I've been thinking about getting an Underdrive Pulley, but I have some concerns about it. I remember reading somewhere once a great while back, that putting on a underdriver pulley with a large audio system is bad? I guess the alternator can't handle the load with the engine speed running slower. Any comments to this? I really don't know, I would just like some good clear facts about it, so I can make a smart decision about my mods. Thanks.

 

My car does not have any aftermarket stereo, but the underdrive pully works great. I gained 14rwhp/12rwtq with it. No charging issues at all, even with city driving.

 

I like those numbers...alot actually. But I'm pushing about 1000, maybe 1500 watts, with no capacitor, so thats why I'm wondering about the underdrive pulley. My lights already dim alot with my system on, even running higher rpm's.

 

with an aftermarket system there is no way you can run pulleys. Even with the overdrive alt pulley. Either the stereo or pulley but you cant have both..maybe you could get a second battery.

 

Ditto.

 

Looks like the pulley is out of the question...unless I upgrade the alternator..but then that will cause more parasitic drag, am I right? From the looks of it...no pulley.

 

I have 2 amps,2 12's and a cap tube,+25% underdrive pulley.
no probs at all.even idle w/ ac + stereo cranked you just have to set your
idle to 900 in park. (i had to with my stall converter anyway)
the lowest the volts goes is 13-13.2 tap the gas it goes back to 14.2
hope this helps, ken

 

or you could just upgrade the alternator to a high output one that way even at lower speeds it will put out the same as your stock one. But to me it sounds like you have overloaded your system already. from what I hae read you should be using a .5farad capacitor for every 500wattsRMS so if you really are pushing 1500watts then you would need atleast a 1.5farad capacitor

 

Yea....I haven't put the money into the cap yet lol. Looking at getting a 2 farad because I'm also about to add another amp for my type R speakers I'm putting in the doors. I was thinking high output alternator....It wont cause more parasitic drag? Maybe adding those two things, and then the underdrive pulley will be 100% fine.

 

sounds like alot of trouble for more power and speakers..

 

Thats why I'm just thinking about scratching the idea of the underdrive pulley. Unless someone has first hand experience doing pretty much what I'm planning on doing....I'm not sure what to do. More than likely I'm not going to do the pulley, just get my new amp, and a damn good cap. Thanks for the help though.

 

what brand do you have?

 

I'm running over 1000 watts, have an underdrive pulley, and drive my car everyday. You don't need a cap. They are useless. A decent alternator and upping your idle and you'll be fine.

 

Yep, theres always a way!

 

Get the optional alternator pulley, and you will be all set.

The WS6Store sells them.

 

its an SLP

 

So with a larger alternator, I'll get rid of the dimming, and wont have the charging issues I might have with an underdrive pulley? Or use the overdrive alternator pulley, then the underdrive crank pulley...increase my idle and I'll be good?

 

well if you still want the pulley...yes get the overdrive and up your idle...to help your lights..just get a second battery, caps are useless, or you can get a bigger alt..but whatever suits you.. go to a specialty stereo shop, and they will know what will best suit your needs..

 

also without a bigger alt or extra battery, your lights will always dim with that kind of power...

 

Hmm....I'm kinda thinking about just not worrying about it right now. I don't have the money for all that, and I'm gonna be need tires real real soon....so I have to save for the rims I want as well. But thanks for all the input, when the time comes I'll just get a larger alt, overdrive alt pulley, and the underdrive crank pulley.