Select the vehicle you are shopping for:





My Garage:

Billy Boat Performance Mufflers - Sport Sound

This part is model specific. Please select a vehicle above to ensure that you get the correct part.
Billy Boat Performance Mufflers - Sport Sound

PART#: BB335E90S

BRAND: Billy Boat Performance

Be the first to review this product

$930.95 / each

Typically ships in 2-3 weeks

Shipping exception – charges apply


Reduced backpressure gives your BMW an instant horsepower boost! The stock BMW muffler has a vacuum-activated butterfly valve on the driver's side muffler. This valve is closed under most conditions, diverting all exhaust gases to the passenger's side. Under certain conditions (e.g. high throttle/low vacuum), the butterfly valve opens so two mufflers can be used. The Sport version of our Tri Flo exhaust eliminates the actuator and butterfly valve so both exhausts are used all the time. The result is an increase in horsepower and a more aggressive sound that announces your performance upgrade to anyone within earshot. (For a more refined growl, consider the Touring version of this exhaust, which uses a vacuum-activated valve just like the stock exhaust.) Stainless steel construction. Limited lifetime warranty. Simple Cut/Clamp installation. Includes left and right mufflers.

Brand Description

Since 1989, Billy Boat Performance Exhaust systems have incorporated 3-generations of fabrication skill and racing talent inherited from the Boat Family. B&B starts with T-304 stainless steel known throughout the industry as the highest quality material practical for automotive exhaust applications. All exhaust tubing is mandrel bent on sophisticated CNC machinery for precise fit and uninterrupted exhaust flow. What's more, the use of T-304 stainless steel flanges offers precision fit and complete resistance to harsh elements. All hangers, resonators and tips are T-304 stainless steel as well. Every muffler is built in-house with years of racing and street development invested into its design. Each muffler is tuned to match its application for the best possible performance gain and sound quality combination. Stress relieved end plates, gussets and TIG welding ensures awesome strength and rugged durability.


Billy Boat Performance Exhaust offers a Limited Lifetime Warranty to the original purchaser of all non-race application products. Said products are warranted for life against corrosion and two years against any defect in workmanship and materials.

Claimed defective products must be returned with a Returned Goods Authorization number to Billy Boat Performance Exhaust at the buyer's expense. Products returned without an RGA number are subject to refusal. Upon receipt Billy Boat Performance Exhaust will, at its option, repair or replace the defective item. Damages caused by abuse, racing or alteration are not covered under warranty.

Our products are meant for high performance use and may not be legal for highway use in some states. Sound quality is subjective and may not be covered under warranty. The warranty set above is the only warranty, expressed or implied. In no event will Billy Boat Performance Exhaust be responsible for any consequential or incidental damages or charges.

Diff Qty Sell


Write Your Own Review

You're reviewing: Billy Boat Performance Mufflers - Sport Sound

How do you rate this product? *

1 1 star
2 2 star
3 3 star
4 4 star
5 5 star