2009 NISSAN 370Z 7 SPEED AT
-GTM STAGE 2 SC KIT TURN KEY
-GREDDY TIC CAT BACK AND TEST PIPES
-Due to time restraint no oil cooler were installed
DYNO RESULTS
PICS OF THE CAR
UNDERDRIVE PULLEY is a bad idea all the way around for few reasons :
- Despite what anyone says about this engine being internally balance and removing the harmonic balancer does not have any effect on this engine is totally false. So by removing the harmonic balancer (witch is made from two part metal and rubber in the middle bonding them together for the sole purpose of absorbing engine harmonics and vibrations ) you are destroying your engine .
- Further more by installing the lighter aluminum pulley, keep in mind that aluminum is softer then harden steel (crankshaft) you are also taking a chance of either killing your crankshaft or being unable to ever remove the underdrive pulley sense with time it will weld it self to the crank. and here is exactly what happened in this case, So we had to remove the whole front end, radiator support, a/c condenser so we can put a big enough air gun to brake loos the bolt and still had hell of time to do so .
Also I'm quoting the same info from the web
Quote:
From Wikipedia, the free encyclopedia
A harmonic balancer (also called crank pulley damper, crankshaft damper, torsional damper, or vibration damper) is a device connected to the crankshaft of an engine to reduce torsional vibration and serves as a pulley for drive belts.[1][2]
Every time the cylinders fire, torque is imparted to the crankshaft. The crankshaft deflects under this torque, which sets up vibrations when the torque is released. At certain engine speeds the torques imparted by the cylinders are in synch with the vibrations in the crankshaft, which results in a phenomenon called resonance. This resonance causes stress beyond what the crankshaft can withstand, resulting in crankshaft failure.
To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft. The damper is composed of two elements: a mass and an energy dissipating element. The mass resists the acceleration of the vibration and the energy dissipating (rubber/clutch/fluid) element absorbs the vibrations.
Additionally the energy transferred from the piston to the crankshaft can induce as much as 2 degrees of twist in the crankshaft, which has many follow-on effects on all engine elements that require adequate timing such as valve opening, cam timing, ignition timing etc.
Over time, the energy dissipating (rubber/clutch/fluid) element can deteriorate from age, heat, cold, or exposure to oil or chemicals. Unless rebuilt or replaced, this can cause the crankshaft to develop cracks, resulting in crankshaft failure.
Performance enthusiasts have been known to remove harmonic balancers, usually when the balancer is attached to the crank pulley, deciding that they aren't necessary and their mass reduces the performance of the engine. However, this is unproven and potentially very risky because the danger of damage to the engine from the vibrations the damper is intended to prevent is too high.
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