Hi Striped SVT,
Here is an excerpt taken from a Toyota Supra site. It pretty much sums up the how and why of dual mode dampeners...most folks here feel there definitely is a need for it, in light of the fact, Ford has taken the time and money to develop it and place it as standard equipment on new Mondeos. The folks who have installed it notice a bit smoother operation...must be good!
Besides bottom-end internal balance, the flywheel has the greatest effect on engine longevity [source: Advanced Engine Technology, written by Heinz Heisler]. Toyota uses the term, "dual-mode damper" for the crankshaft pulley. It's effects on the crankshaft are twofold- the dual-mode dampers' inner ring counteracts torsional vibration, while the outer ring counteracts bending vibration. Inner/Outer rings, hence the 'dual-mode' terminology [source: Toyota Engine Technology]. Perhaps of some significance w/regard to the dual-mode damper, is mention of design parameters meant to deal specifically w/400Hz harmonics. Whether or not the Supra [or any] flywheel is likely to serve this specific function, could not be found in the literature mentioned. The aforementioned frequency [400Hz] is quite possibly the resonant frequency of the engine, so that aspect of vibration attenuation could be surmised as simple noise reduction- this a best guess on my part only. They can be gotten from Mr Haines for $130.58 check or money order only ( I'm his new sales rep J/K
) Pics of the installation can be seen here...
DMD Pictorial You will like it...Ed
