$595.00 USD
$595.00 USD








Get that aggressive and sharp BMW sound without any check engine lights or in cabin drone. The Supersport X-Pipe Valvetronic exhaust slip on system includes Fabspeed's high-performance Valvetronic axle back section and the "Double-X" maxflo mid-pipe for the perfect combination of sound, power, and weight reduction.
SOUND:
This system transforms the M3/M4 into a proper sounding sports car. You’ll actually hear a lot more turbo spool when letting off the throttle and you’ll feel the gritty iconic BMW straight six sound coming through the cabin under hard acceleration. Adding more pops and bangs on downshifts and giving a throaty rumble at idle.
POWER:
On our in-house DynoJet, this system made max gains of 25 ft/lbs of TQ at 3,300 RPM and 22 WHP at 5,500 RPM. That’s 26 crank HP! Take a look at our dyno graph and you can see that power is gained throughout the entire power band.
FEATURES:
DISCLAIMER: This product removes the OEM catalytic converters from the vehicle, and as such, is strictly intended for closed track events and off-road use only, never to be driven on public roads. This product is or contains a Racing Cat Bypass Pipe, which will give you check engine lights on OBD2 cars. We suggest pairing this product with racing software to prevent fault codes and check engine lights. Racing Cat Bypass Pipes are solely intended for track and race cars as they are NOT California Air Resources Board Certified (CARB) and not EPA certified. You are hereby informed and warned to check your local, state, and federal laws before buying and installing these or any aftermarket parts to be sure whether usage is in violation. All installation-risk and use-risk is borne by the end-user and installer of these parts.
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$595.00 USD
$595.00 USD
This product can expose you to chemicals such as lead and lead compounds, which are known to the State of California to cause cancer or birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.
For a complete list of chemicals known to cause harm, visit https://www.p65warnings.ca.gov/chemicals.
Under the federal Clean Air Act (42 U.S.C. §7522(a)(3)), it is illegal to manufacture, sell, install, or use any part that defeats or alters a motor vehicle’s emission control system for use on public roads. Unless a product has received an Executive Order (EO) from the California Air Resources Board (CARB), it is not legal for use or installation on any pollution-controlled vehicle driven on public highways.
Some states have CARB-equivalent or independent emissions laws. Customers are responsible for verifying local regulations before purchasing or installing emissions-related products.
All performance, racing, or competition parts sold by this company are intended solely for off-road, closed-course, or competition use on vehicles that are never registered or used on public highways.
Kies Motorsports, LLC sells and markets these products for lawful use only. We do not condone or authorize the use of emission-control defeat devices or any modification that violates the Clean Air Act or state regulations.