Was wondering if anyone had any insight on this..or has one on....i was wondering on getting this or getting a torque convertor upgrade...which one would help the most compared to the cost..

 

This is another useless mod that will yeild you 1 hp.. i am glad i caught you this time before you bought it and before you spent money on it like the Jet Chip.. do a search in the genral forum.. i broke this mod down.. i will try to find it for you

 

here you go..

read the comments.. if you still feel the same way and want to buy the Pulley.. go right ahead.. but read this post 3 times first

http://forums.maxima.org/showthread....ghlight=Pulley

 

thanks for the advice..the reason i had asked is that today i went to the scca thing in lexington at the baseball stadium..i talked to a guy with a sentra and he had headers, exhaust, intake, and pulley..and he said he really liked the pulley and it made the biggest difference..i guess it's diff. for a sentra than max......what do you think about a torque convertor upgrade???? i need something that is good for the $ and adds power while staying NA....advice please.....thanks

 

How about a y-pipe?

 

Had this thought too...but don't know what to do with my $..since i spent so much on the Jet chip and didn't get much gain..i want to be careful....and want to know the best for the $...i heard good and bad things about the torque convertor and didn't know how much gain the y-pipe actually gives....any more advice would help..

 

for 5th gen it gives like 10hp to the wheels i think, very noticeable gains.. y pipe and CAI are the bang for the buck

 

Until someone dynos the pulley, we really don't know what kind of power it makes. We cannot sit here and say that it only makes 1hp without any dyno verification. I use to be very against a pulley on the Maxima until I did a lot of research and found out the stock pulley isn't a balancer. I do know for a fact that 4.6/5.0 Mustangs gains over 12 rwhp and 18ft/lbs of torque with just a pulley swap. I also know that SR20DE gain ~5 fwhp and 8 fwtq from a pulley. It may work for the Maxima. The stock pulley weighs about 6 lbs while the UDP weighs in at 1 lb. Much of the gain that comes from pulleys is due to the fact that they reduce inertial weight. The 20% underdrive does very little in the way of performance.

SprintMax:
The fact that you beat cars with more mods is kinda meaningless. All cars run a little differently and all drivers have different skill. These two variables are more than enough to make the same model cars with +/- 10hp perform nearly same.


Dave

 

I respectfully disagree. We know exactly how much power it makes. Zero.

A modification to the engine may increase power. A modification to the exhaust may increase power. An UnderDrive Pulley makes no power.

The performance benefit of a UDP is small but real. It reduces the accessory loads by turning those rotating components slower than the stock pulley. It has less rotational inertia than the stock pulley.

 

I knew someone would bring this up Yes ,the UDP doesn't ADD power, but it does unleash more power from the motor that was otherwise lost to rotational inertia. The "gains" of pullies have been verified on dynojets. The same goes for heavier wheels. SCC just did a article on how much power is lost to heavier wheels (ie added rotational mass). The same thing applies to the lightweight pullies.

Supposedly, for every 1lb you shed in rotational mass, it's like gaining ~1.5 hp flywheel hp. So adding a 5lb lighter pulley could technically add about 6 fwhp. A gain? Yes.

After reviewing dyno plots for pullies on Neons, Hondas, and Mustangs, I can see why people say they feel more lowend, but little gain up top. If you look at the plots, the gains are elevated at all rpms. The powerband isn't extended like to more topend (like a y-pipe, intake), instead it's deepened. This is why they don't "feel" much on top.


Dave

 

Let's be careful with this generalization. According to http://library.thinkquest.org/16600...alinertia.shtml the formula for the moment of inertia of a disk spinning about its central axis is I = 0.5xMxR*2. The radius R is important in this formula. It tells us that eliminating a pound from a road wheel or a flywheel is much more valuable than removing a pound from the crankshaft pulley because of different dimensions. The road wheel has a radius of 7.5-8.5 inches while the radius of the crankshaft pulley is approximately 2.5 inches.

 

so even if the pulley added power though,wouldn't it reduce the PSI of a super charger? That wouln't be good

 

Check that link i posted.. Tony C .. did dyno the pulley it was 1 hp gain

 

That's why it's not recommended on SC installs.

Daniel thanks for the radius point. Nice explaination.

But the smaller pullies also consume less power to turn the accessories. I think that must be accounted for in the pulley gains. But I honestly don't know how much % is represented in it though. ie... 50% from a smaller pulley 50% from less parasidic loss from the accessories etc..

 

I don't see any dynojet plot in the link you posted. Tony might have only gained 1hp up top, but what about thru the rpms range? Did e run on the same dyno? Did he run different wheels? Was his engine hot?

Dave

 

As far a accesories go, I know the pulley is supossed to reduce the wear and tear and those by reducing there rotational speed. If you run your Rpm's up to the 6k range a lot, you wear out the driven components faster. The pulley might be worth the saved cost of a new Alternator. just my $.02