Hey Skorch, where you having all your work done ? DIY ? planning to track it ? would love to see another 370 at the next NASA event !! :)

So far I've installed the CAI myself and the HFCs with the help of my buddy. He used to be a mechanic at Lexus and has a very nice selection of tools, so I have him help me with the more difficult installs.

As far as tracking, I've never done it before so I wouldn't even know where to start. I've only taken my previous cars to the drag strip but never to an actual race track. I figure it would be fun to do though.

You're in for a treat ! First timers get lots of coaching and support - it's real easy to get in to... all you have to do is sign up for the next NASA event at PIR (phoenix international raceway, where nascar was a couple weeks ago) and show up... You would be in HPDE1 which is a student run group... there is almost no passing allowed... instructor at all times... very safe... you just need a helmet, but can borrow one if needed

here's an email about the next even from our regional nasa director in az

there are other clubs too of course - like pca, bmwcca, etc, but this one is the best to start with if you're in a nissan

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Greetings!

If you've been waiting for the long distance weather report, things are looking great! We are in for a treat with some mild May weather. No rain, no wind, but luckily a few clouds to help keep the direct sunlight from frying us all! The forecast shows lows in the 60's and the high only being 90 degrees for the weekend. As a reminder this is your last chance to run PIR until SEPTEMBER!!! Also, because we were able to get an early May date this year, this will be the coolest May event we have had in quite some time. Get your track fix in NOW before the Summer heat hits us!

Register here (before prices go up next week) --> https://secure.drivenasa.com/event/906

DRAFT Schedule and event details here --> May 2nd & 3rd Event Registration now open - PIR - NASA AZ

Anyone have dyno numbers before and after for the Stillen crank pulley, yet?

I'm still skeptical and don't want to buy any unproven parts because my funds are limited and I'm saving my money for an electric supercharger. ;-)

It makes sense why the underdrive pulley increases dyno numbers, but not the lightened stock diameter pulley. My logic is that if SRM can blip the throttle from 3,000 rpm to 6,000 rpm in under a second, then a 6" pulley with a moderately lower moment of inertia shouldn't significantly alter the ability of the engine to rev from 3,000 rpm to redline over the course of a 25 second, fifth gear dyno pull.

No offense intended, but this sounds like you guys made up this logic to sell your product.

The post starts by saying it IS a harmonic damper. But... Goes on to say that the rubber is put in this 6" cast pulley to protect the engine from vibration caused by the pulley. If that were REALLY the case, every pulley on the engine would need a similar damper. Small vibrations going in to finely balanced power steering pump would be way more damaging than small vibrations going into a 300 pound engine that has explosions going on inside that apply thousands of pounds of asymmetric load on the crankshaft. The bottom line is that the stock pulley is a harmonic damper and the Stillen unit is not. The vq37 is known for it's poor vibration/harshness qualities at high rpm and the stock damper is there to damp the vibration and harmonic frequencies. It may be true that the engine will survive to it's normal life expectancy without damping those harmonic frequencies, but the engine will be subjectively harsher.

No offense taken. The stock crank pulley is NOT a harmonic balancer for the engine. It does have the ring in it to help with NVH from itself to not go back into the engine (and is the only pulley directly connected to the engine), which is internally balanced. The STILLEN pulley is balanced and extremely precision cut.

There are hundreds of pulleys on VQ37's with no problems, and thousands more on VQ35's.

It's been suggested (and referenced to other makes and models with horror stories) that these are "dangerous" to the motor, but in their application, and due to the precise process that these are developed, these problems just don't exist.

Let me chime in and tell you I've had the pulley on for over a month. It's fantastic. I feel a difference in my throttle response and I can't feel any loss in power from my air conditioner. I drive my car daily and drive it on the track weekly. It's an inexpensive mod that you will be able to enjoy the results.

Also, the engine is a lot less harsh at the higher RPMS since I added my stillen exhaust and intake.

You and I have the UD pulley though. Phimosis' skepticism is directed at the lightweight pulley from Stillen that's stock diameter, not the one we have.

Something is fishy here. The picture of the crank pulley that Wstar and the picture of the crank pulley that Josh at Stillen posted both have holes drilled on the back side of the inertia ring of the damper, but the holes are at different positions. This indicates the pulley IS balanced. It is a common technique to spin the object, then drill holes to remove metal, drilling the holes deeper to remove more metal as needed, to balance the rotating object.

For a better explanation of whether this is, or is not a damper, read the article by Steve Dinan, of Dinan racing:

http://www.dinancars.com/bmw/technia...armonic-damper


Also, the response from Stillen didn't adress my primary arguement, that if the pulley needs to be damped to prevent the pulley from damaging the engine, then every other pulley needs to be damped to prevent damage to the water pump, alternator, AC pump and power steering pump, but they are also cast units that do not have rubber dampers. I swear you guys rationalized your logic after you built the part. Show me some evidence that your argument is correct. Maybe some whitepapers from Nissan?

You're absolutely correct.. I should have been more clear.

The stock pulley is balanced via the removal of material, but is not a harmonic balancer.. please forgive my mistake. But no where near as precise as a billet cut CNC'd piece, hence the NVH ring in the center. You couldn't have it be just the pure cast piece with slag hanging off different areas.

so to simplify all this stuff for newbs like me. if i get the lightweight one, WILL IT HURT ANYTHING?

PS.... The reason I am taking such a critical eye on this issue is that I really want to put a lightweight pulley on my Z..... I'll do just about anything to make it faster and it already has a plethora of Stillen parts on it. I just want to make sure I understand the risk/benefit ratio on each piece before I take the plunge.

Curious on why lightweight vs. U/D for you Phimosis?

(and thank you for your orders.. you're practically a rolling STILLEN billboard!) :D

Maybe he's planning to SC in the future?

I kinda am too, long term, but given the cost and complexity of the SC install, it's not like it would be a big deal to swap the pulley at the same time.