Is Ur Crank Pulley Worth It
Originally Posted by caelric
Yes, and agree with you that the lightening makes very little difference, on the order of 1 HP in 1st gear.
But we are NOT JUST TALKING ABOUT A LIGHTENED PULLEY.
We are also talking about an underdriven pulley. Caps added for emphasis.
Dave
But we are NOT JUST TALKING ABOUT A LIGHTENED PULLEY.
We are also talking about an underdriven pulley. Caps added for emphasis.
Dave
Only 15-20% of the gains from our pulleys come from underdriving.
People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications we offer use a counterweight as part of the pulley, as these engines are all internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that makes them look similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note in these applications, the elastomer is inadequate in size and durability to act as an effective torsional damper.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that makes them look similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note in these applications, the elastomer is inadequate in size and durability to act as an effective torsional damper.
Hmmm, an aftermarket mod vendor spreading fallacies in the interest of making more money? Never!
But in their defense, I doubt they have anyone on staff that really has a clue about any of that stuff.
But in their defense, I doubt they have anyone on staff that really has a clue about any of that stuff.
Well show us the truth boys, where are is all the VQ destruction you chicken littles are so adamant about. Show us a single crank that flew apart from a undampened NA pulley. Expecting anyone to believe you is like believing in heaven or hell, it's blind faith
That's the basis for all this disagreement. The theoretical problems won't likely show themselves until 100K+ miles and we don't have an abundance of proof one way or the other.
Personally, I see the logic in DaveB's argument and do think it's correct. The fact that so many miles are needed before problems surface is enough for me to see these discussions as academic and generally boiling down to a contest of my theory is right v. show me proof. Without failures to support the argument, it remains theoretical and, therefore, an acceptable risk for those interested in the pulley.
On a related note, rumor has it the old anodized blue units actually improve upon the OEM unit's ability to limit NVH levels and can extend engine life well into the 300K mile range.
Personally, I see the logic in DaveB's argument and do think it's correct. The fact that so many miles are needed before problems surface is enough for me to see these discussions as academic and generally boiling down to a contest of my theory is right v. show me proof. Without failures to support the argument, it remains theoretical and, therefore, an acceptable risk for those interested in the pulley.
On a related note, rumor has it the old anodized blue units actually improve upon the OEM unit's ability to limit NVH levels and can extend engine life well into the 300K mile range.
OK so all the maximas on that other board with plenty of users with 100,000 plus miles....no problems there either. It's possible with extended visits to 7000 rpm or some other high sustained rpm that the lack of dampning may effect some vibrations, which is why I haven't rasied my rev limiter. With an engine as stout as the VQ, I don't know why all the unproven conjecture is taken as gospel. Again....where is the destruction? VQ35's have been around for plenty of time to get this figure out by now
Again, I see the logic in DaveB's contention, but it's not taken as gospel by me. I've never put more than 80K miles on any of my cars, so the long-term effects are pretty irrelevant to me.
That's why I say this whole argument is pretty much an excersise in academic debate. If problems are created but won't show themselves for 200K miles, do you really have anything to be concerned about? Will you make it to 200K miles before having some other serious issue to contend with, possibly resulting from mods that you've done?
The likelihood of having problems and the amount of potential wear-increase seems to have taken a back-seat to who's theoretically right or wrong.
If it creates problems that don't appear until 200K+ miles, then it still (theoretically) creates problems, corrrect? However, if no problems are realized prior to that, then the argument that it's a relatively harmless mod also stands. Both sides could agree that the part might not be as good as the OEM CP but that any related problems would take more miles to discover than the majority of us will put on our G.
Instead, we continue to see the I'm theoretically correct v. Prove it posts. It comes across like a battle of the wills and neither side can offer anything concrete to justify their hard-lined stance.
That's why I say this whole argument is pretty much an excersise in academic debate. If problems are created but won't show themselves for 200K miles, do you really have anything to be concerned about? Will you make it to 200K miles before having some other serious issue to contend with, possibly resulting from mods that you've done?
The likelihood of having problems and the amount of potential wear-increase seems to have taken a back-seat to who's theoretically right or wrong.
If it creates problems that don't appear until 200K+ miles, then it still (theoretically) creates problems, corrrect? However, if no problems are realized prior to that, then the argument that it's a relatively harmless mod also stands. Both sides could agree that the part might not be as good as the OEM CP but that any related problems would take more miles to discover than the majority of us will put on our G.
Instead, we continue to see the I'm theoretically correct v. Prove it posts. It comes across like a battle of the wills and neither side can offer anything concrete to justify their hard-lined stance.
Last edited by GT-Ron; Jan 4, 2006 at 01:22 PM.
Sounds reasonable to me, especially your point about even owning the thing when things go bad, potentially . My point has always been if it's destructive - show me more than theory. Over here in the real world I prove every day that it's not causing any problems. There is still no proof to take one way or the other to end this argument but IMO actually owning it and using it offers a hell of a lot more to chew on the acedemic based or wishful thinking based thoery. I say wishful thinking because I'd guess that 90% of the don't do it camp just want the things to cause catastrophe to show that the side of the camp they joined is correct.
Assume that the pulley is not harmful in any way. It is still about the worst $/hp mod that you can buy. Assuming unorthodox is telling the truth that 85% of the gains come from the lightening alone, that's on the order of $100 / hp in 1st gear, $250 / hp in 2nd gear, $580 / hp in 3rd gear, $1250 / hp in 4th gear, $1750 / hp in 5th gear... (for a 5AT)... Where do I sign??
IM surprised nobody has brought up the topic on what happens in the valve train, and what happens to cam timing and the affects on valve springs with non dampened crank shafts.
Erratic spark timing, and cam timing. The higher the rpms the more important a damper becomes. I understand what the UD pulleys do, I just do not like what they do to my personal car. The loss of flywheel mass and drivability with the UD's is my biggest problem with them.
As power,torque,rpm increases, so does the (crank twisting) harmonics, Not good!
And the firing order on the VQ is not what I would call the best way to balance the crankshaft. All that load starting at front and working its way to the back of the crank. One of the reason's Nissan runs so much oil pressure in the VQ's is to keep the main bearings form taking a beating from the harmonics from the rotating mass. Just my opinion. Fluidamper is the awnser.
Erratic spark timing, and cam timing. The higher the rpms the more important a damper becomes. I understand what the UD pulleys do, I just do not like what they do to my personal car. The loss of flywheel mass and drivability with the UD's is my biggest problem with them.
As power,torque,rpm increases, so does the (crank twisting) harmonics, Not good!
And the firing order on the VQ is not what I would call the best way to balance the crankshaft. All that load starting at front and working its way to the back of the crank. One of the reason's Nissan runs so much oil pressure in the VQ's is to keep the main bearings form taking a beating from the harmonics from the rotating mass. Just my opinion. Fluidamper is the awnser.
Originally Posted by GEE PASTA
IM surprised nobody has brought up the topic on what happens in the valve train, and what happens to cam timing and the affects on valve springs with non dampened crank shafts.
Erratic spark timing, and cam timing. The higher the rpms the more important a damper becomes. I understand what the UD pulleys do, I just do not like what they do to my personal car. The loss of flywheel mass and drivability with the UD's is my biggest problem with them.
As power,torque,rpm increases, so does the (crank twisting) harmonics, Not good!
And the firing order on the VQ is not what I would call the best way to balance the crankshaft. All that load starting at front and working its way to the back of the crank. One of the reason's Nissan runs so much oil pressure in the VQ's is to keep the main bearings form taking a beating from the harmonics from the rotating mass. Just my opinion. Fluidamper is the awnser.
Erratic spark timing, and cam timing. The higher the rpms the more important a damper becomes. I understand what the UD pulleys do, I just do not like what they do to my personal car. The loss of flywheel mass and drivability with the UD's is my biggest problem with them.
As power,torque,rpm increases, so does the (crank twisting) harmonics, Not good!
And the firing order on the VQ is not what I would call the best way to balance the crankshaft. All that load starting at front and working its way to the back of the crank. One of the reason's Nissan runs so much oil pressure in the VQ's is to keep the main bearings form taking a beating from the harmonics from the rotating mass. Just my opinion. Fluidamper is the awnser.
This what I was alluding to when I made my statement about the Nissan teams running fluid-dampers on their RB, SR, and VQ race motors. I'm glad Mr. Pasta posted this.As for damage to the VQ caused by aftermarket pullies, I don't think it will happen. For those that have seen the lower end of a VQ, you'd see where we're coming from. This motor series was built for significantly more power and it's a very robust assembly. When I had my UDP on my VQ30, I ran it from approximately 70K to 105K miles along with lots of 1/4 mile passes plus I had an extended rev limiter to ~7,100rpms (6600rpm stock) which I pushed nearly daily. The VQ can handle not having the damper, but the question is just how benefical it is to power. I'll leave it at that.
I never did think the purpose of the aftermarket CP was for significant HP/TQ gains. Like some other mods, I always thought people installed this to change the driving character, such as an easier-revving assembly... ...simliar to the effects of a lightened flywheel.
Even though a manufacturer may claim a HP/TQ increase, there are items which we all know don't add any significant power yet change the character dramatically. This seems to fall right into that category. Am I missing something? I know a lot of people are caught up in what a part shows on a dyno, but was a power increase from this part really ever expected more than a change in the character of the car?
Even though a manufacturer may claim a HP/TQ increase, there are items which we all know don't add any significant power yet change the character dramatically. This seems to fall right into that category. Am I missing something? I know a lot of people are caught up in what a part shows on a dyno, but was a power increase from this part really ever expected more than a change in the character of the car?
Last edited by GT-Ron; Jan 4, 2006 at 03:59 PM.
I wanted it for a faster launching and quicker revving car. Not for power per se', but to increase performance along with alot of small increases from other mod.
DaveB - very curious about your thought on taking the 3.5 VQ to 7100 without strengthing the internals or removing the UDP?
DaveB - very curious about your thought on taking the 3.5 VQ to 7100 without strengthing the internals or removing the UDP?
Originally Posted by SixFive
I wanted it for a faster launching and quicker revving car. Not for power per se', but to increase performance along with alot of small increases from other mod.
DaveB - very curious about your thought on taking the 3.5 VQ to 7100 without strengthing the internals or removing the UDP?
DaveB - very curious about your thought on taking the 3.5 VQ to 7100 without strengthing the internals or removing the UDP?
Originally Posted by GEE PASTA
IM surprised nobody has brought up the topic on what happens in the valve train, and what happens to cam timing and the affects on valve springs with non dampened crank shafts.
Erratic spark timing, and cam timing. The higher the rpms the more important a damper becomes. I understand what the UD pulleys do, I just do not like what they do to my personal car. The loss of flywheel mass and drivability with the UD's is my biggest problem with them.
As power,torque,rpm increases, so does the (crank twisting) harmonics, Not good!
And the firing order on the VQ is not what I would call the best way to balance the crankshaft. All that load starting at front and working its way to the back of the crank. One of the reason's Nissan runs so much oil pressure in the VQ's is to keep the main bearings form taking a beating from the harmonics from the rotating mass. Just my opinion. Fluidamper is the awnser.
Erratic spark timing, and cam timing. The higher the rpms the more important a damper becomes. I understand what the UD pulleys do, I just do not like what they do to my personal car. The loss of flywheel mass and drivability with the UD's is my biggest problem with them.
As power,torque,rpm increases, so does the (crank twisting) harmonics, Not good!
And the firing order on the VQ is not what I would call the best way to balance the crankshaft. All that load starting at front and working its way to the back of the crank. One of the reason's Nissan runs so much oil pressure in the VQ's is to keep the main bearings form taking a beating from the harmonics from the rotating mass. Just my opinion. Fluidamper is the awnser.
If your car revs quicker in gear, it has to produce more power. And reducing the inertia of your rotating assemblies is only going to increase your likelihood of bogging down on launch. Your beliefs are not congruent.
