Flowmaster X-PIPE 81107 User Manual

409S® Stainless Steel
This X-pipe assembly is designed to be used with either the factory mufflers or a Flowmaster axle-
back system. The steps on the following two pages are intended for customers replacing the center
resonator of their vehicle and retaining the use of the factory Mustang mufflers. If you are using the
new Flowmaster X-pipe along with a Flowmaster axle-back system, please see pages 3 thru 5 below.
10/10/16
Removal:
1) Raise the vehicle up on a hoist or rack to working height. If you don’t have access to a hoist or
rack, raise the vehicle and support securely with jack stands. To ease the removal of the stock
system, spray a penetrating lubricant onto the bolts of the two clamp connections just forward of the
center resonator.
2) Begin by measuring back 2 ½” from the beginning of
the straight area shown in the photo at left and make a
mark on both pipes. Support the exhaust system both in
front and behind the area to be cut. Check that the marks
are correct, then using a sawsall, cut both pipes at the
marks. Note: Due to the closeness of the pipes to the
gas tank, use caution when cutting! Carefully deburr the
end of the muffler inlet pipes where cut with a file or die
grinder.
Pg 1 of 6 Technical Support (707) 544-4761
Installation Instructions for:
X-PIPE #81107
2015-2017 MUSTANG
3.7L · V6 ENGINE
Fits Fast-Back and Convertible Models.

Flowmaster X-PIPE 81107 Specifications

General

Part Number	81107
Product Type	X-Pipe
Pipe Diameter	2.5 inches
Inlet Diameter	2.5 inches
Outlet Diameter	2.5 inches
Finish	Natural
Compatibility	Universal
Mandrel Bent	Yes

Summary

Exhaust System Removal

Prepare Vehicle for Removal

Raise vehicle on hoist or rack, support securely with jack stands if needed.

Cut Factory Exhaust Pipes

Measure and cut pipes 2.5 inches from the beginning of the straight area.

Exhaust System Installation

Install Adapter Pipes

Slide supplied adapter pipes onto X-pipe outlets and secure with clamps.

Mount X-Pipe Assembly

Position X-pipe behind downpipes, slide clamps to stops, ensure correct orientation.

Connect Stock Mufflers to X-Pipe

Slide stock mufflers onto X-pipe adapter pipes and tighten slip-fit clamps.

Axle-back System Removal

Prepare for Axle-back Removal

Lift vehicle, lubricate hangers and clamps for easier disassembly of axle-back system.

Loosen Axle-back Muffler Clamps

Support center resonator, loosen clamps at axle-back muffler inlets.

Detach Axle-back Mufflers

Loosen hanger mounts and slide muffler assemblies rearward to remove from vehicle.

Axle-back System Installation

Mount X-Pipe to Downpipes

Place X-pipe behind downpipes, attach factory clamps to bump stops, ensure forward position.

Connect Axle-back Mufflers to X-Pipe

Slide axle-back muffler inlets onto X-pipe adapter pipes and tighten clamps.

Final Exhaust System Adjustment

Level system, ensure 1/2-inch clearance, then securely tighten all clamped connections.