UR Crank Pulley: The Final Word
#106
Originally Posted by Hydrazine
Now my next question is about the lightened flywheels and clutch. By going with a Tilton Clutch and Flywheel you cut out about 60 lbs of spinning bull sh*t.
If you think the pully makes a difference check this out. It's freakin awesome.
http://www.350zmotoring.com/forums/s...ghlight=tilton
http://www.350zmotoring.com/forums/s...threadid=18641
You've got to see the video!
I really want one of these bad boys. These make pullys look like mothers milk. Is it trashing the engine??? Probably, but either way it sure looks like major fun.
If you think the pully makes a difference check this out. It's freakin awesome.
http://www.350zmotoring.com/forums/s...ghlight=tilton
http://www.350zmotoring.com/forums/s...threadid=18641
You've got to see the video!
I really want one of these bad boys. These make pullys look like mothers milk. Is it trashing the engine??? Probably, but either way it sure looks like major fun.
#108
Former G35driver Vendor
iTrader: (23)
Joined: Jul 2004
Posts: 3,054
Likes: 85
From: Los Angeles California
Originally Posted by al503
For our purposes, we've been debating how far the rubber actually goes through the pulley. My position is that it is slightly recessed into the pulley while others have argued that it goes almost completely through the pulley.
Originally Posted by al503
Now that we have someone graciously willing to part with a pulley, and someone willing to pay for shipping and a 6-pack (non-company business) for a shop guy to cut it for me, we'll know the answer soon enough.
Originally Posted by al503
If the rubber is just slightly recessed on the surface, it can't do that much damping. If it goes almost through the entire pulley, then obviously, it would have much greater dampening ability.
Originally Posted by al503
All other things being equal, I would think that the dampening ability of a particular part would be dictated by 2 things:
1. how much of the part is comprised of the dampening material, be it rubber, asphalt, etc and,
2. how the aforesaid dampening material is integrated into the part. Put another way, the rubber would be more effective if it were pressed between the metal versus just being on the surface of the part.
1. how much of the part is comprised of the dampening material, be it rubber, asphalt, etc and,
2. how the aforesaid dampening material is integrated into the part. Put another way, the rubber would be more effective if it were pressed between the metal versus just being on the surface of the part.
If the Nissan engineers analysis indicated to them they needed a rubber band glued to their damping pully, should we assume your professional analysis to be more valid?
Your arguments appear more entrenched than objective.
Last edited by Hydrazine; 12-28-2004 at 11:07 PM.
#109
Former G35driver Vendor
iTrader: (23)
Joined: Jul 2004
Posts: 3,054
Likes: 85
From: Los Angeles California
Originally Posted by DaveB
I think those guys are clueless to how much a flywheel should be lightened. .... Light flywheels are great for road course racing where the motor spends it's time in upper rpms and the driver is good at rev matching (as the author of 350Z post says).
Makes me think a diametric design could be utilized for drag racing. A very heavy flywheel or even a momentum wheel spinning at redline RPM could be a good way to store a lot of energy before launch.
#110
Damn Hydrazine, don't be so hard on poor ol Al. I've almost got him ready to buy my plastic/cardboard overdrive pulley and Ionalyzer intake system.
right you are guys, small displacement engines for drag racing- high mass fly wheel (or high stall converter) for energy storage, long tube smaller diameter headers, long collector, and high gear ratio. large displacement can live with smaller flywheel, same or larger diameter headers and short collector and less rear ratio.Road racing is generally (but not always) the opposite for rapid response to RPM, inertia changes. Note I left out the pulleys? Either can be tough to live with on the street when carried to extremes as are all true race cars.
right you are guys, small displacement engines for drag racing- high mass fly wheel (or high stall converter) for energy storage, long tube smaller diameter headers, long collector, and high gear ratio. large displacement can live with smaller flywheel, same or larger diameter headers and short collector and less rear ratio.Road racing is generally (but not always) the opposite for rapid response to RPM, inertia changes. Note I left out the pulleys? Either can be tough to live with on the street when carried to extremes as are all true race cars.
Last edited by jcv; 12-29-2004 at 12:04 AM.
#111
For those interested in how elastomers (rubber) can dampen or isolate engines you can check out a simplified discussion here;
http://www.earsc.com/HOME/engineerin...dex.asp?SID=61
Ballistic shocks are a whole nother matter!
http://www.earsc.com/HOME/engineerin...dex.asp?SID=61
Ballistic shocks are a whole nother matter!
Last edited by jcv; 12-29-2004 at 12:11 AM.
#112
Originally Posted by jcv
Damn Hydrazine, don't be so hard on poor ol Al. I've almost got him ready to buy my plastic/cardboard overdrive pulley and Ionalyzer intake system.
#115
#116
Originally Posted by Hydrazine
How far the rubber goes is only a tangent but you can convince yourself of anything you want.
You are in no position to make such a technical judgment. And your first reaction will be "but neither are you!" And my response is yes I am, I have performed shock and vibration testing/analysis/qualification on several components over the years and have a good understanding of the subject. This comes through first hand experience.
You left out one very important detail. #3. Mass/momentum. If you change the mass or momentum of the pully you change the resonance frequency/amplitude of the crank and its natural damping factor. (with or without damping materials such as rubber.)
Your arguments appear more entrenched than objective.
#118
Originally Posted by jcv
right you are guys, small displacement engines for drag racing- high mass fly wheel (or high stall converter) for energy storage, long tube smaller diameter headers, long collector, and high gear ratio. large displacement can live with smaller flywheel, same or larger diameter headers and short collector and less rear ratio.Road racing is generally (but not always) the opposite for rapid response to RPM, inertia changes. Note I left out the pulleys? Either can be tough to live with on the street when carried to extremes as are all true race cars.
#119
Thanks for all the great info. My only concerns are:
1. Does it bogg down the engine at all?
2. Is it easier now to stall with the UR pulleys on?
3. Does the rpm fluctuate on idle...meaning does it go up and down by it self when the car is not in motion?
4. Who should I have install this? A friend who is a mechanic or the dealer?
Thanks!
1. Does it bogg down the engine at all?
2. Is it easier now to stall with the UR pulleys on?
3. Does the rpm fluctuate on idle...meaning does it go up and down by it self when the car is not in motion?
4. Who should I have install this? A friend who is a mechanic or the dealer?
Thanks!
#120
Seems like any problems don't happen immediately (unless installed wrong), but instead are more of a long term concern. I haven't seen one person with a G35/350Z (NOT an x year old Maxima) that has had problems using pulleys. Not sure about you guys, but I'm not keeping this car more than 60K miles (already have 21K with stock pulleys). There are lot more things to worry about around 100K miles than an under drive pulley. If someone has provable evidence (service records, lawsuit, proof of prematurely worn bearings etc etc) speculating is a waste of time. Same type of arguments can be made for aftermarket plenum's, cold air intakes, rear diffs, any any other mod not "approved" by the vehicle manufacture.
If there was a problem I'm sure we would have heard about it from Unorth. When Injen had problems with their initial design they let everyone know. People are bolting on forced induction components, blowing Nitrous etc and were worried about how three pulleys MIGHT cause problems in 50-100K miles. Come-on... I wouldn't buy some crap made in a guys garage like on EBay, that's why I went with Unorth. Cant wait to have my local Nissan dealer install them this spring.
If there was a problem I'm sure we would have heard about it from Unorth. When Injen had problems with their initial design they let everyone know. People are bolting on forced induction components, blowing Nitrous etc and were worried about how three pulleys MIGHT cause problems in 50-100K miles. Come-on... I wouldn't buy some crap made in a guys garage like on EBay, that's why I went with Unorth. Cant wait to have my local Nissan dealer install them this spring.