ISR Performance - Universal Silicone Coupler - 3.50" to 4.00" Reducer

The ISR Performance Universal Silicone Coupler is a straight reducer that transitions from 3.50-inch to 4.00-inch piping. Built from 4-ply reinforced silicone for extreme temperature and pressure environments, it's a direct fit for any custom intercooler piping, intake, or charge pipe application using these tube sizes.

What It Does

Silicone couplers connect two sections of piping in custom intercooler, intake, or boost piping setups. Reducer couplers specifically transition between two different pipe diameters, which is required when you're routing piping through tight spaces or matching mismatched component sizes (turbo outlet to throttle body, intercooler core to charge pipe, etc.). The 4-ply silicone construction handles the heat and boost pressure that lower-quality couplers fail under.

Specifications

• Inlet diameter: 3.50 inches
• Outlet diameter: 4.00 inches
• Angle: Straight
• Construction: 4-ply reinforced silicone
• Application: Intercooler piping, intake, charge pipe, custom plumbing

Fitment

This is a universal coupler. It fits any application using 3.50-inch and 4.00-inch outer-diameter piping. Verify your pipe ODs before ordering, especially on custom builds where tube sizing may vary.

What's Included

• 1x Silicone coupler (sold individually)

Note: Hose clamps are not included and must be sourced separately. T-bolt clamps are recommended for boost applications.

Product Details

Brand: ISR Performance

Part Number: IS-350400

Type: Universal silicone reducer coupler

Inlet Diameter: 3.50 inches

Outlet Diameter: 4.00 inches

Angle: Straight

Construction: 4-ply reinforced silicone

Temperature Range: Engineered for high-temperature applications

Sold: Individually

Clamps Included: No

Legality: Off-road and competition use only