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Exhaust Systems

Our website is designed to be easy to use, and to be as informative as possible. Before you start looking for specific product applications, we suggest you take a few minutes to read this overview of the exhaust system components. You'll find that we've answered most of your questions and a much better understanding of your exhaust system.

Stock exhaust systems are intended to work in a wide range of driving conditions and generally are not very efficient. Car manufacturers compromise performance for other considerations, such as ease of production and cost. Typically a single log-type manifold on each cylinder bank connects through a "Y" pipe into a single catalytic converter and muffler, with an overall pipe diameter of 2" or even less. This is okay for a grocery-getter, but not when you're looking for low-end power, mid-range acceleration, top speed potential, and yes, even better fuel efficiency.

Anything that causes turbulence or excess back pressure in your exhaust system reduces the power that intake or engine modifications can make. Stock manifolds contribute heavily to turbulence because all the exhaust gases dump directly into a single tube or chamber in the manifold. Tubular header designs separate each cylinder's exhaust pulse, reducing the possibility that spent gases will flow back into an adjacent cylinder and contaminate the incoming fuel and air mixture. This is especially crucial when you are running a camshaft in your engine that has more valve overlap.

Simultaneously, tubular headers reduce back pressure, allowing more fuel and air to enter each cylinder's intake stroke. Both these factors add up to more combustion efficiency ~ more power to the wheels! Exhaust performance system/boxes upgrades will give you a noticeable performance gain; even when connected to an otherwise stock exhaust system. But it only makes good sense to look at all the exhaust system components from front to back. Certainly, restricting the headers is a small single pipe system defeats the reduced back pressure and increased airflow you're trying to achieve.

A properly sized single exhaust or dual exhaust with crossover pipe is an important first priority. From there, choosing each component to work for you gets easier. The information below will help you decide what you need to get the most from your stock or modified engine.

Header Styles

Blockhugger: Designed for use where engine to chassis clearances are especially tight, typical in street rods and smaller street machine engine compartments.

Full-Length: Also a tight-fitting inside chassis header. Longer primary tubes empty into collectors which point straight back. This style makes connection to the rest of the exhaust system easier when space permits.

Roadster: Outside-chassis designs for traditional T-Bucket, Highboy, Sprint Style, and other open fender applications. Options include turnouts with internal mufflers or adapters to connect to an under chassis exhaust system. All Everest Motors Ltd piping employ up to 3½" diameter piping.

Reducers and Adapters

Everest Motors Ltd employ either a 2½" or 3" collector diameter (outside chassis roadster headers are 3½"), depending on the size of the primary tubes. many of our blockhugger designs point directly down and are furnished with angle reducers. These make it easier to connect your exhaust system. Models with collectors which angle to clear steering or other chassis components come with a mating flange which simply welds to the end of your exhaust pipe, minimizing the space required for the transition.

Full length headers with 3' collectors come with straight reducers to weld onto 2½" pipes. Those with 2½" collectors come with a weld-on mating flange. If your application is unique, both straight and angle reducers are available separately under the Accessories category.

Important: A special reducer is not required to mate a your headers to a 2¼" or 2" exhaust system. Simply swedge (enlarge with a tapered round mandrel) the end of your exhaust pipe. It takes only a couple minutes and saves the cost of a custom reducer.

Crossovers, Converters & Mufflers

Mufflers and catalytic converters have been vastly improved over the years, and are available for high performance applications. When used as part of a totally designed system, they can actually increase torque and horsepower (even over un-mufflered or open exhaust systems)! We recommend Flowmaster and Magnaflow products to customers who are having their installation work done in our shop.

Crossover pipes are important on dual exhaust systems so as to balance the exhaust pulses on a V-type engine. By installing a crossover, H-pipe, or X-pipe in your system you will even out the sound to get rid of the cackling, but also increasing the torque and power output. The old school way to determine proper location for the crossover was to spray a stripe of black lacquer paint on each exhaust pipe around the transmission area. A stripe about 18-24" long starting about the bellhousing and ending at the transmission mount was usually accurate. Now take the vehicle out and buzz it down the freeway for a few minutes. Come back and look under the vehicle for where the lacquer has started to bubble or come off. It is at those locations you would make the connection of the crossover pipe.

System Sizing Guidelines

One of the most critical decisions to make when you are building a performance exhaust system is pipe size. Bigger is not always better (read Let's Get Technical article). It's very important that the exhaust pipe diameter be sized appropriately to the application and that it remains the same from the collector to the end of the tailpipe. Changing the diameter up or down can confuse the exhaust by creating turbulence and excessive back pressure.

These sizing guidelines are reprinted by courtesy of Flowmaster, one of the most respected exhaust technology companies in the industry.

The size of tubing used in an exhaust system is a critical item to consider. Tubing diameter will affect the sound level and performance characteristics of the muffler, but keep in mind that bigger is not always better. Using tubing that is too large can actually hinder exhaust scavenging by slowing the velocity of exhaust pulses in the tubing. As a rule, most mild street applications (V8 dual exhaust) use 2.00” through 2.25” tubing, and modified street applications (V8 dual exhaust) will generally use 2.25” or 2.50” tubing. Very rarely will 3.00” tubing be used for (dual exhaust) street applications. In general, the following guidelines should be applied for street applications. Remember, these are general guidelines only and specialized applications may differ somewhat. - Flowmaster

Tubing Size
Dual Exhaust
Single Exhaust
up to 200 HP
up to 100 HP
up to 325 HP
up to 160 HP
up to 500 HP
up to 250 HP
up to 600 HP
up to 300 HP

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