SP Concepts Big Bore Exhaust M8 Softail 2018-Present (stainless)

SP Concepts Big Bore Exhaust for Milwaukee-Eight Softail w/o Factory Bags (Stainless Finish)

The Big Bore by SP Concepts is a full-system 2-into-1 exhaust developed for Harley-Davidson Softail motorcycles that are altered significantly from stock.

Specifically, the system is designed for monoshock Softails without factory hard clamshell bags. Like most 2-into-1 pipes, performance is the reason this exhaust exists. With three-stage stepped head pipes and a short muffler, the Big Bore promotes exhaust velocity. It differentiates itself from the LaneSplitter by featuring a larger diameter muffler with a stepped baffle.

• Fits monoshock Softails without factory bags
• 4 1/2" rolled cone muffler with stepped 2 1/4" to 2 1/2" perforated baffle supports the high exhaust flow of large displacement engines
• .065" stainless steel head pipes step up from 1 3/4" to 1 7/8" and enter the muffler through 2" sections
• Header collars are machined of stainless steel
• Accepts 12mm or 18mm oxygen sensors; adapters included
• Hardware kit includes mount bracket, bolts, speed nuts, and adapters
• This item is for off road use only and may never be installed on vehicles that will be ridden on a public road or highway

The pipe also sheds weight when you remove your factory exhaust. Note the rowdy appearance—the raw stainless will weather and color in the environment in which it's operated, and the hand-TIG-welded sections will prominently display the fact that a little more time went into creating this exhaust than some of the other ones you could buy. 

The exhaust will accept either 12mm or 18mm oxygen sensors; adapters are included so you can use either OE or aftermarket tuning setups. The mounting bracket and hardware are included. Exhaust spring clips are not included; they can be purchased separately.  Exhaust gaskets are not included and should be replaced every time an exhaust system is removed; they also can be purchased separately. 

If you're stuck between this exhaust or a LaneSplitter, your choice really boils down to what modifications you've made or have planned for your bike's engine. The Big Bore supports massive flow when engine RPMs are high, making this exhaust especially suitable for long duration cams that make use of the Milwaukee-Eight's four-valve heads. Stock displacements all the way up to 143" are suitable for the Big Bore. If you're considering aggressive head work, a radical camshaft, or big increases in bore or stroke, the Big Bore will be a good choice.

If you're going to stick mostly with bolt-on engine upgrades to stock engine internals, you may want to look at the LaneSplitter instead; the smaller muffler volume and baffles will help keep your exhaust flowing without giving up bottom-end power.

We are a stocking dealer for SP Concepts. If your order is placed by 2PM EST, it will ship the same day. There's no wait, no drop shipping, and no BS.