I don't have any real opinion on the real topic of this thread, I just wanted to chime in that the orc 409 does have a "silent" or non-vibration option or whatever you want to call it for its integrated clutch/flywheel, achieved through actual springs set in the flywheel. See first pic:
http://www.oguraclutch.co.jp/orc/orc_ex~1plate.html

 

The mass and size of the clutch/flywheel/torque converter acts as a damper. The damper used in the dual mass unit on the 6MT is to quell mechanical noise. We all know how noisy the VQ35 drivetrain is with a non-dual mass setup. A torque converter is an even better damper thanks to the fluid within the converter hence the reason why the autos transmit a bit less drivetrain vibration. Like I said before, the shear weight of the clutch/flywheel/TC is what acts as the damper.

The crank could care less which damper is mounted to either end, but there needs to be a damper on both sides not just one. I don't how much more clear I can about this.

 

OK - so now the 7 lb crank pulley HAS to have a small, 1/4 inch thick rubber ring glued into it, but the flywheel can be of any mass (even down to the 9 lb clutch and flywheel ASSEMBLIES (9 lbs combined weight for clutch and flywheel), which are widely used in motorsports on the VQ's, without the "extra" dual mass setup, and yet the motor still stays happy inside.? You've got to be kidding me....

Again, have you had the clutch/flywheel on a high speed balancer to see how "balanced" it is? I have. And again, explain how dropping from a ~5 lbs clutch flywheel combo to a 25 lbs clutch flywheel combo is somehow "better" for the bearing life and torsional movement of the crank, than dropping from a ~ 7 lb crank pulley to a 2 lbs one? If assuming your theory of the crank pulley having a role in the internal harmonics of the crank are concerned, then certainly it can easily be said that it obviously plays far less of a role than the clutch/flywheel, but the mere fact that it weighs so much less to begin with. That being the case, again, why does installing an aftermarket flywheel not affect things, but you theorize the crank pulley somehow does?

Interestingly enough, Subaru uses the EXACT same setup on their crank pulley as Nissan does - a small, 1/4 inch piece of rubber that is GLUED into 1 side of the pulley. When they were asked what the purpose of that rubber ring was, here was their reply:

"Thank you for your patience as I checked with our Technical Services Department regarding your message below. They advised that the crank pulley is a pulley and nothing else. It is not used as a harmonic damper/balancer.

Thanks for the opportunity to be of assistance. If you need any future assistance, please feel free to contact us again."

Best wishes,

John J. Mergen
Customer Service Department
Subaru of America, Inc."

Now again, I can't comment on the pulley design of every car manufacturer out there, but I know Subaru's and I know Nissans and I know both have crank pullies manufactured in an identical fashion.

 

Yes, I am quite familiar with the design, but again, the purpose of the springs is to keep noise to a minimum in the clutch. Traditionally, integrated clutch-flywheel units like Exedy, OS Giken, Ogura, Tilton, etc are very noisy when the clutch is disengaged, and rattle a bit when you engage them from a dead stop. The purpose of the springs is to help dampen the noise, not somehow aid in the torsional movements of the crank.

 

Subaru is a great company and all, (not being a $mart @ss) but any chance of getting a statement from Nissan, since that's what we drive?

 

I've already asked....chasing down the right dept to answer it is a bit of a needle in a haystack but any reply we get, I'll post here

 

First off, the elastomer ring you're talking about is simply not just "glued in there". The crank pulley is actually two pullies glued together with the elastomer ring acting as the media that attaches the two pullies. FYI, that ring is specifically known as the interia damper ring. The VQ30 uses a similiar design and I've seen pictures of a heavily weather 300K VQ30 crank pulley that actually had the ring fail and the two pullies completely seperated. This two pulley design is used in most every late model engine currently produced.

Secondly, it doesn't matter how balanced the aftermarket pulley is. The facts are it doesn't have any damper material. That's the issue.

Take specific note of the LS1 crank pulley (known as a crank damper) which uses the exact same design as the VQ crank pulley. Note the ring in the LS1 pulley and also note how the aftermarket LS1 pulley vendors use interial rings on their pullies. Kind of makes you wonder why VQ aftermarket vendors don't under the concept here. My guess is the market is too small and the R/D is too high to justify the engineering. Instead of making the better product, they'll prey on people's ignorance.

http://www.chevyhiperformance.com/te...s1_engine_mod/

http://www.gmhightechperformance.com.../photo_39.html


Interesting because my Subaru FSM for my wife's 1998 Legacy GT and the Chilton's manual both refer to the crank pulley as a "crank pulley/damper". I think I'll trust the Subaru engineers over what the operator of tech line says.

 

Underdrive for cars with no plan to supercharge or install a stereo over 600 watts RMS.


Shawn Baumgartner
President
Unorthodox Racing

 

If I had a dollar for everytime I herd this I would actually be a millionaire. The factory crank pulley functions only as an NVH (Noise, vibration & Harshness) damper for the occupant compartment. The factories make the interior of the car super quiet just like the baffles and resonators in the intake and exhaust, which are by the way the first thing everyone rips out to put a cold air intake and cat-back exhaust. We are celebrating our 10th Anniversary this month, if we were wrong about this we would have been out of business in the first 3 months of operations.


Respectfully,
Shawn Baumgartner
President
Unorthodox Racing

 

Working on the 2007 pulley now, should be ready by sometime in late July.

Respectfully,
Shawn Baumgartner
President
Unorthodox Racing

 

Thank you... That's why I'm sticking with the dampened factory pulley to prolong bearing life. There's other ways to improve throttle response without promoting undue bearing wear -- Like a short ram hi-flow intake, grounding kit, etc... But to each his own. Maybe you guys could start marketing other performace items as well?

 

Balance and quality of components used internally, the amount of TDC dwell time, oil volume & pressure determine the durability of a given engine. Fluid dampers are not well suited to racing as they were originally designed as Diesel dampers for use at low RPM (under 3000 RPM), the weight in the fluid locks up at higher RPMs rendering the damper completely ineffective. The valvetrain in late model OHC engines is not effected and does not effect engine efficiency from a damping perspective.

Respectfully,
Shawn Baumgartner
President
Unorthodox Racing

 

10 years on the market this month, 2 years of develoment prior to coming to market. How many more years of facts do you want? I have a 93 Supra with an I6 and have had the pulley on for over 30K hard miles with no problems. We were domestic V8 guys and we thought they were dampers too. It is just not the case and if anyone qualifies as an expert on this subject its us. I know first hand from an OE standpoint that the dampers are designed to quiet accessory noise. My brother in law used to be an engineer for Honda at their Anna Ohio engine plant and I saw first hand all the different frequency crank pulley designs they tested (hundreds) to find the one with the quietest audible acoustics. Many were even solid pulleys or various designs with no elastomer. None had any effect whatsoever on durability, the egines never lost more than 2% power after 1000 hours at max rpm and 2000 hours at peak HP. It is also not just a function of a specific Decibel reduction and has much more to do with overall vehicle resonances so the total vehicle package is quieter.

Respectfully,
Shawn Baumgartner
President
Unorthodox Racing

 

A spun bearing has nothing to do with pulleys, more to do with improper oil viscosity, oil overheating and thinning, over revving, revving when cold, poor oil pressure or volume or poor bearing clearancing on re-build.

Respectfully,
Shawn Baumgartner
President
Unorthodox Racing

 

For the record, I've had my UR pulley for a long time. I track the car every now and then and I've never had any trouble with it. There isn't really a noticeable amount of increased power, but the throttle response is a very welcome outcome.

 

Who the heck are you? You show up to this forum with 6 posts all posted in this thread claiming to be from Unorthodox... Yeah right... Maybe a Mod could do an IP check...

By the way -- If anyone is the expert it's Nissan, since they have been in business for 50 years, built the car we drive, and have spent millions along the way on R&D.

 

Says who he is right there....

Shawn Baumgartner
President
Unorthodox Racing

IP check...lolol - yeah because it's all just a big conspiracy....jeeez

 

It is your lack of respect for other credible people and your unfounded & unsubstantiated rhetoric that is GROSSLY pathetic.

Shawn Baumgartner
President
Unorthodox Racing

 

Nice! Someone who actually insults other people using their brain and extensive vocabulary rather than their base knowledge of the english language and unerring ignorance! UR guy FTW!

 

That's because they don't cost $150, only cheap low quality knock-offs of our pulleys sell for that amount of less. They are unbalanced and do not fit properly which will throw off balance.

Dollar for dollar no mod, other than programming or possibly a downpipe for turbo cars even comes close to the HP per dollar gains of our pulleys.

Respectfully,
Shawn Baumgartner
President
Unorthodox Racing