Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Underdrive pullies for 2.5L Duratech.

I know this subject had been hugely debated on here in the past. But, I haven't visited CEG in several months. Last year, I was considering installing the SHO Shop U/D pullies. Several people warned me not to. Their reasoning was that the stock crank pulley acted as a harmonic balancer/damper. The U/D crank pulley was solid aluminum. It would eventually cause catastrophic engine failure. Since then, I called SVT and asked them about this. Their answer was interesting. They said that the stock crank pulley on the 2.5L Duratech was NOT a balancer/damper. They said the Duratech engine was internally balanced. However, they also said that they could not recommend changing pulley ratios from stock. This was due to liability reasons for possible overheating and low battery charging. I've decided to get the SHO Shop pulleys. They include an aluminum crank and power steering pulley w/shorter belt. I'm also going to get a stock size aluminum alt. pulley from ASP. The lighter rotational mass of the aluminum as well as the smaller crank pulley size is going to be good for at least 6 HP and 8-9 ft lbs torque at the wheels. I'll post dyno results before and after the pulley swap.