I have the UR, seat of the pants feel for sure. There is no absolute answer on this and there never will? Reason? Many reputable tuners say it's ok and run them, other reputable tuners avoid and say not to use. So there is really no way to tell but time. DSM guys have ran them for years and were fine.


1 thing for sure, 10 easy WHP. Better low end too

 

Actually, the only thing that Dave Buschur and Mike from Diamond Star Specialties EVER agreed on was the fact that undamped pullies cause premature engine wear. I'd never run an undamped pully on my car.

 

but just what do you think you are dampening? the Dampener is to dampen excessive harmonic vibrations, but the pulley will only vibrate when the engine is operating at a certain resonate pitch. No has even determine if the pulleys resonate at all.

 

Let's see. Bad engine wear with a solid pulley. No bad engine wear with the stock pulley. Sometimes that is all you need to know.

Oh yeah, what's a balance shaft?

 

Ever look at that stock pully? It has a TINY ruber gasket on it, couldn't possible keep the WHOLE ENTIRE crank in place. Know what I DID notice when I put on my UR pully? More noise, yup, and a slight increase in vibration too, I think it is just there to keep the car more user friendly, there are a lot of things like this to keep out "annoying" vibration

 

Camp Town Races...

I am aware of the entire debate on pulleys, I just thought it was interesting that they offered on for the Subarus and not the Evo.

 

That rubber insert is designed to distribute all that harmonic energy over the entire RPM range. Without it, you'd see a bit spike in angular crankshaft twist at one particular engine speed. You might only feel a bit more NVH but that's not to say that what you are doing is okay to the motor.

We did harmonic testing on Subaru motors before we released our UD pulley. We haven't done the same with the EVO but considering that it's a inline four, I'd be pretty carefull when playing with aftermarket pulleys.

My 2c,
shiv

 

Thanks Shiv