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- USA
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- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 9 - Jul 14
For Your Every Summer RSVP, with Code: SUMMER15
Description
Borla 40976 - XR-1 Multicore Collector Muffler ShortyThis is the HOT set up in drag racing. This patented, award and race winning vacuum Wave Collector was designed to replace your current open header collector and serves as a power producing merge collector and muffler all in a single unit. The technology in this unit results in pulling air through the engine faster, which creates more power. When an exhaust valve opens, an energy wave is created from the expanding combustion gases. When this wave
This is the HOT set up in drag racing. This patented, award and race-winning vacuum Wave Collector was designed to replace your current open header collector and serves as a power producing merge collector and muffler -- all in a single unit. The technology in this unit results in pulling air through the engine faster, which creates more power. When an exhaust valve opens, an energy wave is created from the expanding combustion gases. When this wave encounters a lower pressure area such as a larger collector pipe or the atmosphere, a reversion wave is reflected back toward the exhaust valve. Borla's Vacuum Wave Collector Muffler ensures this wave's "anti-node" reaches the exhaust valve at the precise time for its lower pressure to help fill the combustion chamber with a fresh charge and to further extract spent gases from the chamber via a vacuum effect. Made with the same patented, award and race winning flow through design as the Standard XR-1(r) Collector/Muffler. This muffler, however, is designed for door car applications where a Standard size Collector/Muffler is too large. This muffler is recommended for Full Chassied Cars. Accepted in NHRA, IHRA, Hot Rod Series, Brackets, Super Chevy, and NSCA. Recommend for high horsepower applications. T-304 Stainless steel will never rust. 100% welded construction for strength. T-304 stainless steel wool for sound control. 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.
Specifications:
| Description_ASM | XR-1(r) Multicore Shorty Collector Racing Muffler - (4) 2.25" Inlets (1) 4" Outlet 6.75" Round x 14" long Body 16" Overall Length. Universal Part. |
| Description_DEF | Exhaust Muffler |
| Description_DES | XR-1 Multicore Collector Muffler Shorty |
| Description_EXT | XR-1 Multi-Core Shorty Collector Racing Muffler - 2.25" Inlets (4)/ 4" Outlet 6.75" Round x 14" long Body 16" Overall Length. Universal Part. |
| Description_INV | Borla(r) XR-1 Collector Muffler |
| Description_MKT | This is the HOT set up in drag racing. This patented, award and race-winning vacuum Wave Collector was designed to replace your current open header collector and serves as a power producing merge collector and muffler -- all in a single unit. The technology in this unit results in pulling air through the engine faster, which creates more power. When an exhaust valve opens, an energy wave is created from the expanding combustion gases. When this wave encounters a lower pressure area such as a larger collector pipe or the atmosphere, a reversion wave is reflected back toward the exhaust valve. Borla's Vacuum Wave Collector Muffler ensures this wave's "anti-node" reaches the exhaust valve at the precise time for its lower pressure to help fill the combustion chamber with a fresh charge and to further extract spent gases from the chamber via a vacuum effect. Made with the same patented, award and race winning flow through design as the Standard XR-1(r) Collector/Muffler. This muffler, however, is designed for door car applications where a Standard size Collector/Muffler is too large. This muffler is recommended for Full Chassied Cars. Accepted in NHRA, IHRA, Hot Rod Series, Brackets, Super Chevy, and NSCA. Recommend for high horsepower applications. T-304 Stainless steel will never rust. 100% welded construction for strength. T-304 stainless steel wool for sound control. 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. |
| Description_SHO | XR-1 Collector |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
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Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.2 ★★★★★
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Product Reviews
★★★★★ 5
They’re fantastic!!!!
Size: X-Large, Color: Multicoloured E-(5-pack)
My clothing size is 16/18 and XL. Even though Amazon suggested a size XXL, I ordered my normal XL and they fit perfectly.
The fabric for this style is 92% bamboo viscose and is amazingly soft and almost silky feeling. I had ordered a different boy short in this brand but they were 80% bamboo viscose and the fabric was significantly heavier. I returned those and ordered these.
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Reviewed in the United States on April 25, 2026
★★★★★ 5
My favorite underwear
Size: Medium, Color: Multicoloured C (5-pack)
Super comfortable!! They are soft and breathable. No pinching, no shifting, and relatively invisible in skirts, pants, and loose dresses. True to size. Excellent quality, holds up well. Only thing is that the wording on the front does come off after a few washes, so you have to differentiate the front from the back of the underwear by how high the seam comes up. I almost exclusively wear this underwear now, I love it!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 30, 2026
★★★★★ 5
Incredible Comfort
Size: Large, Color: Multicoloured F (5-pack)
Amazing; I’ll be ordering more. Super soft, lightweight, smooth under clothes, incredible comfort! Best underwear! I ordered these because I’m tired of underwear lines when wearing biker shorts/leggings. Other boy shorts were too long or the bottom hem too thick and both of those issues left lines around my upper leg. THESE are *just right* - perfect length and fit. No panty lines on close fitting pants, comfortable under other pants and dresses, great with jumpsuits, and fit well under slip shorts with dresses.
NOTE: These take longer to dry, than similar clothes, in the dryer. No shrinking though.
SIZE: I ordered these in size L and they fit perfectly. A little snug when first on but they loosened up. For reference I’m 5’4” tall, about 175#, carry my weight in my hips and backside,wear size L sweats/pajamas/loose pants, size 12 jeans.
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Reviewed in the United States on September 23, 2025
★★★★★ 5
Full coverage and full comfort
Size: XX-Large, Color: Multicoloured C (5-pack)
These boyshort underwear are a dream. They’re very soft, very stretchy, and very comfortable. They do not shrink when they’re washed. They’re heavy enough to make you feel like you have something covering you for discretion, but light enough to wear under any type of fabric. I have wide hips and I’m older so I don’t have a tight perky butt anymore. Most underwear tend to either ride up on me or become very uncomfortable. These stay where you put them. And they come all the way up to your waist so that there is no panty line whatsoever. The waist line is soft and comfortably. It does not dig in. They do not ride up and drive you crazy they stay where you put them. I would recommend them to anyone young or old. I have tried so many different styles and materials to find underwear that’s actually comfortable. These are the absolute best I have tried in five years. I just threw all the rest of them out.
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Reviewed in the United States on April 8, 2026
★★★★★ 4
Bamboo is an amazing fabric
Size: Large, Color: Multicoloured I (5-pack)
Comfy and soft . I’ve never worn boy shorts before so takes adjusting to. Legs roll sliding pants up but easy to adjust and smooth before zipping up then all day comfort. When I wear skirts or shorts they are perfect for that! I use to wear bike pants under skirts that don’t have to anymore. I like that they don’t creep up like regular underwear. I’m a new fan of bamboo fabric and bought briefs in bamboo as well.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 9, 2026
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