Airaid 100-400 U-Build-It 4" Universal Intake Tube – Cut-to-Fit Bends for a Custom Cold Air Intake

What it is

A single molded length of 4-inch intake tube with 30°, 45°, 60° and 90° bends built in, so you cut the sections you need and join them with silicone couplers to route an intake around whatever is in the engine bay. It is the tube half of Airaid's universal intake system; the filter, couplers and clamps come from the matching U-Build-It parts.

Fits

Anything. Typical uses: swapped engines, turbo builds and older cars with no bolt-on intake available. Measure your throttle body or turbo inlet; this is the 4-inch version (3" and 3.5" exist).

What's in the box

One molded tube assembly. No filter, couplers, clamps or sensor bungs.

Installation

Mock up the route, cut with a fine saw, deburr, join with 4" couplers. Add a MAF or IAT sensor bung if your engine needs one (Airaid sells weld-in and bolt-in bungs). An afternoon for a careful first build.

Why Airaid

Airaid (K&N group) has sold the U-Build-It range for years, and the roto-molded polyurethane tube does not conduct heat into the intake charge the way metal tube does.

Universal. 4 in OD tube for building a custom intake on any engine, pair with a 4 in filter and couplers (not included).

Fitment data from the manufacturer catalogue. Check your engine before ordering, or call us.

Shipping. Free on every order, US only. Orders arrive in 2–4 days.

Returns. 30-day returns, except in extreme cases.

Support. Our team is available 24/7 for fitment mismatches or any other reason.

Warranty. Full manufacturer guarantee.