http://www.2kracing.com/350z-engine/


Underdrive Crank,Alternator,
Water Pump,Power Steering Pulley
Fits on 350Z

Anyone else thinking about going this route or already have??

If so let me know what you think, what would the good and the bad be for going this route.

I use to have it one my old 91 300zx and i really could feel a difference.


Later
Aceman

 

I was interested in pullys but my mod mechanic suggested against it. What are the pros and cons of pullys?

 

i too am interested in them but i would like more information on the pulleys as vova and aceman have both stated....someone please enlighten us

 

honestly, if you guys wanted to save some money....just take off the three pullies that are on there and have them drilled (lightened) and balanced. not sure how much that would cost...but i'm sure it wouldn't be as much as buying all new ones. true??

 

aftermarket pulleys are both bigger and lighter.

With this tey have to rotate less freeing some of the power that they normally rob from the engine. being lighter they have less rotational inertia again helping to free some power.

i dont think that they affect the normal performance of the engine, and they're safe to run.

You can expect gains between 8-10 hp

 

has anyone bought them/ dyno them yet? How do you think they would work with the jun lightweight flywheel?

 

I'm a little concern about those pulleys. I've seen too many engines break because of the vibration created by the poor balancing of the pulleys. I have a friend with a Matrix who has broken 2 engines because of the vibrations in the engine and he has the unorthodox pulley. He is the service manager for a local Toyota dealer so he doesn't give a damn, but I do.
10hp is a lot, but I think is too risky for my taste.

 

I really love modding -- its a hobby for most of us. Buy a bolt on part and inch your way towards a little more performance. $300 here, $1200 there.

But here's what I don't understand:

If a bigger, lighter, set of pulleys are going to provide 10hp more... why wouldn't nissan incorporate this straight from the factory in the first place? It would cost them pennies.

Same goes with the intake/exhaust system.

The aftermarket performance part industry is getting bigger and bigger, especially with movies like F&F. Are we fools buying snake oil or is it just a hobby that makes us feel better and gives us something to do with our new toy.

I also see it in the computer industry... you could buy the super-gaming machine from the future with 10GHZ CPU, GEFORCE 100FX video card, etc... and run your game at 1000 frames per second, but truely, anything over 30 fps is useless.

I guess we're just good ol' American consumers feeding into the advertising and marketing ploys of these incredibly creative producers.

Just an observation.


PS. Any idea on a release date for this pulley set??

 

Hiya all,

Ok heres what I know about the pulley. If I'm wrong please step in I'm just sharing what I have learned and if I'm mentioning anything wrong please correct me

Stock 350Z crankshaft pulley weighs 5.7 pounds

I believe the Unorthodox will be a little over 1 pound

Now the idea behind having a lighter pulley is to put a less of a load on the engine. Just imagine the crankshaft spinning, the less weight it has to spin the quicker it spins. Thats why when you get a light flywheel for example your revs go up much faster.

Pros: you usually gain horsepower because your taking weight off the existing pulley.

Con: The Unorthdox and most pullies don't have a harmonic dampner. Now I haven't really looked into the 350Z one yet but it is fairly light already. Considering the fact that 300ZX one was around 15 pounds stock. This has always been a big debate that it could cause premature weight on the bearings. But the idea is that you shorten your engine life.

I have heard a lot of other things but this is what is usually debated. So there really is no answer if this will be a worthwhile mod but I'm sure it will be debated. I'm sure we'll see Dyno results as well but I don't think this item is out yet for the 350Z but I could be wrong

Hope that cleared some things up..

zya
Yuichi

 

In addition to my Z, i also own a '91 MR2......i put the unorthodox crank pulley on it about 70K miles ago....the mechanic told me that i would experience vibrations from it.....i felt vibrations, but only at 100mph and up....the vibrations have rattled my alternator loose a few times (BFD), but i have never had anything serious come from it.......i plan to get the full set of pulleys

 

What does each pound of weight savings translate into HP freed up??

later
Aceman

 

http://www.nissanperformancemag.com/...r02/altima_ur/

Here is what they said about the new Altima, not sure how much more will come out of the 350z as far a HP

Adding the crank pulley can be a little deceiving compared to other mods because there isn't a definite surge anywhere in the powerband, so the seat of the pants dyno is no good here. To verify the increases we headed up to R & D dyno to measure the results. There's a progressive gain in power of 2-3 hp from 2-4K RPM, after this the increase in hp is approximately 4-5 until 5K RPM where we gained 6.5 hp over stock and 3 lb ft of torque.


Later
Aceman

 

Power gains are obtained in two ways. First, and most important, is the weight loss. An average of 2.7 HP is gained from every pound lost off the crank shaft. 85% of our gains are from weight loss.


http://www.seffects.com/catalog/prod...e=UNO021011002

later
Aceman

 

Not to steal the thread, but you must not play many games, or have much expectations of them. If you are a die hard FPS player like I am, then you need at least 60 fps to play well in all situations. A more intense situation will strain everything and you don't want to drop too many frames, or you'll get fragged before you can see it.

 

You can still get the accesories pullyes (i.e. alternator, etc) and don't get the crank pulley. You will have the best of both worlds.

 

what about any electrical side effects?

 

I had the pullies on my 1991 300zx and really the only thing i noticed was that the AC did not blow as cold when you were sitting at a light, but once you were moving it was fine. The other thing i heard was if you have big stereo system your lights will dim more with each hit from the bass.

Later
Aceman

 

If you have a powerful sound system and are experiencing dimming lights, you may run a stiffening capacitor to provide the necesary juice for the system.

i dont think that the pulley has any adverse effect on the electrical or any other system

 

supposedly, if the pulley has the same dimensions as the original one, you shouldn't feel a difference because it still completes the same amount of rotations (with less energy loss spinning the pulley). So, if they are the same size but lighter, there should not be any difference.

Correct me if I'm wrong, this is what I have read.

 

Being lighter is an indirect benefit, but the real benefit is they are under driven, meaning smaller ratio. So its not so much they make power, but they give you back some power that is already spent turning these accesories, the obvious cost for this power is less rotation of the accesories that were under driven.

Ive been waiting for this topic to come up. No topic makes people draw party lines, baracade the doors, and post more of these guys on the twinturbo.net forum than the great under drive pulley debate(acctually twinturbo.net doesnt have smileys, but if they did...). I dare not post my feelings on it here lest I begin the blood shed on this board, just go there and do a search for it