lightweight pulleys, power gains?

[spazzkid]

anybody of u used one of them lightweight pulleys (made of aluminum ata),
ive read of one of them tuner magazines that it --"increase horsepower by decreasing the parasitic effects that factory accessory pulleys have on a vehicles engine.-- eg, aircon".

http://www.eautoworks.com/html/ape-a...ulley~Kits.htm

are these worth it? are the power gains significant? howbout slapping it on 1.3l engines?

[ssaloon]

kung stand-alone lang ang application, feeling ko negligible power gains. but if you have tweaked internals, e.g. increased compression ratios, aftermarket pistons and cams, etc. siguro malaki ang power gains.

i could be wrong though... paki-tama nalang kung mali ako

[spazzkid]

so it has to be used in conjunction with other engine mods?

[yebo]

just think of it this way...

lightening your flywheel (which is considerably heavier than all those pulleys put together) results in negligible increase in power output AT ACCELERATION. during steady engine speed there is no gain whatsoever (3rd law of physics. the rotating masses - pulleys, flywheel - does not contribute to the creation of energy, only in it's conservation).

a big flywheel when lightened results into negligible net power output since there is less mass that will absorb the power from the crankshaft.

how much more a lightened pulley? less than negligible is very close to zero.

conclusion: waste of money lang yan.

[ghosthunter]

Underdrive Pulleys gainback about 5hp from a typical 1.6 engine.

Lightweight pullies... minimal. Better to lighten the flywheel.

[Gian]

If you're really after maximum gains from the pulleys, you don't you try disconnecting the belts connected to the aircon and power steering; libre pa! :D

Yun nga lang, you have to put up lang with the inconvenience of not having AC and power assisted steering.

[Karding]

Originally posted by Gian
If you're really after maximum gains from the pulleys, you don't you try disconnecting the belts connected to the aircon and power steering; libre pa! :D

Yun nga lang, you have to put up lang with the inconvenience of not having AC and power assisted steering.

yan ang magandang alternative kung pulleys nga lang ang ilalagay mo sa auto mo. ;)

and I couldn't agree more of what yebo has posted.

[spazzkid]

so it looks like its just marketing crap.

[Karding]

Originally posted by spazzkid
so it looks like its just marketing crap.

exactly some manufacturers reports a HP gain but doesnt report the buyers that the dyno was done along with all other performance parts intalled on the engine.

[Wolverine]

Actually, I have used and continue to use a lightened pulley on my vehicle (lexus sc300 turbo) and it is not true that they are worthless. they do minimize parasitic loss and they are significantly lighter than the stock pulleys installed in your vehicle. In my case, the difference was significant. 10 lbs and 7 ounces for the stock pulley and matching harmonic balancer vs. 1 lb and 5 ounces. As far as I know, it is quite difficult to shave 9 lbs of material from your flywheel. Furthermore, if you do manage to do so, you will affect the driving characteritics of your vehicle significantly where your acceleration may be quick but sustaining momentum is compromised. The same cannot be said about a pulley upgrade. It would be too hasty a judgement to say that they are a waste of money. Go check http://www.unorthodoxracing.com
They post dyno charts that specifically state that the tests were done both prior to the addition of a pulley and after. You might be surprised. A modified 300zx gained 37 hp and 45 ft/lbs of torque on the pulley modification. There are other vehicles posted there too so it's not exactly fair to say that these manufacturers post hp gains but fail to mention that there were other mods done along with the pulley that they are not disclosing. Of course, the higher your base hp, the more significant the gain. Ganun talaga yun.

[Wolverine]

to add....if you are just going to change the accessory pulley, I agree, that this is a waste of money for there are only negligible gains if any. By the way, the idea of removing the A/C and power steering belts is too high a price to pay. Why would you want your vehicle's comfort features to suffer besides, the stock crank pulley will still be attached to your alternator and still drain power regardless.