Repostez aici un mesaj pe care l-am pus si pe seatcupra.net in speranta ca putem afla mai multe de la cineva cu cunostinte ingineresti mai bogate
Crankshaft pulley is iron, weighs about 1.6kg (~3.5lbs) and according to people around the net it does incorporate a rubber harmonic damper.
This is how it looks (a Golf Mk4 version but still a 1.8T):
I for one fail to see the rubber ring which would do the harmonic balancer job...
This is a damaged one from a longitudinal 1.8T (an A4) and the rubber ring can be seen:
Lightweight (not underdrive!) aluminium pulleys from ECS, Craven or other manufacturer. They do not incorporate a rubber harmonic balancer and weigh around 0.3-0.4 kg (0.66-0.88 lbs)
Fluidampr viscous-damping pulley from Fluidampr. This is how it works:
The 1.8T version weighs 6 lbs or 2.7 kg
From reviews we find out also that Fluidampr dampens the vibrations and helps the smoothness when revving up under open throttle almost to Rolls-Royce levels, or at least this is how it performed on large V6s and V8s.
On the other side, for torquey engines like a chipped 1.8T there is said lightweight pulleys are not suitable, the crankshaft twist would quickly wear out the bearings and previous to that engine smooth running would suffer.
However, Fluidampr is heavy, 70% heavier than stock pulley. The basic idea behind lightweight pulleys was to free horsepower wasted by parasitic drag.
Will a Fluidampr decrease available crank hp and by how much?
Will a lightweight pulley provide a couple more hp and by how much?
Or crank hp would not be affected enough to feel the difference?
I'm talking first and fore most to people who had tried at least one of them or they are skilled in engineering or both. Balancing a high-revving engine is a very delicate job subject to great risks.