrome brilliance. When designing an exhaust system pipe size is always a concern, and it's not uncommon for builders to think bigger is always better. The truth is pipes that are too big for the engine will allow the exhaust gases to cool and slow down, which kills low-end torque.

The trick is to pick a pipe diameter that maintains exhaust gas velocity while minimizing backpressure. Another consideration when building pipes is the type of bends. Pressure bends, or crush bends, are commonly done in muffler shops because they're quick and easy and virtually all shops have the equipment to make them.

The problem is they reduce the diameter of the pipe whenever the smallest bend is made. That restriction in flow kills off any advantage the larger-diameter pipe offered. To maintain flow the best option to weave exhaust pipes around components is the use of mandrel bends. Mandrel bends are smooth and maintain a continuous diameter so exhaust flow is not impeded.Forced induction, through the use of a turbocharger or a supercharger, forces additional air to the intake charge This forced air is referred to as boost.

This creates higher cylinder pressure, allowing the engine to produce more power. By contrast, a naturally aspirated engine uses available ambient air to enter the engine, mix with fuel, and ignite in the combustion chamber.

The purpose of either system is to pack more air into the engine than is available under normal atmospheric pressure. Atmospheric pressure is More than likely, power increases by around 40 percent. One of the ways to help maximize efficiency is to tailor the exhaust system for maximum exhaust gas scavenging. A supercharger pressurizes the intake system and flows more fuel into the combustion chamber. If your engine is fitted with a supercharger, you need to select a compatible exhaust system.

A turbocharger uses exhaust gases to pressurize the intake system. Turbos generate heat so heat management is a top priority because excessive heat robs an engine of power. Most supercharger kits, such as the one shown here, include everything required for the installation. Depending on the type of supercharger and the specific manufacturer, kits may include in addition to the supercharger itself an intercooler, programmer for EFI applicationselectric fuel pump, regulator, special air intake, and serpentine-belt idler pulley.

Photo Courtesy Edelbrock. There are three types of superchargers to consider: twin-screw, Roots, and centrifugal. The mated pair of high-precision matched rotors progressively compresses the air between the screws as they spin in opposing directions. A tight clearance between the screws compresses the air as it is drawn from one end of the screws to the other end.

The Roots-type supercharger has opposing male rotor lobes inside a housing. As the lobes rotate, air is pushed between the outside of the lobes and the housing case, blowing additional air into the intake system.

Twin-screw superchargers are said to produce less heat than the Roots type for a cooler air charge, but with intercooler aid this may be a moot point.It could be just how you like something to look or function, or just an extra step you take to save yourself headaches in the future.

It seems either they crack at the welds or they just fit poorly and leave much to be desired when fitting the rest of the exhaust. Both of these tend to either leak right out of the gate or after a short period of time. Forget even trying to run an old used header! I decided to show my solution that has solved my header leak issues over the years. I decided to build the exhaust from the headers and get it down under the truck where they could easily build the rest of the system back on the lift.

These headers had a 3 bolt flange and I started by using a reciprocating saw to cut the flange off. I had to make the cut extremely close to the flange itself as the collectors for the headers were only a few inches from the flange and I needed space to slip the end of the flex joint into the header. Above are the flex joints that I like to use. They have a stainless mesh flex section that gives you a lot of flex for engine movement.

For strength I decided to slip the flex joint inside the header. If you have an exhaust spreader handy you can flare the end of the header, but in my case I was working late at night and mine seems to have walked off!

I decided to keep working and did an ultra basic method of flaring the metal with a crescent or adjustable wrench. I slowly worked my way around the edge until I had a large enough flare I could slip the flex joint into. Once I had the ends flared out I slipped the flex joint I had to use a rubber mallet as the slip joint should be a tight fit into the header and used a hammer to tap the metal tight all the way around the new flex joint. With everything sitting how I wanted I put a single tack weld to join the two pieces.

I then trued the joint up again it will tend to move a little from the heat of the first weld and put a second tack weld degrees from the first. With the flex joints secured I could work my around the union and weld it up fully. With a MIG you can burn right through the coating no problem. With the flex joints welded I bolted the headers back on and used TIG wire to make templates of how I needed the short pieces of pipe to come out of each flex joint to get the exhaust down next to the frame and under the cab.

how to connect headers to exhaust pipe

I had the local shop bend me up two pipes to match and I fit and positioned them at the correct angle. I pulled them back off and fully welded those to the flex joints.

The result is a set of headers and down pipe custom made for Pilehouse that will allow for a full exhaust to be fabricated. The last step was to spray the header and dow pipe with Eastwood Hi-Temp black exhaust coating. I really dig the subdued satin black look and it almost sounds too good to put mufflers on!

The main point to remember with this fix is: Will it work for my application? It is not a fixall for every situation,merely a very good suggestion. Thank you. Nice write up and a great idea. Not only are they in the write up but also in the comments. Yep, very good idea. I had the same thought about 5 years ago. I noticed the se flex joints on mostly front wheel drive cars and normally when the exhaust side is in front and the pipe has to cross under the motor to reach the back of the car.

After about the 4th gasket replacement on that header, I had the same thought. So I did the same thing. I welded the flex pipe section to the back side of the collector flange. I didnt want to alter the header itself. This has lasted going on 2 years now and rock solid no leak fix.Display Options.

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Inlet, 3 in. Outlet, 2 in. Length, Each. Loading Today Estimated International Date Loading Today. Inlet, 4 in. Outlet, 4 in. Exhaust Pipe Reducer, 3 in. Inside Diameter to 2. Inside Diameter, 6 in. Long, Each. Exhaust Collector Reducer, Steel, Natural, 3. Inlet, 2. Outlet, 4. Exhaust Pipe Adapter, Steel, Aluminized, 2. OD Inlet, 3. OD Outlet, 6. Outlet, 2. Inlet, 3. Exhaust Pipe Reducer, 4 in. ID To 3 in. ID, Length 6 in. Outside Diameter to 2.

Pie Cuts, 3. Diameter, Stainless Steel, Set of 6. ID To 2. Exhaust Adapter, Coupler, 3.In this chapter, I discuss the pipe that routes exhaust gases from the headers to the termination of the exhaust path, as well as pipe sizing, materials, bending methods, pipe clamping, and pipe support.

To select exhaust pipe for a given application, first consider your budget. Expense factors include materials, quantity of pipe single versus dual systemthe application of a specialty coating, and pipe-bending labor.

Stainless steel is more expensive than mild steel. The advantages of using stainless steel are longer life, in terms of corrosion resistance, and superior heat transfer. Pipes made of mild steel are available as bare steel, but are also commonly offered with corrosionresistant aluminized or galvanized surface treatments. If your budget allows, stainless steel is preferred, especially from standpoints of longevity and long-term appearance.

In terms of fitment to a vehicle, you can cobble a system together by purchasing a selection of pipe shapes straight sections, pre-bent degree and degree sections, etc. Pipe-to-pipe sections must be either welded or clamped together.

Another option is to purchase a pre-formed kit that is already shaped to fit your specific vehicle. Many manufacturers offer complete systems for popular vehicles that include pipe and mufflers that generally require only assembly and installation.

how to connect headers to exhaust pipe

Yet another option is to have your entire exhaust pipe system custom-bent for your specific application. The custom approach is often required for unique applications, such as custom street rods, where no pre-designed system may be available. The choice of your pipe system is based on both cost and how much, if any, of the work you prefer to do on your own.

Your selection of pipe diameter should be based on engine size and existing or planned horsepower level. Typically, a performance-oriented V-8 engine application requires pipe diameter in the 2. Keep in mind that for any given application, pipe diameter should be slightly larger for a single exhaust system than for a dual system. However, bigger is not always better. If the pipe is too large in diameter, you lose exhaust flow velocity, which can actually hurt engine performance.

Pay attention to the entire undercarriage for clearance issues. Placing pipes too close to the floor can lead to excessive heat transfer to the floor and carpet. Also, if the pipes are close enough to the floor, frame, or subframe they can make contact, resulting in annoying banging or irritating resonance noise. Unlike some race cars that have a solid-mounted engine, street vehicles feature engine and transmission mounts that provide a bit of compliance.

Precise mandrel bending allows a header manufacturer to achieve a precision Make sure that the pipes clear the transmission and driveshaft properly. If the pipes are too close to the transmission, the transmission fluid temperature could elevate, which could potentially result in transmission damage. Generally speaking, I maintain at least a 1-inch clearance between any exhaust pipe and the transmission or the transmission cooling lines.These are the best-flowing factory manifolds and are sought after by circle-track racers restricted to factory pieces.

Although the factory big-block exhaust manifolds had decent flow, they absolutely respond favorably to a set of well-designed headers because of the unavoidable manifold restrictions in a tight engine compartment. Headers have been available for the small- and big-block Chevy engine for many years; by now the best designs have certainly been rethought many times.

Shorty, equal length, long, Tri-Y, large, or small tube are the common header terms to contend with when on the hunt for headers.

Shorty headers are presently all the rage; many folks like the lower cost with the look of headers. The other positive is they can be easily connected to a stock exhaust system. Shortys promote slight gains in exhaust flow while looking better than the cast-iron rams-horn manifold, although they are not the best choice for serious power gains.

Headers use primary tubes connecting each cylinder into a merge collector. Long, equal-length primary tube headers promote cylinder power balance and increase flow. This is where you also need to be careful: not all long-tube headers are equal length. Headers may be advertised as long-tube, but in reality the tube lengths are designed to work in a crowded engine compartment with the least hassle. Equal-length longtube headers are difficult to design; the primary tubes have to twist their way through the engine compartment, passing by many obstacles.

You also have to watch out for poor-fitting headers that can cause hot spots around fuel lines and coolant hoses. Sometimes you have to compromise for the ultimate power gain, dealing with tight-fitting tubes and other components that get in the way. Many first-time performance engine builders want headers with primary and collector tube size diameters that are too large.

The rule of thumb is to choose a header with a primary tube size 10 percent larger than the exhaust valve.

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Professionals start with that simple algorithm and then make minor modifications from there. For instance, a small-block cylinder head with 1. Header tube size also affects torque versus high-RPM exhaust flow. Using a set of smaller 1.

This would be beneficial if your engine has lower compression 9. The 1. The larger primary tubes would be applicable with the 3. The PerTronix shorty header right has similar tubing bends with close to equal-length tubes. Longtube headers typically flow better at high RPM while the shortys provide more torque. Shortys are suitable for the street-driven Shark that occasionally goes to the track. They free up the stock manifold restrictions, especially the — factory stainless manifolds.

If you want all-out high-RPM performance, the long tubes are for you. Engine compartment fit is similar with some additional tight spots on the long-tube set as they work their way around the starter. Gear reduction starters are recommended to get some clearance between the starter and the header tubes.

The same rules apply to big-blocks to a lesser degree: the large-cubic-inch engine has more available torque. It makes sense to use a set of 1. Whether you are working with rectangular-port cylinder heads with 1.

how to connect headers to exhaust pipe

Moving up to the 2. Header collectors terminate the primary tubes into one large tube for the exhaust pipe connection. Contrary to what many think, larger collectors do not always mean more power. For example, take the primary tubes; torque can suffer if the collector diameter is too large. The general rule goes like this: small-block 1.


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