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G6 GTP: "Not a Corvette or Porsche, but pretty darned close"

28K views 314 replies 154 participants last post by  laphan  
Re: Test Drive: 2006 Pontiac G6 GTP Coupe

Carver said:
Ugh, another OHC kool-aid drinker. The V6s in the G6 are not simply bored out from any older engine. The 3500 is a greatly refined and modified evolution of an engine dating from the 80s. The NVH levels are good, so good that it doesn't need NVH-fighting shafts. \
The 60 degree engine family has never had or needed balance shafts. Balance shafts are used in engines that are not primarily balanced (for example, 90 degree V6s like the 3800). The shafts, driven off the crank, basically create an equal but opposite "inbalance" than cancels out the primary vibration and greatly improves the engines smoothness.

Since 60 degree V6s are already primary balanced, balance shafts are useless.

Reviews of the revised 60 degree family do seem to back up your observation that they are much better in terms of NVH.