Dinan's Free Flow Exhaust for 645 models provides improved flow and the resulting power gains without the excessive noise and ''boominess'' associated with typical after-market mufflers. The mufflers feature ridged and durable cases, manufactured from 100% 20 gauge-304 stainless steel inside and out for optimum resistance to corrosion. Internally, the systems feature Dinan's Tuned Resonance Chamber Technology, providing the optimum balance between maximum power gains and a civilized, yet sporty exhaust note. 3.5 inch diameter polished stainless tips give the cars a tasteful performance look as well.

Features:

• +6 HP @ 6600 RPM, +5 lb/ft @ 6600 RPM
• Uses the factory brackets and hangers for a factory-like fitment
• Weight Savings
• Dinan's Tuned Resonance Chamber Technology
• 100% 304 stainless steel construction
• 3.5" laser engraved polished stainless steel exhaust tips

VEHICLE FITMENT

• 2004-2005 E63 / E64 BMW 645Ci - N62 4.4L