I don't always feel good overlaying the thinking of the design engineers with my own design theory. I'm not sure how long I will keep this thing so I may be too conservative for this. I WANT MY ECU

 

The crank pulley on the VQ is NOT a harmonic damper. The pulley off the VE series motors (pre-94, 300ZX, some Maximas) had harmonic dampers. My Maxima FSM never refers to the pulley as a damper nor harmonic damper. It's always just the "crank pulley". We went through all this harmonic balancer stuff over at Maxima.org. I've been running a UR pulley for 2 years now with lots of runs well over 6000rpms. Also plenty of 2002+ Maxima owners are running the UR pulleys. There has never been one recorded crank failure with a VQ at Maxima.org. Guys have hydrolocked their motors and bent their connecting rod 90 degrees, but the crank was completely fine. Even guys with turbo VQs pushing 320fwhp+ have pulleys. Believe me, I did a ton of research before installing the pulley on my VQ. Some cars like BMWs, LT1 Camaros, COntour SVTs, etc don't react well to pulleys because thier crank pulleys are harmonic dampers. The VQs i not.

The VQ is an incredibly stout motor and the forged crank is already balanced. Putting a 2.5lb lighter pulley won't harm things. There has never been one recorded crank failure with a VQ at Maxima.org. Guys have hydrolocked their motors and bent their connecting rod 90 degrees, but the crank was completely fine.

What you will notice if you have a manual, it that the rpms fall faster between shifts and starting out smooth is harder because you have less inertial weight on the motor. The gains are there both on the track and on the dyno.


Dave

96 Maxima SE
14.45@99.51mph with a 2.316 60'

JDM intake manifold, JWT ECU, Y-pipe, UDP, hacked stock airbox, 2K Maxima muffler

 

Another response from UR Racing:

Yes, we saw this when it was originally posted. While the posting extracts
information from what is truly an excellent book, it leaves out some other
points made in the book about the actual significance of "torsional twist"
in real-world applications.

In the BMW application, we are dealing with a long crank shaft. This does
have more "twist" than a V6 like your VG motor. But, this "twist" is well
within the safety range on the street and certain race cars, in that the
twist does not cause enough stress on the crank to cause any pre-mature
failures. In an application where you are running road coarse and are at a
constant higher RPM and where you are stressing the motor to it's limits, a
damper is important and should be taken into consideration. Again, it really
depends on what stresses the motor is going to be seeing and this is when
you really need to talk to the engine builder.

Now in the case of your motor, you have absolutely nothing to worry about.
Nissan has done an incredible job building this motor. You will see no
issues running the aluminum pulleys. We've got 7 years under our belt with
no failures in any car or application... EVER! So that is good testament to
"real world" use.

Jim


Luv My G

 

"This does have more "twist" than a V6 like your VG motor."

The UR response is talking about the VG motor which was used in the pre-94 Maximas (except SE 92-94s). The VG uses a harmonic damper and isn't near as strong as the VQ so this is even more proof that the UDPs are not an issue with Nissan V6s. Personally, I wouldn't risk running a UDP on the VG/VE motors because they do have dampers, but the VQ is safe.


Dave

96 Maxima SE
14.45@99.51mph with a 2.316 60'

JDM intake manifold, JWT ECU, Y-pipe, UDP, hacked stock airbox, 2K Maxima muffler

 

ok, don't put on your car, sell em to me!

pm me

Better Life thru Chemistry

 

I'm looking to buy pulleys. Anyone know where i can get them?

Thanks - Joey Avino

 

www.i-m-racing.com has the G35 UR kit...I don't know if I'm going to install them now, though...I haven't heard good things...I might just see for myself though...

"All the Power in the World resides in the Eyes..."

 

F-it, I just put mine on today, along with my Borla exhaust and greenstuff brake pads I am good for now with my mods, until someone comes out with a better looking plenum that gives the advantages of the crawford.

Luv My G