Originally posted by Dude:
Originally posted by PA 3L SVT:
[b]UDP bad. DMD good.
[/b]Long story short: A UDP without any damper (like all of them) allow the crank to vibrate leading to bearing wear, etc. The DMD (Dual Mode Damper) has 2 dampers to reduce/eliminate the vibrations at two frequencies. It's a Ford OEM upgrade found on European Duratecs. The stock pulley has one damper (which is better than none, but not optimal for an engine that revs to 7k).
I'm quite convinced that my STOCK motor died as the result of "crank harmonics (vibrations)" thrashing a bearing. It won't blow up in a day, but long term prognosis could be bad.
Ford spent a lot of money to develop the DMD. It also took a lot of convincing for the accountants to put a more expensive part on the Euro Duratec, especially one that the marketing guys really can't show off. It's also the only thing Ford has done to combat the early deaths of 2.5 Duratecs (and only in Europe to boot).
Search around for the discussions (ad nauseum) on the DMD. They'll contain a link somewhere to a site that details the detriments of UDPs on a Toyota (?) engine.
On topic: I might go to the Friday Test and Tune (9-4) at Maple Grove next weekend. $25 and the crowds should be low as many people actually have jobs to be at then.
http://www.maplegroveraceway.com/fmsninfo02.htm
