2007 Chevy Cobalt

Gains with the GMPP exhaust were modest, yielding only 1.2 hp and 1.3 lb-ft at the tires (red graph). We're not sure what to make of the richer AFR experienced after the exhaust installation and are probably more willing to chalk it up to variations in how we had our wideband 02 secured into the tailpipe (the slippery finish of our stock and GMPP tips meant that it blew out a couple of times and actually ended up being held by hand-with gloves of course). Apparently, the stock exhaust proves just about adequate for the needs of the factory 2.4L. Not all improvements are dyno-measurable, however, as the GMPP exhaust enhances sound, improves appearance, and gets us ready for flow needs we'll be growing into big time in an upcoming issue ...

2007 Chevy Cobalt - Practically Powerful

Gains with the GMPP exhaust were modest, yielding only 1.2 hp and 1.3 lb-ft at the tires (red graph). We're not sure what to make of the richer AFR experienced after the exhaust installation and are probably more willing to chalk it up to variations in how we had our wideband 02 secured into the tailpipe (the slippery finish of our stock and GMPP tips meant that it blew out a couple of times and actually ended up being held by hand-with gloves of course). Apparently, the stock exhaust proves just about adequate for the needs of the factory 2.4L. Not all improvements are dyno-measurable, however, as the GMPP exhaust enhances sound, improves appearance, and gets us ready for flow needs we'll be growing into big time in an upcoming issue ... View Related Article

2007 Chevy Cobalt

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