Poll question: Okay guys, one of my friends, and myself would like to put a UDP on our cars...we can't decide which is more important, please help us out...lightweight vs underdrive...which do you think unleashes mo

Poll result (12 votes) AF/X 30% underdrive (11 votes) Vote Unorthodox lightweight 15% underdrive (1 votes) Vote (0 votes) Vote (0 votes) Vote (0 votes) Vote (0 votes) Vote

ummm...yeah...that was supposed to say, "...unleash more power..." Anyways, I always wanted the AF/X, but now I'm wondering if the lighter wieght would be a good idea...thanks for the input guys!


2gnt.fullwormage.com/files/apexiexhaust/

i think more gains are had from the underdrive than the weight. even so i cant imagine the unorthodox weighing much if any less than the afx. it is the same material and would have a larger diameter.

>i think more gains are had from the underdrive than the
>weight. even so i cant imagine the unorthodox weighing much if
>any less than the afx. it is the same material and would have
>a larger diameter.

Exactly!

another thing you need to consider for an underdrive pulley is that the accessories will turn slower. this is where the horsepower increase comes from but if you have a system or other electronics in your car the alternator may not put out enough energy.
-drew

I didn't think the UNorthodox put out a 15% underdrive? Thought t they only had 20% and 30%

Both pulleys are aluminum, so weight per size is going to be the same. So a larger 20% underdrive will weigh more than the 30% AFX.

If you are worried about voltage, which only at idle do you see any voltage that drops at all from 14 volts. Get a different pulley for your alternator and spin it back up.



15.9 @ 86.7mph

Injen CAI, 55mm TB, P&P Intake, Crower Cams, Hooker Header, ERT/Catco Cat, GS-T Muffler, AFX UDP, Crane Ign Amp, S-AFC

>If you are worried about voltage, which only at idle do you
>see any voltage that drops at all from 14 volts. Get a
>different pulley for your alternator and spin it back up.


But wouldn't that defeat the purpose? Not being a dick, really curious.

I don't think so. I mean you are still underdriving the crank the only thing you are overdriving is the alternator. Really not sure though!

Anyway, I chose the Unorthodox and I am happy. Plus I trust that company more!

http://www.unorthodoxracing.com/ultras.html
Power gains are obtained in two ways. First, and most important, is the weight loss. An average of 2.7 HP is gained from every pound lost off the crank shaft. 85% of our gains are from weight loss.

The rest of the gains are from underdriving, which accounts for about 15% of the total gains. We do not push underdriving for two main reasons. Our main reason is to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving. Second, not much horsepower is gained from extreme underdriving. In most applications all of our underdriving is done with the crank pulley, not the accessory pulleys. This is done so maximum weight loss can be achieved at the crank where most of the horsepower gains are found.

Jersey, where did you get that statistic...

...so, I'm still weighing the options...IF the unorthodox pulleys are like 1 pound lighter, overall, would that 2.7 HP be greater than the extra 15% underdrive?


2gnt.fullwormage.com/files/apexiexhaust/

i would say the unortodox is a nicer piece, it is 2 piece unit, the afx is alright, but if you have any demands for power over stock then you will run into a alternator output problem at idle.

lates
james

I don't see the overdriven alternator being a problem. Here's my reasoning.

The alternator creates resistance to produce current. The new smaller puley is lighter, so you reduce rotational mass. As you spin at normal speeds the voltage regulator governs how much resistance is put throguhh the alterantor to produce the proper voltage. I think the lower mass of the smaller puley, is more benefitial than underiving the alternator.



15.9 @ 86.7mph

Injen CAI, 55mm TB, P&P Intake, Crower Cams, Hooker Header, ERT/Catco Cat, GS-T Muffler, AFX UDP, Crane Ign Amp, S-AFC