they really stress your alternator and can blow your electrical system, many failures due to these pullies, dont get them

 

oh lord.... the sky is falling, the sky is falling!!!

hrmm... can't argue with results here...

guess my 1000+ watt stereo will just have to get thrown out... pbbbbttt or not...

 

I can't beleive I am responding to this but ..... No the pulley(s) don't stress your Alternator. In reality , if anything they reduce the average RPM you alternator spins and may extend it's bearing life.

Now the only downside would be if you run many-many power accesories at idle as a rule, it could shortenyour battery life due to repeated deeper cycling. With standrad OEM-like Electronics there should be no notable issues, However; If you are running major power AMPs or like to play with your power windows repeatedly in heavy stop-n-go traffic, then the crank pulley may not be for you.

99% of the gain comes from the reduced crank pulley diameter (accessory underdrive) and reduced mass. The Alternator and water pump pulleys are primarily just cosmetic , regardless of the UR claims.

 

That's not necessarily true. The company I used to work for designed the alternator/water pump/power steering pulleys to provide 8-13whp gains without changing the crank by making them lighter and larger. However, changing the crank pulley is an easier/lower-cost method.

Does anyone know whether the stock pully has an attached dampener? If it does not, then there can not be an issue. If it does, then I can have pulleys made with a fully dampened (active-dampening, which is better than stock dampeners) crank pulley.

 

absolutely 100% untrue...VQ guys have used these for years.....hundreds of thousands of miles among them (probably millions at this point), without incident.

stock pulley does not have a dampener in it - it does have a small insulator rubber to keep noise levels down

 

I installed all three pulleys, just becuase I was bored and could. However; as an engineer I can tell you that rotational mass of the stock water pump and especially the alternator pulleys are insignificant to overall power on the VQ35. Also note these UR pulleys are the same diameter as OEM. The UR crank pulley is were the significant advantage lies. If you got the expendable cash , install all three, if not, the crank pulley is were the value is.

The OEM crank pulley has a rubber isolation ring intended to reduce belt noise transfer , not to balance the rotating assembly. The UR crank pulley is far lighter than the OEM and is smaller in diameter , hence the accessory underdrive effect.

 

engineers always know how to say it better

and to clear up what G3 said, the crank pulley is mildyl underdriven and much lighter....the other 2 pullies are lighter but same dimater.

once again guys, no one every seems to question going from a stock 28 lb flywheel to one of the lightweight ones...this is the same thing, but on the other end of the crank!

Adam

 

yup, and with the tilton and the U/R pulley set i'll be losing about 65% of the additional mass on my crank

 

I ran an UR crank pulley on my '94ZX for over 90k. Never had a problem. I did notice my windows going up slightly slower, fan didn't blow as hard - all due to the underdriving. Again never a problem.

I'll be picking up the crank pulley for my '03 eventually.

 

Please excuse my dumb question (still learning).

Is it possible to get a lightweight pulley without changing the diameter (without underdriving)?

I would be interested in the lighter rotational mass, but not the underdriving.

If it is possible, who sells them (with stock diameter)?
What is the stock diameter?

Thanks

 

well, i just know that on 2 of my buddies mustangs, engine deaths were directly attributed to the crank pulley

I have no experience really with the VQ in that respect

sorry for talking outta my ****

 

While your story is insanely vague, I've read about catastrophic engine failures that were attributed to ud pulleys. Everytime, there were aggravating factors(from bad installs, to plain bad use).

I know people who have been running pulleys on all sorts of stangs, some for more than a decade, and never had any problems whatsoever.

That's why the "bad for the engine" story is hard for me to believe. Why do some people have problems, and other not? Imho, the only logical explanation, is bad install or inapropriate use...

 

Typical post.... "buddies" being key.


Well, let me tell you this: I've owned TWO Mustangs and had underdrive pulleys on BOTH and had no problems.

Stang #1: 1985 Mustang GT 5.0L (Where abouts unknown, was fine when I left it...20k+ on pulley, and it was 8 years old at the time of install)

Stang #2: 1996 Mustang GT 4.6L (Bought new, pulley on in first 2k miles. Spotted recently, still kickin, which means it probably has 100k+ miles on it by now, I sold it in '98 with 35k miles)

What bugs me is that it's always "My mechanic said" or "my friend said" or "I knew this guy who's sisters cousin had a best friend" story that gives these pullies a bad name.

1998 Integra GSR: 30k miles, UR pulleys, no prob
2002 Maxima SE : 30k miles, UR pulley, no prob
2003 350Z: 19k miles, UR pulleys, no prob

Last time: I've owned 5 different cars with UD pulleys with 4 different engines and had NO PROBLEMS!!!
(My 02 max and 03 Z "share" the same enigne kinda)

 

I got the set...love 'em! Crank pulley for the gains, and the other two for bling.

 

but see, i think u all have 6mt's i wanna know if its gonna screw the 5at

 

makes no difference what transmission you have

 

thanks, ill be ordering mine in about 20 minutes

 

I have had mine on for 150,000 miles and i rev my car to 8000RPM . And had no probs

 

has ne1 used these with a turbo kit? would they work with a turbo? would it cause more wear?

 

Yes and no it won't cuase more wear. The only main side effect on a Turbo car is if you auto-x or drift your car in hot climates , spinning the water pump more slowly may exacerbate cooling issues. This can be offset by a higher capacity radiator and/or an extra oil cooler. For street use, you shouldn't see an issue.