Ive got an underdrive pulley for the crank, its the Motorvation pulley. Is it going to affect my power output from my battery, I have a fairly big audio system, it was ok with the stock pulley but is this smaller crank pulley going to affect it. I was told that as long as the alternator pulley is the stock one then it wont affect it much. Thanks

 

I know someone has the answer to this question.

 

If you don't get a fast response, try posting in the audio section and maybe the lounge. Hope this helps.

 

You can get a larger alternator pulley, this will allow your charging system to stay the same while reducing the rest of the system (power steering, AC compressor). I don't think you're going to see much in HP gain with the underdrive pulley so you may want to leave the pulley system alone.

 

A larger alternator pulley slows it down, a SMALLER one speeds it up...
Most people put the smaller one to compensate for the slower alternator speed, if it doesn't charge right..
Some UD pulleys come as a kit that has the smaller overdrive alt pulley in it..

 

From the dyno sheets I've seen expect:
[1] One hp at high rpm
[2] 2-3 hp over the "curve".

Is that's worth $100 - $130 to you ?

 

My bad...as stated above, you want a smaller alternator pulley.

 

As far as UD pulley's, I've heard that the only one worth getting is the ASP pulley. It's not a piggy-back like all the other pulley's, it's a direct replacement of some sort...

Anyone using one?

As for robbing power with the UD pulley and having a big stereo system, you could always just pick up a 1/2 farat or 1 farat capacitor...it'll draw power for your stereo at high RPM's and will use that power when you're sitting near idle...that way you won't be overworking the alternator...

 

I have the integrated ASP pulley/damper (I think it's 24% underdrive) and a moderate-wattage audio system (~100Wx4 + 300W sub). At normal to loud volumes the needle stays above half. If I really pound the sub the needle will drop to the top of the red as it hits.

But under normal driving/playing, it's fine.

The car noticeably pulled harder in 2nd gear with the pulley, and seems to rev up a bit quicker too.

 

So you'd say it's worth it?

 

The version I bought, definitely. Model 945100 (945103 includes an underdrive alt. pulley too). I wouldn't buy an add-on version--more weight on the crank to spin.

Another added benefit is it spins the power steering pulley slower, which extends its life and keeps it from boiling over as much.

 

You need to get the alternator overdrive pulley with that system, they are $20 from thunderracing, and it took me all of 2 minutes to install.

 

I have the ASP pulley also. IMO, it's the only one worth buying. All the other ones are stack ons and add on extra weight. I noticed a difference right away and the car seems to pull harder and quicker. It does seem to put some strain on the alternator but nothing serious. I've had mine for a month and the car feels fine during normal city/ highway driving.

 

I know the ASP is the really the only way to go and is the only one I would even consider. The dyno referred to earlier was with a March "piggyback" style pulley. I have never seen a dyno of a before and after ASP pulley, does anyone know of one? The ASP pulley is just so expensive, I need to really be sure its worth it.

 

I haven't seen a dyno comparison of the ASP yet (they do make add-on styles too), but here is another dyno comp. of the Hypertech pulley.

http://www.ws6.com/mod-2.htm

The average gain is important, which is about 5hp and 5tq throughout the whole RPM band.

I imagine the ASP combo would be closer to 10, but who can say for sure!