MUTHA' THUMPR - Very rough idle, biggest cam for stock heads. Great power above 4900 rpm. Compatible with stock valve springs, benefits from converter & gears, requires cam phaser upgrade & custom tuning.

Ford built a great car in the 2005+ S197 Mustang, but with a little help from COMP Cams it can sound and perform like a real 'hot rod'. The Thumpr Ford 3 Valve Cam Sets for 4.6L/5.4L Modular 3 Valve Engines deliver an aggressive 'thumping' exhaust idle and generous power gains in the middle & upper rpm range. These cams will turn your naturally aspirated or blower-equipped Ford 3 valve engine into a performance machine with a minimum of installation difficulty; only requiring the addition of the COMP Cams Cam Phaser Limiter Kit (#5449) and computer tuning. The COMP Cams Cam Phaser Limiter Kit (#5449) safely modifies the factory variable cam timing (VCT) system allowing for the use of aggressive camshaft lobe technology without sacrificing the benefits of the VCT. Extensive testing of these new camshaft combinations has confirmed repeatable power gains of 25+ rear wheel horsepower with no sacrifices in long term durability.