STILLEN is proud to release our Lightweight Underdrive Crank Pulley for the 2009+ Maxima 3.5L!



Pulley Features:


These underdrive pulleys benefit in two ways:

1. They are much lighter than stock, reducing the crank pulley weight from 4.32lb's to 1.00lb's.

2. They are smaller, underdriving the accessories by approximately 20%. This frees up horsepower from the engine, and puts it to the ground. This will spin the alternator slower, but only those with really large audio systems should be affected.

This is a relatively simple installation, our shop charges 1 hour of labor, but you will need a pulley puller, which can usually be rented from your local parts store, some places for free.

Being that this pulley is smaller, you will need a new shorter belt. STILLEN has these Gates belts in stock and can ship them along with it (Part #400344B).

We're offering these at an aggressive price. Shipping is on us to the 48 states, with $9.95 covering insurance and handling. Other shipping options and international available as well.

You can order online or give us a call at 866-250-5542

STILLEN Underdrive Pulley - 2009 Maxima 3.5L

Other Standard and Underdrive Pulley applications available:

- 02-06 Maxima 3.5L (coming soon)
- 95-01 Maxima 3.0L (coming soon)
- 350Z / 370Z
- G35 / G37
- FX35
- Altima / Sentra

 

Since you have a dyno on your facility, I trust there are dyno graphs for this mod on a stock Max??? Care to share??

 

Unfortunately with the CVT, it's impossible to get back to back numbers for a stock car, much less a before and after dyno for an installed product. The dyno graphs are reliably inconsistent.

As a side note, any mfg making claims on products with a CVT dyno should be considered suspect...

I understand what you're asking, unfortunately it makes it difficult for the 7th gen to get straight answers on product performance.

 

Gotcha. What are the 'theorized/calculated on paper' gains??

 

Josh - I don't doubt what you say about the CVT and dynos, but I'm curious why the Ds mode (manual emulation) can't be used to produce relatively consistent dyno numbers since the ratios are fixed.

I can think of a couple possible reasons including variable belt friction and maybe slight lack of precision in seating the belt in the exact same location every time. What are your thoughts?

Thanks,
John

 

How about just taking the motor out and putting it on a mount then dynoing the with mods that are hooked up on it, at least this should be able to give you the baseline??

Enthusiast don't really like to buy products that they can't actually see numbers to gauge what type of gain they're going to get, sure you/we can always use seat of the pants=buttdyno to ASSess the differences in before and after mods but nothing speaks for itself like a good ol trusty dynochart.

Just asking.

 

We tested and tested and tested the car on a dyno in every mode possible, trying to get a repeatable run, but to no avail. The problem is even in "manual" it's not.. the ratios aren't fixed.

And pulling the motor to test isn't going to happen. The complexity of getting the motor to run out of the car would be a feat in itself, ignoring the highly prohibitive cost for testing on a $150-190 item..

Underdrive pulleys have been around for a very long time, and are an effective upgrade, one that will benefit you now and with every additional modification you make to the performance of the car.

Here's a Turbo Magazine article from back in the day: Turbo Magazine - 350Z Underdrive Pulley Dyno Test

 

I've often wondered about the effectiveness of U/D pulleys. Theoretically, they work by robbing Peter to pay Paul. If lower rotational inertia (it's weight and diameter) made a difference, Nissan would have done it at the OEM level. There are literally many other parts that are involved in the rotating food chain before the hp grips the road. It would seem that a few lbs cannot make that much of a difference.

 

All kinds of rotational items do have an effect, you're absolutely right. Flywheels for manual cars, lighten that up and you see immediate results. Even wheels and tires. Add some heavy wheels and tires, you can easily see a 20-30hp loss in HP to the wheels.

In fact, with our supercharged Titan here, when we have it on display for a dyno run to show the power, we have to go back to the stock wheels from the 24's, or we'll see 40whp less on the dyno.

The crankshaft pulley is the largest pulley, and reducing the weight and diameter will have a measurable affect on the cars hp, and quickness to rev.

 

I buy the theory but dispute the need to shortchange power to the accessories to reduce rotational inertia. Ideally, this engineering would be done by the OEM. They could fabricate the pulley out of Titanium. Another way to use a carbon fiber composite sheave. Most likely, they have thought of these ideas and have discarded them due to cost.

 

Absolutely.. a titanium pulley would be lighter, and more effective, and astronomically more expensive. These are cut from a solid piece of billet aluminum, and machined down from CAD drawings for maximum structural integrity and minimum weight.



There are two schools of thoughts, and we make both standard sized and underdrive pullies depending on the application and the goal. The 2.5L Altima's cannot have an underdrive to the design, so we do a standard pulley to lighten it up. Underdrive adds additional power, but a lot is recovered from lighter weight alone.

 

Other Standard and Underdrive Pulley applications available:

- 02-06 Maxima 3.5L (coming soon)


Not CVT complications for us 5.5 gen dudes! Dyno shall accompany?

 

They are being machined as we speak, will be available by the end of next week at the latest. I'm a little short staffed on R&D and service folks, there's a ton of projects going on here, immediate dyno might be difficult, but I'll see what I can do.

 

why no 07-08 pully???

if the 09 CVT can have one, why not us too???

 

...you are not worthy...

 

Results are coming in from the 3.5L Altima crowd on the installation of this pulley.. if you'd like independent reviews:

http://forums.altimas.org/zerothread?id=399412&page=2

 

Another big issue is driveability. Joe Blow Businessman in his Maxima doesn't want to sahe 30lb of rotating mass. He wants to be able to launch his car off idle at a stoplight and have nice, smooth, chatterless clutch engagement. He also wants full steering response at idle for getting into those tight parking spaces.

Then there's "us". We want the most performance we can get, driveability be damned. We'll deal with having to slip the clutch at 3000rpm and a bit of vibration and a slightly stiffer steering wheel at idle in order to have more power available at 6000rpm.

FYI... with my underdrive pulley on my VE Maxima, my 10 year old stock alternator was putting out over 70A AT IDLE. rated output is 105A at 3000rpm. If you're using that much electricity at idle, you're going to be breaking several laws. Either WAY too bright headlights or WAY too loud of a stereo.

Underdriving the water pump (on SRs, VGs, and VEs that have a belt-driven pump anyway), also helps the engine cool at higher RPM. The SR's water pump spins so fast on the stock pulley set that the water just cavitates above 6000rpm and doesn't pump. Thus the engine overheats. slowing the water pump down causes the water to stay flowing, and it also spends enough time in the radiator to actually cool down. So the engine does much better heat-wise.

BUT... my point being, the OE pulley set is designed for one combination of price, comfort, reliability, and performance. Guys like us would rather have more performance and sacrifice some of the other three.

 

Thanks Josh for becoming a sponsor. I restored the threads that they locked down. If you see any I missed, PM me.

 

hmmmmm 2.7hp/pound (according to the unorthodox website) shaved from the crank should equal about 8.964 horsepower being freed up at the crank.

 

Nice! Just another part on the list.