aFe® 51-81072 - Magnum Force™ Stage 2 Si Aluminum Cold Air Intake System with Pro Dry S Filter

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aFe® - Magnum Force™ Stage 2 Si Air Intake System
aFe® - Magnum Force™ Stage 2 Si Air Intake SystemaFe® - Magnum Force™ Stage 2 Si Air Intake SystemaFe® - Installation InstructionaFe® - CatalogaFe® - Factory Tour Video 602x420Made In USAaFe Authorized Dealer
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Product Details

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aFe Accessories

Magnum Force™ Stage 2 Si Aluminum Cold Air Intake System with Pro Dry S Filter (51-81072) by aFe®. Filter Color: Gray. System Type: Cold Air Intakes. Material: Aluminum. HP Gain: up to 11 hp. TQ Gain: up to 23 lbs./ft. Includes: Air Filter, Heat Shielding Molded Housing, Black Aluminium Cover, Heat Insulating Roto-Molded Tube. The aFe Stage 2 Si Cold Air Intake System replaces your entire factory air intake system with a large high-flow aFe air filter, a totally enclosed airbox and a smoothly contoured, less restrictive intake tube. This system enables your engine to take in huge quantities of dense, cool, oxygen laden air. The result is better combustion, increased horsepower and torque, and a noticeable gain in performance.

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  • Filter Color: Gray
  • System Type: Cold Air Intakes
  • Material: Aluminum
  • HP Gain: up to 11 hp
  • TQ Gain: up to 23 lbs./ft.


  • Improves airflow to your enginer
  • Isolates the air filter from engine heat, enabling it to take in cooler, denser air
  • Increases horsepower and torque, improves performance
  • Designed and tested for each specific application
  • Includes a conical high performance aFe air filter
  • Includes a precision designed molded, sealed plastic airbox and plastic intake tube
  • Comes complete with everything required for installation, including comprehensive instructions
  • Can be installed in 45-90 minutes with simple hand tools; no drilling, cutting or fabrication required
  • Limited 2-year warranty
  • Proudly made in the USA

The Stage 2 Si Cold Air Intake System is for those who want a substantial performance gain with less intake noise and a stock appearance. It replaces your factory, restrictive air intake system with the massive aFe performance air filter of your choice, a sealed plastic air box that isolates the filter from engine heat and quiets intake noise, and a rotomolded plastic intake tube with smooth bends for increased airflow volume. The increased flow of cooler air to your engine will result in noticeable gains in power and performance. Cooler, denser air contains more oxygen, and more oxygen in your engine's air intake charge means better combustion, resulting in greater engine output.

The aFe Pro 5R air filter was designed to provide the maximum airflow possible, to enable your engine to make the most horsepower and torque. But aFe didn't achieve this by ignoring engine protection. The Pro 5R outperforms most other cotton gauze air filters with a 98.6% efficiency rating. The increased airflow and high filtration capability are the result of the Pro 5R's construction. It's made of 5 layers of progressively finer medical-grade cotton gauze.

Competitors use constant size mesh gauze in their filters, which creates voids/openings that can allow dirt to pass through. As the progressively finer layers of gauze are stacked in the Pro 5R, the randomness of the openings increase, minimizing spaces with no filter media. Dust accumulates on multiple layers, increasing overall dust holding capacity and filtration efficiency.

The Pro DRY S filter combines high airflow and filtration efficiency with the convenience of oil-free maintenance. It contains 2 layers of randomly porous synthetic fabric, which allows approximately twice the airflow when compared to a typical stock air filter. The increased airflow results in more horsepower and torque, better throttle response and more miles per gallon. But this improved airflow and performance hasn't been gained at the expense of engine protection. The Pro DRY S has an excellent 99.2% filtration efficiency rating.

The pleats in both filters are evenly spaced for greater dust holding capacity and the tips are rounded for better airflow. They're also 30% deeper than comparable aftermarket air filters for longer service intervals and greater dust holding capacity. The sealing surface and supporting structures are made from 100% polyurethane, to withstand extreme engine temperatures.

The one-piece sealed plastic airbox may install in the same location as the factory airbox, but there the similarity ends. The Stage 2 Si airbox is much larger inside in order to include the largest aFe filter possible. The air box also features strategically located openings and scoops to ensure that only the coolest air is forced into the air filter for greater efficiency and performance. And enclosing the air filter also results in less intake noise. The Stage 2 Si airbox installs easily; no cutting or drilling is required, and it's attached with quality stainless steel hardware supplied with the kit.

A specially developed 3-angle velocity stack smoothes the airflow transition from the air filter to the rotomolded intake tube. The precision design and smooth contours of the intake tube maximize airflow volume and speed for optimum power gains. The intake tube also features a precision tuned MAF sensor pad, which will not affect engine performance or cause a CHECK ENGINE light.

The aFe Stage 2 Si Cold Air Intake System comes complete with everything necessary for installation, including comprehensive instructions. It's backed by aFe's limited 2-year warranty and made in the USA.

aFe® (Advanced Flow Engineering, Inc.) manufactures performance products for late model cars, light trucks and SUVs. The company was founded in 1999 with an initial concentration on high performance air filters. Since then, the company product line has broadened to include cold air intakes, fluid filters, exhaust systems, intake manifolds, intercoolers, programmers, differential covers, transmission pans and throttle body spacers. The team of engineers, machinists, production and sales people at aFe® have many years of experience in their respective positions, and together work to ensure they produce the best automotive products on the market.

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Warranty Information

Find out everything you need to know about the product warranty

aFe warrants their products to be free from manufacturer's defects due to workmanship and material. This warranty applies only to the original purchaser of the product and is non-transferable. Proof of purchase of the aFe product is required for all warranty claims. Warranty is valid provided aFe instructions for installation and/or cleaning were properly followed. Proper maintenance with regular inspections of product is required to insure warranty coverage. Damage due to improper installation, abuse, unauthorized repair or alteration is not warranted. Incidental or consequential damages or cost, including installation and removal of part, incurred due to failure of aFe product is not covered under this warranty. All warranty is limited to the repair and/or replacement of the aFe part.

  • Direct OE Replacement Filters: Life of the vehicle
  • Racing Filters : 1-year
  • Universal : 2-years
  • Air Intake Systems : 2-years
  • Exhaust Systems : 2-years
  • Intercoolers and Intercooler Tubes : 2-years
  • Intake Manifolds : 2-years
  • Exhaust Manifolds : 2-years
  • Throttle Body Spacers : 2-years
  • Fluid Filters : 90-days
  • Pre-Filters : 2-years
  • Suspension: 20X, 40X, 50X 1 year

No other warranty expressed or implied applies nor is any person or advanced FLOW engineering authorized to assume any other warranty. Some States do not allow the exclusion or limitation of incidental or consequential damages or do not allow limitations on how long an implied warranty lasts, so the above limitations or exclusions may not apply to you. This warranty gives you specific legal rights, and you may also have other rights which vary from State to State.

Magnuson-Moss Warranty Act:
Legally, a vehicle manufacturer cannot void the warranty on a vehicle due to an aftermarket part unless they can prove that the aftermarket part caused or contributed to the failure in the vehicle (per the Magnuson Moss Warranty Act (15 U.S.C. 2302(C)) Learn More

Vehicle Fitment

This part is compatible with 18 vehicle(s)
Year Make Model Fitment Notes:
2008 Cadillac Escalade / Escalade ESV / Escalade EXT
  • GMT900 Body Model
2008 Chevy Avalanche
  • GMT900 Body Model 5.3L
2008 Chevy Silverado
  • 1500 GMT900 Body Model 4.8L / 5.3L
2008 Chevy Suburban
  • GMT900 Body Model 5.3L
2008 Chevy Tahoe
  • LS / LT GMT900 Body Model
2008 Chevy Tahoe
  • LTZ GMT900 Body Model 5.3L
2008 GMC Sierra
  • GMT900 Body Model 4.8L / 5.3L
2008 GMC Sierra Denali
  • GMT900 Body Model
2008 GMC Yukon
  • SLE / SLT GMT900 Body Model
2008 GMC Yukon XL
  • GMT900 Body Model 5.3L
2008 GMC Yukon Denali / Yukon XL Denali
  • GMT900 Body Model
2007 Cadillac Escalade / Escalade ESV / Escalade EXT
  • GMT900 Body Model
2007 Chevy Avalanche
  • GMT900 Body Model 5.3L
2007 Chevy Silverado New Body Style
  • 1500 GMT900 Body Model 4.8L / 5.3L
2007 Chevy Suburban
  • GMT900 Body Model 5.3L
2007 Chevy Tahoe
  • GMT900 Body Model
2007 GMC Sierra New Body Style
  • GMT900 Body Model 4.8L
2007 GMC Sierra New Body Style
  • SLE / SLT / WT GMT900 Body Model 5.3L
2007 GMC Sierra Denali New Body Style
  • GMT900 Body Model
2007 GMC Yukon
  • SLE / SLT GMT900 Body Model
2007 GMC Yukon XL
  • GMT900 Body Model 5.3L
2007 GMC Yukon Denali / Yukon XL Denali
  • GMT900 Body Model

All manufacturer names, symbols, and descriptions, used in our images and text are used solely for identification purposes only.
It is neither inferred nor implied that any item sold by, is a product authorized by or in any way connected with any vehicle manufacturers displayed on this page.