Thank you for making my point

I just find it interesting that despite the part not even being out yet, you know the price, but not even UR does.

 

Z-1: do you know if UR manufacturers thier pullies in house or if they contract it?

 

# 1 - I never stated the price
#2 - My point and yours are completely diferent. You point was "gouging HR owners? That honestly makes 0 sense" and "The only more expensive item I have seen is the intake - and given that it's 2 x the # of components than previous, yes is less than 2 x the cost than most comparable intakes offered for the DE" which I clearly disagreed w/ it b/c the price of the HR exclusive stuff costs more ( as I stated on my previous post. )
#3 -You also made the point that "All the rest of the parts, from suspension, to brakes, to wheels, to aero (less the hood) are all the same anyway and work on 03 and up cars" Now, that I agree with, so if this is your only point, then I guess I did make your point.


I don't wanna start a war of words. The only thing I said in response to aloh is that don't expect the price to be the same, and if they can do it for the same price, well I guess we are all going to be Happy campers

 

After looking into this myself a little bit, i doubt that us HR owners will see the same results that the DE owners did from a underdrive pulley simply due to the fact that our stocker can't possibly weigh as much as the DE's stock pulley, so their will be less weight reduction overall. Seeing as the weight reduction makes up 85% of HP gains (according to UR), less weight reduced = less hp gained...i may be wrong but our pulley only has one belt on it, whereas the DE pulley had two from what i can tell, one for alt/water and a seperate for the AC pump. just my thoughts on it.

 

i see ur point BUT when i installed a undrive crank on my revup, the weight difference between the 2 was amazing. and lets just say that there isnt any weight diff, i would still buy an underdrive crank just coz its underdrive, i noticed a huge diff on my 06

 

you would need to ask them

 

how long do you guys think till there ouy

 

I'll ask Monday, I have to go down there anyway

 

UR really tries to play up that less weight = such and such HP per lb removed. It's so silly really. Yes, removing weight reduces moment of inertia and does technically improve performance. But you have to consider something, the pulley is less that 7" in diameter and it's mounted directly to the engine. When it comes to making gains from reducing inertial weight, one as to consider the location of that weight on the rotating part and how far that weight is from the engine. Take tire/wheel packages for example. Most of the weight is far from hub. The more weight that is further from the hub, the harder it is to rotate. Most of the weight on a tire/wheel package is over 10" away. Running a 45lb tire/wheel package vs a 55lb tire/wheel package will result in a gain of about 5-7whp on a Dynojet and slightly less than a .1 of second in the 1/4 mile, with much of the gain being realized in the first 330'. So basically removing a total of 20lbs of rotating weight from 10" away for the hub on the tire/wheels gains about 5-7whp at the motor.

Now let's look at the crank pulley. The stocker weighs in the neighborhood of 7-8lbs and is 7" in diameter and is mounted directly to the engine. Removing 4-5lbs from the pulley just isn't going to make that much difference at all because rotating height is very close to the hub. Think about it for a second, which is easier to accelerate: A 5lb weight on a 5' rope or a 5lb weight on a 1' rope? The same basic principle applies here.

There is a very elaborate physics formula that shows the impact of inertial weight on a rotating assembly and the power it gains/removes. Basically, something small like a lightened crank pulley is not going to any measureable effect on performance. The only thing you'll really notice is that the engine will rev quicker in neutral. Additionally, the gains from reducing rotating weight is entirely dependent on the gear you're in and the torque multiplication available for each gear. With each successive gear, the "gain" becomes less and less.

In the end, it's just another case of manufacturer taking advantage of people's automotive ignorance. UR isn't lying, but they're misleading people because the math isn't remotely as easy as they imply it is. I'll be happy to post up the math once G35driver.com comes back to life.

 

While you're right in theory... I'll let you be the one to tell the DE, E46 M3, and any other car that has measurable gains with pulleys that they are lying.

 

Say what?

 

Your points are valid about earning (freeing up) horsepower from something small and close to the engine - - but how can you deny the dyno'd gains from countless independent testers on cars ranging from the 03-05 Z and the E46 M3?
Pulleys CAN help the car regardless if it's just 1-2lbs less or whatever. I'm not saying they WILL help the HR - that I can't possibly know.

 

I've never seen dyno's for pullies on Z's/G's. If anyone has any links, please share. thanks.

 

you are forgeting the amount of underdrive creates power to, not just how much lighter it is.

 

updates?

 

yeah any updates...... been waiting for a while now

 

Hopefully UR has the complete set available sometime soon! Also interested & looking for updates.

 

crank pulley's will be available soon...no eta on full sets yet

 

Any estimates on power gains?

 

no idea