Shopping Cart

Your cart is currently empty.

ApexBuilt® BMW G80 M3 & G82 M4 S58 High-Flow Catted Downpipes (2021+)

Sale price $3,512.00 Regular price $2,992.00

ApexBuilt® G8X M3/M4 HFC Downpipes offer...

• No check engine light on factory-tuned vehicles.

• 50 state emissions legal

• Industry-leading build quality.

• Perfect fitment, guaranteed.

• Drastically improved throttle response, quicker turbo spool, and an aggressive exhaust note versus OEM.

• Estimated gains of 20-25+ wheel horsepower and 40-50+ TQ when installed on a vehicle that is not tuned.

• Estimated gains of 45+ HP and 60+ TQ over stock power levels when paired with an aftermarket ECU tune.

• TIG-welded T304 stainless steel construction, assembled by hand in Naples FL.

• GESI GEN1 UHO metal-core 300cpsi 4.5" cats, rated for 500-800hp applications. 

• Lifetime warranty.


These these parts are for OFF ROAD / RACE USE ONLY. We advise you to run a tune on your vehicle for best results.

Read more about GESI cats:



Based on 2 reviews Write a review