pulleys and tuners

[2wdmuddin]

im about ready to add to my motor, i was looking at the uderdog pulleys and my question is, do i need the 4piece combo or can i get just the crank pully and get the 8 hp and 11fp of torque? also where can i find a tuner for my truck

 

[disciplerocks]

UDPs are pointless. Trust me. And if your truck has OBD-II then I suggest going with SCT tuner, if not then you are stuck with a chip. Good luck either way.

 

[Froggmann]

Just get the crank pulley. Underdrive pulleys are the best bang for the buck out there, more power and better fuel economy.

 

[disciplerocks]

Um no they are one of the worst things to spend your money on next to aftermarket throttle bodies.

 

[rangerrookie429]

If you buy the whole set you get new pulleys for your accessories to compensate for the underdrive pulley. Otherwise your accessories will be underdriven, I'm not really sure how big of a deal that is. As for the tuner, this guy writes tunes specifically for the Vulcan http://rogueperformance.com/RogueCustomTuning.html. He's a big dog over at ranger power sports, goes by Boss3.0.

 

[feellnfroggy]

most underdrive pulleys dont compensate for teh accessories because it negates the crank pulley in the first place. However a mild underdriving is ok and will not hurt anything(unless you run a big power alt and equip) It is a good bank for the buck, but does not create more horsepower, it works the same principal as installing 4.56 gears in a truck with 3.27's you'll 'feel' more applicable power. They dont necessarily free up horsepower, just free up drag. They are worthwhile when applied properly.

Aftermarket throttle bodies are a good mod too. Aftermarket throttlebody spacers are not. (however the aftermarket throttle body will do no good if the intake tube is smaller than the throttle body.)

 

[2wdmuddin]

disciplerocks, what makes the under dirves pointless?
my trucks a 94 so its obd1, the jet chip is the only performance module ive really heard about, are there anyothers? also how much will a chip help

 

[disciplerocks]

I just think its pointless to spend $50-100 on something that most of the time can't even be seen on a dyno.

 

[Froggmann]

Dyno proven 8 hp and 11 lb-ft at the rear tires on an auto equipped 3.0. They do work very well. I have one with an electric fan and have zero overheating or charging issues.

Underdrive pulleys have been proven to be one of the best bang for the buck mods out there, regardless of vehicle. They don't make power, just free up parasitic losses.

 

[Big Jim M]

hmmm

Dyno proven 8 hp and 11 lb-ft at the rear tires on an auto equipped 3.0. They do work very well. I have one with an electric fan and have zero overheating or charging issues.

Underdrive pulleys have been proven to be one of the best bang for the buck mods out there, regardless of vehicle. They don't make power, just free up parasitic losses.

I have never toyed with them things.. However I have THOUGHT about what they could do and when they could do it..
First off the accessories NEED a certain amount of HP.. No matter which diameter crank pulley is used them parts still gobble up that certain amount of HP!
So what I have surmised about underdrives is: At normal driving rpm the engine is still providing the same amount of HP loss to the accessories. EVEN if they too have underdrives on them.
So the possible GAIN would be at excessive RPM's. At high rpm the accessories don't use MORE HP than they do at lower normal rpm. There COULD be a gain from not supplying HP to the accessories that isn't being used by them. I cannot fathom the things being "felt" by the driver.
Now if the drive belts were taken off the crank pulley the engine wouldn't have to turn them accessories.. There is where the normal driving gain might be.
Big Jim

 

[disciplerocks]

Dyno proven 8 hp and 11 lb-ft at the rear tires on an auto equipped 3.0.

That would be the day. Must be at the crank which equals nothing at the wheels.

 

[Froggmann]

That was rwhp.

 

[ranger450]

frogman! i noticed on your sig you have done some throttle body mods, what have you done? would like to do same.

 

[stmitch]

I'm very happy with my pullies. You'll find that a vast majority of those of us who have "toyed" with them feel the same way.

I have never toyed with them things.. However I have THOUGHT about what they could do and when they could do it..
First off the accessories NEED a certain amount of HP.. No matter which diameter crank pulley is used them parts still gobble up that certain amount of HP!

This assumption is incorrect. It's not about what the accesories NEED, it's about how hard the engine has to work to give them what they NEED. The engine is able to turn the accesories more easily with a smaller crank pulley, which frees up existing power by reducing parasitic losses. The smaller pulley also slows the accessories down, which again decreases the amount of drag/parasitic loss, and is the reason some people with large electrical draws report dimming of lights, etc. And finally, the lighter weight of the aluminum underdrive pullies has a benfit, although small, over the heavy steel factory units (rotational inertia).

 

[feellnfroggy]

Guys the parts themselves create a certain amount of resistance due to the design oand clearances of the parts. such as friction inside the alternator or power steering pump. The pulleys are design to reduce the 'feel of the friction. Its plain as the nose on your face. when rolling down a hill and "pushstarting" a truck 37's will turn it over easier than 31's. Same principal, the larger (underdrive) pulleys allow the accessories to turn slower than they would with smaller pulleys. But the amount of work the engine does to rotate that accessory is lessened. Anybody race Xmods? Swap the gears and little electric motors?

They dont free up all the drag from the accessories, but they lessen the load by a percentage. 10% underdrive pulleys require 10% less effort to turn the alt or steerign pump or a/c compressor. However that accessory will turn 10% slower as well.

Someone push a cart with small casters and then push a cart with bigger pneumatic tires (larger diameter) tell me which is easier to push?