ok...
i need some info here... i would like to know out of all the 2.4 lightweight crank pulleys...which one is indeed the LIGHTEST.
RSM racing (the underdriven one)
unorodox
bomz racing (found on ebay)
rk sport
md ld9's
also i think theres a company called "top fuel" or something that makes one...
and if there are any more can someone post them up as well..
thanks a lot.
White 98'Z-alive n kickn
Black 97'Z-down for the count
Lightest from what I measured:
Underdrive:
RSM 11.2 oz.
Unorthodox 14 oz.
Ebay Generic from postings online smething like 1 lb 9 oz.
2.3L underdrive about 3 lb
Stock sized: (taken from memory)
RSM 21.6 oz
MD LD9 24 oz
APEX I think was like 27 oz or so.
So there you have it.
-M
Remember....syringes go in the RED waste basket.
Under-drive:
RSM 11.2 oz.
Custom Cargrills 11.2 oz. major underdrive.
Unorthodox 14 oz.
Ebay Generic from postings online something like 1 lb 9 oz.
2.3L underdrive about 3 lb
Stock sized: (taken from memory)
RSM 21.6 oz
MD LD9 24 oz
APEX I think was like 27 oz or so.
Stock crank 63-64oz.
I believe mastin is pretty damn close on all the numbers. Also added a few.
I would steer clear of RSM and/or Z-Spec, but maybe you will have better luck than other have had.
All the rest besides the e-bay pulley seem fine.
P.S. Pick mine
Edited 2 time(s). Last edited Monday, October 23, 2006 10:38 AM
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
I got lucky a year and a half ago and got the RSM Underdrive and the Stock size (lightened)
I'd just like to remind everyone that it's not neccesarilly which is
lightest, but which has the most optimal weight distribution. While going by overall weight is a starting point, it's the weight distribution that actually makes a difference.
eg. if you have a pulley with 2lbs right at the hub, but only 6oz around the edges, it will take less power to turn than a pulley with only 15oz total weight, but 2/3 that concentrated around the belt area.
Obviously, design is limited by stress and FEA, as I'm sure Mr LD9 dealt with during his design, so different high-quality pulleys are normal pretty much the same in terms of distribution.
fortune cookie say:
better a delay than a disaster.
OHV is correct. Designing a flywheel is the best why to explain it. If there is a lot of weight towards the center of the flywheel, and there is less stored energy then if your have a lighter flywheel with most of its weight at the rim of the flywheel.
Equation from machinery handbook. This equations is to determine the flywheel rim weight necessary to supply a given amount of energy in foot-lbs.
W=(E1/(CD^2R2))
W = Weight in pounds of flywheel rim
E1 = Energy given up by flywheel rim
C = Speed reduction table as given in table below
D = Mean diameter of flywheel rim.
R = Maximum allowable speed of the rim
To sum all this up. Two equally sized and equal weight pulleys with one having greater density at its rim, and the other having greater density at its center...do not require the same amount of energy to spin them. The pulley with its density towards the center of the pulley will accelerate faster then the pulley with its density towards its rim.
You could also think about 14 inch rims and 17 inch rims. Most people know that at the track your car WILL run faster with the smaller rims. This is because, most of the rotational mass is inside a smaller radius, and in turn WILL allow the vehicle to accelerate faster.
I hope that all made sense to everyone.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
