E90 e91 header

Types of e90 e91 header

There are several types of E90 and E91 header, which are generally based on the specific needs and characteristics of different car models. The characteristics of each type reflect the construction material, design intent, and performance benefits.

OEM E90/E91 Headers

An Original Equipment Manufacturer header can be defined as a factory replacement header. OEM E90/E91 headers are manufactured to the same specifications as the original headers fitted in the cars at the factory. They are designed to give a perfect fit and ensure no major changes are required during installation.

OEM headers come in these benefits:

• Uphold functionality and reliability
• Maintain resale value because of genuine part installation

Stainless steel headers

They are primarily manufactured using stainless steel, a corrosion-resistant alloy known for its durability and aesthetic finish. Common areas to find stainless steel used in automotive parts due to their strength, heat resistance, and lifespan. Stainless steel headers are particularly suited for those who live in regions exposed to harsh weather elements or who want a part that will last long and look good.

Ceramic coated headers

Applying ceramic coating to an alloy steel or mild steel header provides additional heat resistance and a shield against corrosion. The ceramic layer coating is a heat-resistant and ceramic coating application that reduces the amount of heat trapped in the header. Thus, the engine stays cooler, and there is improved air conditioning for the passengers.

Apart from the cooling benefits, the ceramic coating gives a more sleek and shiny finish to the header with a coat available in several colors, mainly black and silver.

Shorty headers

Installing Shorty header is common among people who drive Ford E90 and E91 cars. Shorty headers are a type of performance header designed to replace the factory exhaust manifold. They are shorter than long header pipes but longer than the factory stock exhaust manifold.

The average E90 and E91 shorty header pipes are designed to offer better exhaust flow than the stock exhaust manifold. A simple bolt-on replacement header is easier and quicker to install, requiring no major changes or modifications to the car's exhaust system. It is suitable for users who are looking for minor performance enhancements for daily driving.

Long tube headers

Long tube headers are ideal for performance enthusiasts and racing applications. They are designed to maximize exhaust flow and decrease back pressure to improve engine power and efficiency. Long tube headers require more complex installation involving modifications to the exhaust system.

Function, Feature, and Design of e90 e91 header

Function

The main function of E90 E91 header pipes is to direct exhaust gases from the engine's exhaust valves through the exhaust system. The key functions of E90 and E91 headers include:

• Improved exhaust flow: E90 and E91 performance headers are designed to enhance the exhaust flow compared to stock headers or exhaust manifolds. This is As long tube headers feature longer and larger diameter of pipes, which reduces the resistance that the exhaust gases encounter when exiting the engine.
• Increased power and torque: Enhanced flow above leads to better engine scavenging and thus allowing the Intake of fresh air into the combustion chamber. This results in improved combustion and an increase in the power and torque output of the engine.
• Sound modification: Performance header pipes change the exhaust note and make the engine sound deeper and more aggressive. Different header designs create different exhaust sounds.

Feature

• Material composition: E90/E91 headers are commonly manufactured from stainless steel, mild steel, or titanium. Each material has its own benefits: mild steel is usually cheap and easy to weld, stainless steel is durable and corrosion-resistant. Titanium is extremely light and durable.
• Coating and finishing: Standard E90/E91 stock headers are finished or coated with various coatings. These include ceramic coating, chrome plating, or powder coating. These finishes provide additional corrosion resistance, heat retention, and aesthetic appeal.
• Tube design: E90 and E91 headers are commonly featured in different tube designs, like equal length and uneven length. While equal length tubes ensure that all exhaust pipes are of the same length, unequal length allows for better scavenging of exhaust gases, thus improving the engine combustion process.

Design

The design of E90 and E91 headers aims to improve performance and fitment. The key aspects of this include:

• Primary tube diameter: E90 and E91 header pipes are characterized by varying primary tube diameters, which are typically between 1.5 and 2.5 inches depending on the make and model of the car and the purpose intended for the header. Larger tubes are suitable for high-performance engines, while smaller tubes should be ideal for normal everyday driving.
• Collector design: Collector style refers to where all primary tubes converge into a single outlet. Different collectors affect the exhaust flow, with designs like merge collectors enhancing the exhaust merging and flow compared to stock devices, thus improving performance.

Scenarios of e90 e91 header

E90 and E91 headers are applicable in various scenarios, depending on the user's requirements. From daily driving to racing, the practical application of these headers varies by performance needs and emission regulations.

Daily driving

For daily drivers, E90/E91 headers provide slight performance gains without the complexity of installation or emissions system realignment. Stock replacement headers or shorty headers are appropriate options for daily commutes. They provide enhanced exhaust flow compared to factory exhaust manifold. This flow is modest enough to improve engine efficiency and power while maintaining reliability.

Racing or performance tuning

Long tube E90 and E91 headers are a preferred option for people participating in racing or dyno trials. These are designed to offer maximum exhaust flow and provide better engine scavenging effects. They help to maximally increase power output. They are also useful for bracket racers or road course racers who need any extra horsepower and torque to improve their performance. Long tube headers are also applicable to turbochargers or superchargers for potential maximum performance.

Tow vehicles or off-road cars

Vehicles that normally function under heavy loads, like trucks, SUVs, or towing E90 and E91 cars, will benefit from upgraded headers, too. Header coatings like ceramic or titanium heat wrap help minimize heat absorption in vehicles under constant load. The cooler operating temperature helps improve performance and longevity in vehicles operating under constant stress.

Custom builds or swaps

In custom engine swap builds or projects where the E90 or E91 engine is fitted into another chassis, aftermarket headers are used. They are adapted to fit this unique configuration for optimal exhaust flow. Long tube headers and shorty headers are specifically used in these cases depending on space availability and intended performance goals.

Compliance with emissions regulations

Replacing stock headers or using shorty headers is ideal for users residing in areas with strict emissions laws or periodic smog checks. They facilitate better exhaust gas emissions and are easier to install without modifying the existing exhaust system and emissions components like catalytic converters.

How To Choose the e90 e91 header

Selecting an appropriate E90/E91 header involves considering various factors that influence the performance, compatibility, and practicality of the replacement part.

Budget

The header prices vary from materials, design complexity, and manufacturing techniques. Mild steel headers are cheaper; titanium and stainless steel headers are more expensive due to their durability and corrosion-resistance properties. Budget also entails installation costs, especially for long tube headers requiring extensive modification.

Vehicle usage

Define the purpose of the vehicle to help choose an ideal header comfortably. Daily-driven E90 or E91 cars will benefit from shorty or factory-style headers. These are easier to install and have moderate performance enhancement. Race cars or high-performance vehicles may get the maximum benefit from long tube headers. Long tube headers are designed to maximize exhaust flow and power output.

Engine and modification

Consideration of engine conditions and modifications also helps determine the appropriate header. For E90 or E91 cars with stock or naturally aspirated engines, shorty headers or factory-style headers should suffice. Turbocharged engines or high-performance E90 and E91 cars will massively benefit from long tube headers. Long tube headers are designed for better exhaust flow and maximized power output.

Material

The material used to manufacture headers significantly impacts their durability, performance, and price. Stainless steel is a durable and corrosion-resistant; hence, it is a popular choice for E90 and E91 headers. Mild steel is cheaper and easier to weld but prone to corrosion if not coated. Titanium is extremely durable and lightweight. It is however too expensive and not a practical choice for a normal E90 and E91 header.

Fitment and compatibility

This is a major concern when it comes to choosing E90 and E91 headers. These compatibility and performance standards are compatible with their respective models. OEM headers are manufactured specifically to fit the vehicle with no modification required. Aftermarket headers like shorty and long tube are also designed to fit specific models but may need modification to the exhaust system or the engine bay.

Q&A

Q1. Will E90 and E91 headers fit other models?

A1.Yes, some aftermarket headers are designed to be compatible with multiple BMW models with similar engines. However, E90 and E91 headers are specifically intended to fit the E90 and E91 chassis. OEM headers are designed for their specific models. It is therefore crucial to check the product details and consult with the supplier to ensure compatibility.

Q2. Are stainless steel headers worth the money?

A2.Stainless steel headers are corrosion-resistant, durable, and better for long-term value. They will also give a lifetime performance of more than 50 years under normal day-to-day driving. On the other hand, mild steel headers are cheaper and perform well in racing conditions. They are less durable and prone to rust in areas exposed to moisture and harsh weather. While mildly steel is cheaper, stainless steel is meant for a long term investment.

Q3. Are ceramic coated headers heat resistant?

A3.Yes, ceramic coating is a heat-resistant feature that protects the header from adverse effects of heat. It traps less heat in the engine bay while dissipating into the atmosphere. This cools the engine and improves air conditioning for passengers in the car while simultaneously boosting engine power due to exhaust flow efficiency.

Q4. How do E90 and E91 headers improve exhaust flow?

A4.E90 and E91 performance exhaust headers are designed with larger diameter tubes, smoother bends, and shorter lengths. This minimizes the resistance the exhaust gases encounter when exiting the engine. This maximizes the flow rate of the exhaust gases. Reduced flow rate pressure leads to something called back pressure.

Q5. What are shorty headers, and how do they work?

A5.E90 and E91 shorty headers are aftermarket performance parts designed to replace stock exhaust manifolds. They resemble long tube headers but are shorter in length and easier to install. They provide modest gains in exhaust flow and engine performance. They do not require extensive modifications to the vehicle's existing exhaust system.