Nissan 370Z Forum - View Single Post - GTM Performance Engineering: VQ37VHR Engine Build 700HP Power Package

conmam · 09-06-2012, 03:19 AM

Quote:

Originally Posted by Jordo!

Hmm.

I I have to agree that replacing the factory harmonic balancer with an aftermarket lighter pulley will pose an incredible risk of killing your engine.

We are talking about a total engine eradication just like what you saw on the photos that Sam posted. This looks so much like what happened to my friend 9 years ago on his BMW 328 with the E36 motor series ( Inline 6 in this case ).

As we all know, the popular method for making power pulleys on E36 engines is by removing the harmonic damper and replacing it with an underdrive lightweight alloy assembly. This is a VERY dangerous product because this stock damper is essential to the longevity of an engine. The substitution of this part often results in severe engine damage.
It is also important to understand that while the engine in a BMW is designed by a team of qualified engineers who understood the engine characteristics inside and out, these aftermarket power pulleys are created by the people who do not understand many of the very important principles of physics.

To put things simple, it is not the underdrive feature that kills the engine, but rather the lack of dampening the harmonic vibration that the crankshaft generates every time after each cylinder firing sequence. When this sinusoidal harmonic vibration coincide with the phase vector of the engine RPM, resonance frequency will occur. When this occurs, it must be counterbalance immediately and that is the exact job of the harmonic balancer pulley. If not, the power under the sine curve will keep on increasing or accumulate exponentially and that will guarantee to destroy the entire engine and the possible surroundings, such as the starter in this case of this VQ37VHR engine.......

Think 5 times BEFORE you put in an underdrive aftermarket pulley. The risk is 1000 times the reward.... Not worth it at all......