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Borla XR-1 Multi-Core 4in Ctr-Ctr Round 16in x 6.25in Rotary Engine Equipped Racing Muffler

SKU: BOR400374

Mufflers

BOR XR-1 Mufflers...

Borla

Borla XR-1 Multi-Core 4in Ctr-Ctr Round 16in x 6.25in Rotary Engine Equipped Racing Muffler

SKU: BOR400374

Mufflers

BOR XR-1 Mufflers...

Available from MFR. This item is available from the manufacturer's distribution centre. The dispatch timeframe shown is an estimate based on historical order processing and release times for this part. This item is not held in our own warehouse, and actual dispatch timing may vary depending on manufacturer workload and logistics at the time of ordering.

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Description

XR-1(r) Multi-Core Racing Muffler. 3" Center Inlet/ 3" Center Outlet 6.25" Round x 16" Long Body 21" Overall Length. Long body design works well on SUV & truck applications but can be used on a wide range of vehicles. It features BORLA(r)'S patented Multi-Core 4 tube design for maximum flow, horsepower, and torque. The Multi-Core portion of XR-1(r) mufflers flows better than straight tubing. Recommend for high horsepower applications. Reversible design for installation flexibility. T-304 Stainless steel for superior corrosion resistance. Natural mill finish can be brushed or polished prior to installation. 100% welded construction for strength. High-temperature continuous-filament fiber (CFF) acoustic material for sound control. There is no BORLA(r) logo embossment on this part. Best of all, it's made in the USA. Just what you’d expect from the world’s most experienced (and most winning) exhaust brand.

Product Overview

BORLA XR-1 Raceline products are the choice of todays hottest drag and oval track racers. Featuring a patented uninerrupted-flow design and multicore technology. BORLAs XR-1 mufflers actually outflow a straight piece of pipe in repeated testing. XR-1 race products are light weight and constructed of high quality austenitic stainless steel for track-tough durability. They meet the strictest noice requirements and use sound absorbing stainless steel pcking to protect against burnout. Hands down, BORLAs XR-1 Raceline offers the best balance of sound and power.

Product Details

Body Height (in.):	6.25
Body Height:	6.250 in.
Body Length (in.):	16
Body Length:	16.000 in.
Body Width (in.):	6.25
Body Width:	6.250 in.
Construction:	All Welded
Description:	XR-1Ã‚Â® Stainless Multicore Racing Mufflers
Grade Type:	Performance
Inlet Connection Type:	Pipe
Inlet Position:	Center
Inlet Size (in.):	4
Inlet Type:	Single Center
Main Piping Diameter:	4.000 in.
Material:	T-304 Stainless Steel
Muffler Count:	1
Off Road Use Only:	No
Outlet Outside Diameter:	4.000 in.
Outlet Position:	Center
Outlet Size (in.):	4
Outlet Type:	Single Center Outlet
Overall Length (in.):	21
Overall Length:	21.000 in.
Part Number:	bor400374
Position:	N/A
Prop 65 (C, R or CR):	CR
Prop 65 - Long Label:	WARNING: This product in the physical form it is sold does not present a hazard. However, operations including, but not limited to welding, brazing, or thermal cutting can expose you to chemicals including Chromium, Nickel, Cobalt, Arsenic, Cadmium and Lead which are known to the State Of California to cause cancer, birth defects and other reproductive harm. For more information go towww.P65Warnings.ca.gov
Prop 65 - Short Label:	Proposition 65 Warning.JPG
Prop 65 Yes/No:	Yes
Shape:	Round
Tip / Outlet Finish:	N/A
Title Extended:	XR-1 Multi-Core 4in Center-Center 16inx6.25in Round - Rotary Engine Equipped Racing Muffler Part # 400374
Title:	XR-1 Multi-Core Racing Muffler 4in Center Inlet/ 4in Center Outlet 6.25in Round x 16in Long Body Rotary Engine Equipped Vehicles

Application Summary

XR-1? Multi-Core Racing Muffler For Rotary Engine Equipped Vehicles - 4" Center Inlet/ 4" Center Outlet 6.25" Round x 16" Long Body 21" Overall Length. Universal Part. Reversible Design.

Part Type

Exhaust Muffler

Data: v4.2 - Upd: 2026-10-14 02:09:54

Features

4" Center Inlet/ 4" Center Outlet 6.25" Round x 16" Long Body 21" Overall Length'Multi-Core 4 tube internal design
Can be used on a wide range of vehicles
Long body design works well on SUV & truck applications
Multi-Core 4 tube internal design
Universal muffler. Reversible design. No BORLA(r) logo embossement.

Specifications

Product Attributes - Brand: Borla
Product Attributes - Manufacturer's Part Number: 400374
Product Attributes - Part Type: Mufflers
Product Attributes - Product Line: Borla XR-1 Racing Mufflers
Product Attributes - UPC: 808422003742
Product Attributes - Muffler Material: 304 stainless steel
Product Attributes - Inlet Diameter (in.): 4.00 in.
Product Attributes - Outlet Diameter (in.): 4.00 in.
Product Attributes - Inlet Quantity: 1
Product Attributes - Outlet Quantity: 1
Product Attributes - Internal Construction: Straight-through core
Product Attributes - Inlet Location: Center
Product Attributes - Outlet Location: Center
Product Attributes - Case Shape: Round
Product Attributes - Reversible: No
Product Attributes - Muffler Finish: Brushed
Product Attributes - Case Exterior Length (in.): 16.00 in.
Product Attributes - Case Outside Diameter (in.): 6.25 in.
Product Attributes - Outlet Style: Standard, without tip
Product Attributes - Remanufactured: No
Product Attributes - Quantity: Sold individually.
Product Attributes - Notes: Multi core design. Features stainless steel sound absorbing material to protect against burnout.

Reference Information

Brand Name/s	Borla
StreetFX SKU	bor400374
SFX Item ID	4225186
Supplier Item Code	4225186
Manufacturer SKU	400374
Manufacturer UPC	808422003742
Alternative References	xr-1, 4in, 16in, 6.25in

Brochures

Primary brochure

Compatibility

XR-1? Multi-Core Racing Muffler For Rotary Engine Equipped Vehicles - 4" Center Inlet/ 4" Center Outlet 6.25" Round x 16" Long Body 21" Overall Length. Universal Part. Reversible Design.

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