A harmonic balancer isnt required for the VG30DETT. Unless used in Higher HP applications perhaps. However a Crankshaft Pulley on the other hand is required. And It would be much cheaper for nissan to make them out of steal with a rubber ring than it would be for them to make individual billet cut aluminum UDP's
That does sound interesting but the fact remains that there is still a vibration present and the only components left to absorb the vibration is the drive line, crank and any accessories run off the crank. Joe
If you purchased the full service kit and the UDP from Caz then i'm sure she will supply the correct size belts. Last time I was at her place she showed me her belt size charts and what ones are specified for stock balancer and the GFB one, so she knows what's what and I wouldn't worry if I was you. Ben
True. Then you need to consider how much of that vibration is absorbed by a single rubber ring. I'm highly doubtful that the rubber ring absorbs all of the vibration.. especially since the vibration already made is amplified by the heavy stock pulley... then absorbed by the rubber ring. In the case of the UDP. Being smaller and lightweight it keeps the vibration tame. Not needing to have a rubber ring to absorb the vibration. Also not exciting the vibration as much as the heavy stock pulley. So in the end it would come down to which exerts more vibration on the drive line, crank and accessories. That'd be interesting to know.
Its not that its a large vibration but the amount of pulses, so a constant minor vibration may cause a fatigue failure in a component. Although when its all said and done put it on and if you don't like the results take it off and sell it. Joe
I think either way. There will always be vibration made from both stock and aftermarket pulleys, but I don't believe either is enough to stuff things up. On the occasion where things have stuffed up, it may have been because people have used cheap pulleys
Knowing Caz, if you purchased a 100K kit that would have normally came with belts then she would have put in the correct belts to suit the UDP. She's pretty sharp with supplying what you need
the extra responce of fitting a udp might put more strain on the engine mounts so that might be the cause of vibrations that some people expirience if the engine mounts are old and soft ? just a thought
There is no rubber on my 4AGE pulley, and that thing revs to 8000rpm stock and has a crank of similar length to the VG. Plenty of other cars don't have the rubber, new Golf's IIRC too. No more than adding 5hp any other way... I had a Unorthodox racing one on my NA. Bought it second hand off a guy who took it off due to vibration. I never had a hassle with it.
Since i'm in the process of doing an engine swap, I'll need to buy new engine mounts, or reuse old ones that are in good condition. So this should eliminate that as a possible cause I would imagine.
Maybe people are just installing them dodgy or something?... I would think people's mechanical skill would be more to blame than a perfectly balanced billet cut aluminum UDP..
If someone can find an example of an "expertly installed UDP." that has caused damage. Then i'll believe they are not worth using.
The fact remains the Z32 does have a harmonic balancer fitted at the factory. Harmonic balancer From Wikipedia, the free encyclopedia This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2008) 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. 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. Certain cars, however, do not come equipped with an external balancer on the crank pulley, and as such, can have the pulley replaced with a performance oriented product which counter-act these resonance frequencies.
Yeah I already knew what a Harmonic Balancer was. There are different kinds of engines that require a harmonic balancer, as well as engines that do not require it. Consequently companies such as GFB do not make UDP's for skylines for that exact reason. Because skylines require a harmonic balancer. a 300zx on the other hand does not. Here's something for you to read. "When looking at high performance engines such as those found in Honda VTEC equipped cars and the S2000, it is obvious that manufacturers do understand the benefits of reducing engine inertia, and have utilized lightweight pulleys to help the power output and responsiveness without the use of a harmonic balancer. However, this is not the case for all engines, many of them do require the use of the harmonic balancer to prevent failure. Skylines with the RB20, 25 and 26 are a good example of this, which is why we don't make a pulley kit for them. The pulley kits we do make are for engines that do not rely on the balancer to any significant degree."
Lets keep away from Wiki quotes shall we... Show me a broken VG that was caused by an ally UDP. Not some mental 1000hp thing either, a normal boosted TT or NA. I did 30k+ with mine and had no issues, and I was revving the tits off that every friday night up the mountains. Karl has 300rwkw+ for a few years and has had no issues .
The replies were in response to your original question "Why not get an UDP?" Perhaps interesting reading, if the subject was about Hondas.
The replies were all good. I didn't start this thread for arguments sake. Just a good debate backed by various opinions. Because of this debating I've learned a hell of a lot more about Pulleys than I had known this morning. In regards to Hondas.. well Engines aren't unique to Hondas. All cars have engines. So I think that this is all interesting reading, regardless of what your car is or not. Point to take in was that different engines require different things and to know whether or not UDP's are suited to your kind of engine or not. In our case this is all relevant to the VG30DETT.
Vibration, UAS did a lot of testing in this subject, put me off it completely from his experience, a selected added few also on top of this, but then a lot of people have not had a problem also (but it can go undetected also) so meh, personally I didn't wanna risk it after shit just goes wrong in general why add another risk too it.
