Interesting Article about Power Pulleys written by Steve Dinan
I just saw an article on Dinan's website called "The Danger of Power Pulleys & Understanding the Harmonic Damper." This is the first I have read about the potential problems with power pulleys. The article by Steve Dinan is well written and has a lot of supporting data. Here is a direct link:
i believe steve dinan wrote this white paper quite a while ago. all the science seems sound. i checked and evosports power pullies do not modify the harmonic dampener (or the crankshaft pulley, i think?) so they should be safe.
Sorry Daniel, but this is old news. Steve has been trying to discredit UD pulleys for years.
BTW, the failures of the crankshafts on ERT pulleys were caused by crankshaft pulley being too shallow. It allowed crankshaft bolt to bottom out in the threads. As a result, the snout of the crankshaft would crack from TQ being applied to it by air gun when the bolt bottomed out, leading to eventual crank failure.
It had nothing to do with lack of damper. The damper is actually meant to dampen accessories belt noise, not crank vibrations.
Our UD pulleys replace Water Pump, Power Steering, Crankshaft and Alternator pulleys.
S62 actually has a real damper (Item 1) that is behind crankshaft pulley:
Here are dyno results:
Last edited by vadim @ evosport; 12th November 2003 at 07:41.
m I think it sounds resonable. I'm not sure I ever thought that changing pulleys was suitable to my type of mods..
I like sexy mods... Thow a couple of babes on the packaging, and I'll buy anything...
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Originally posted by vadim @ evosport Sorry Daniel, but this is old news. Steve has been trying to discredit UD pulleys for years.
The dyno results and customer feedback have clearly shown that the UD pulleys are a good mod. I don't like that the cabin lights dim here and there, but that is a relatively minor annoyance.
It is just interesting to read what a major BMW tuner, such as Dinan, has to say about this type of modification.
Originally posted by BeastPower The dyno results and customer feedback have clearly shown that the UD pulleys are a good mod. I don't like that the cabin lights dim here and there, but that is a relatively minor annoyance.
There are 2 customers experiencing minor dimming of their interior lights. This is due to faulty alternators, which are producing less power than normal. The UD pulleys are simply making these issues known. We have several M5 pulley owners, with various years of production, all having no issues.
Quote:
Originally posted by BeastPower It is just interesting to read what a major BMW tuner, such as Dinan, has to say about this type of modification..
In all actuality, Dinan has said nothing about any of our pulley kits as they all leave the harmonic dampener untouched.
I didn't read Dinan's paper on this, but I can add that UD pulleys and certain other mods used together will cause catastophic failures. For example: on an E36 M3 (not sure about other models) if you run UD pulleys and a light flywheel you will be replacing your engine after a few thousand miles. Didn't happen on mine, but I'm friends with two guys who had this problem on E36 M3s.
BTW, the failures of the crankshafts on ERT pulleys were caused by crankshaft pulley being too shallow. It allowed crankshaft bolt to bottom out in the threads. As a result, the snout of the crankshaft would crack from TQ being applied to it by air gun when the bolt bottomed out, leading to eventual crank failure.
Flywheel has nothing to do with this. This is a very common "urban myth" story among BMW enthusiasts.
Originally posted by Lincoln I didn't read Dinan's paper on this, but I can add that UD pulleys and certain other mods used together will cause catastophic failures. For example: on an E36 M3 (not sure about other models) if you run UD pulleys and a light flywheel you will be replacing your engine after a few thousand miles. Didn't happen on mine, but I'm friends with two guys who had this problem on E36 M3s.
This is only half the story. This is the case with kits on the 6cyl BMW's using a LTW flywheel and a CRANK pulley. This motor is susceptable due to the length of the block and the fact that it is an in-line motors. "V" motors do not have this issue. Also, even on the M50/52 motors, we chose not to use the crank pulley, but I know many people that both have and have nto had problems. It is not a given, but a possibility. We chose not to even have a possible problem and not make the crank pulley.
Interesting Article about Power Pulleys written by Steve Dinan
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