Im going to put mine on tonight. Ill post results. My butt dyno is pretty accurate. I drive the car 500 miles a week and I get on it a lot

 

You're not going to see problems in a few months. It just adds more wear if you didnt have them over x amoutn of time. What that really means? Who knows. 5 thousand less miles? 8? 12?

 

8 months, 12k miles, no problems

 

The best people to talk to about this is probably someone who builds motors.

 

I did not mean I was going to post problems tonight, I was going to post if I felt any gains worth mentioning. If I dont... its coming off!

 

I went through a lot of pulley talk on bimmer forums a little while back. I read up on them and i ended up putting one on my e36 M3. The damage you can sustain is from harmonic amplification of the imbalance of the drive shaft. The thing is is, that this happens at a very narrow (maybe even a single RPM) part of the revband. So for that type of damage you have to be at that rpm for a good long while. If anyone has seen a physics teacher shatter a wine glass by finding the frequency, it takes a bit of time for the harmonic amplification to get to the point where it can break the glass. However, there is a good deal of wobbling the glass will go through. It seems however, that simply by replacing the crank pulley doesnt cause enough damage to break anything. Most of the bimmer guys' experience was with snapping drive shafts. However, the crank pulley was used in conjuncture with lightened flywheels as well. It was determined that FOR SURE that crank pulley's were NOT to be used with lightened flywheels. (however, some unorthodox released a LFW that was supposed to work with a lightened crank pulley) There were still doubters that didnt want to put on a potentially dangerous part (with good reason, cars are expensive investments)
For what it's worth, I had my crank pulley on my M3 and felt VAST differences. Best add-on that i put on my car. Dont be fooled by the numbers, the driving feel and response changed dramatically. The car jsut felt like it really wanted to run after the pulley.

Anyway, its all gonna come down to whether or not you want to take the risk with this part. I just though i'd pass on some info that i got along my way. I personally put it on because in my opinion, the risk was low because the engine would go up and down in revs so it wouldnt stay long enough in the harmonic amplification range to do any real damage. Again, no one can tell you for sure whether or not you should be able to do something or not. Every car is different and its best that you learn for yourself.

All in all, its all about how enjoying your car. And ofcourse, to each his/her own.

 

ahh.. this is the best opinion yet! Truely, no one else has brought up the fact that only at a certain pitch would the pulley cause a problem untill now.

 

BMW motors are a bit different, it takes much more to damage a 4 cylinder crank shaft, then a 6 cylinder one.

 

OK NM on the install. Perrin make some shotty **** as far as I can see. The pulley was running up against the timing cover because of the design. Also, it has no timing mark. **** it, Ill keep stock one on.

 

wow really? i thot they would have at least addressed the timing mark... but shewt... if it's rubbing that's all bad... so many different manufacturers of these things tho... unorthodox, authority and perrin... i think they're all on the cheap scale tho... cept maybe unorthodox...

 

More than a year on the car - not a problem. Same with other customers.

 

How many pulley sets have you installed in on customers cars? Were they full sets or just crank pulleys?

 

Will someone just please Balance Check the Crank Pulley for vibrations this will solve most skeptism

 

My UR pulley has timing marks and doesn't hit the timing cover....

 

It was Andrew's idea to get the Perrin