Definitive is looking to make a OEM sized, lightweight Crank Pulley for us.

Price will be about 140...

My personal opinion is that this will give us faster boost spool, not neccessarily much added HP, but the ability to get into boost faster, which for me is exactly what I am looking for.

Any other takers post up in there. These guys seem to be on point, and their product looks like it is top notch quality.

Check out this thread

http://forums.maxima.org/showthread.php?threadid=210431

 

In order to get faster boost spool, you're going to have to accelerate the entire car faster (unless you're in neutral, but then what's the point?). Accelerating the car faster requires hp, which I don't think a lighter crank pulley is going to give you much of. Maybe a lighter crank pulley along with a lightened flywheel might make a noticeable difference.

 

Which rotates quicker and more efficiently? a 16" rim that weighs 20lbs or a 16" rim that weighs 50lbs. Both sides of the fence, I'd still have to see #'s before I'd want one. If the cash gremlin stays away this summer though, I'll take one (as long as you can prove they work hehe)

 

I see what you're saying, and it is true that a lighter pulley will require less torque to accelerate than a heavy one, but you have to consider how much torque is going into accelerating the pulley or flywheel compared to how much torque is required to accelerate the entire car. I submit that the amount of power that a lightened pulley frees up is diddly squat compared to the power needed to accelerate a 3000 lb car into a 14 sec quarter mile. People notice a difference when they rev the engine up in neutral after putting on a lightened UDP and get all excited, but they're neglecting the fact that it only takes 5-10 horsepower (if that much) to rev an engine up in neutral, so freeing up a hp or two with a lightened UDP makes a significant difference. But only if you're in neutral. Furthermore, the higher the gear you are in, the less effective a lightened pulley is, since the torque being freed up is proportional to rotational acceleration of the crank (T=Ia) - and the higher the gear, the less rotational acceleration you have. So a lightened pulley works best in 1st gear, but us SC'ed folks have more power than we can use in 1st, and sometimes in 2nd too, and by the time you're in 3rd gear where you can use some more power to the wheels, the power being freed up by the lightened pulley has diminished considerably. I guess the good news, though, is that the faster your car can accelerate, the more performance you can get out of a lightened pulley or flywheel.

But, cliff notes version is I don't see it as being a cost-effective mod.

 

The price of the pulley is ~ 1/3 of a nitrous kit... Hmmmmmm $perHP!!!

 

Interesting posts StephenMax, I just learned something new, although the concept is simple. I guess we will have to wait for some cold hard stats on this pulley to see if it's really worth the cost.

 

I have one the Orthodox makes...as soon as I get a chance I am, going to dyno befor and after.
I figure that I will dyno and tune my car with the factory pulley then I will just change out the pulley and see what I dyna at then.
I will keep you guys posted. I may by 2-3 weeks.

 

this lighter UDP would be a much easier install then dropping the tranny and swapping out the flywheel. The gains with the flywheel are very noticable. This UDP would be a cheaper be the best HP for the money and less work