How much of a difference will they make? i'm thinking of getting the parental units to get them for me for xmas, but if they aren't going to do too too much, I'll ask for computer parts instead (also much needed, I'm on a 1ghz AMD ) Will they much the engine idle quieter under the hood? I love my Flowmaster, but it's wonderful sound sometimes gets drowned out (I went for tone > volume), and that's why I want to get an e-fan, to help keep noise down...

 

It shouldn't change the noise at all...you'd get maybe 8 hp or so...so that's what, about 1/10 of a second in the quarter mile, if that. You'd be better off with an e-fan.

 

Interesting. You think an e-fan gives more than 8 HP?

 

E-fan HP gains = minimal.
E-fan is good for hot days stuck in traffic.
Yet, I still want one.. but more for the experience of installing
Go with the UD pulley, you'll be happy. Install isn't bad and gains are felt instantly.
Price to Horsepower ratio is a lot better you'll find most anywhere else.

 

I'm not sure exactly what it'd give you but I remember in my Jeep it feeling like a good bit right off the bat (probably somewhere between 6 and 8 hp). What's better is that you can control when you want it to come on and off too if you hook it up that way, you'll get some gas mileage savings, and you'll also reduce the noise, which the OP is interested in doing.

 

i did the efan then pullies. i did the efan first to get rid of the horrible mechanical fan noise. i noticed that the engine revs soooooooo much better without the mech. fan. i think the pullies had more of a seat of the pants difference, but the efan makes it much easier to get the rpm's up to where the truck needs them......3000+. i think the best feeling thing i've done so far is the jba headers in terms of power and sound. oh i did the efan first to make it easier to put on the pullies also!!! now its time for a tuner.....

 

Just be advised that your alternator capacity goes down. Shouldn't be a problem UNLESS you have a lot of aftermarket electrical equipment that has to run at idle like lights, winches and so forth.

You can get smaller pulleys for the alternator, but sometimes it's just not quite enough.

I took my underdrive pulley off, but left the smaller pulley on the alternator to get a little more charge at idle since I have a winch and all.

 

the pulley kit from underdog comes with a 20% overdrive pulley for the alt. so it charges the same as stock!

 

Indeed -- but that presumes STOCK charges enough, lol -- which i my case I didn't feel it did. I don't recommend underdrive for anyone that offroads a lot who runs big lights and/or winches, even with the "compensating" pulley -- in fact, sizing down to a compensating pulley without putting on the underdrive can be a distinct advantage in those situations.

 

maybe not gives, but it doest give back alot... never drivin with the UD pulley but the efan was sweet while i had it...

 

n3elz , aren't there also higher output alternators available out there somewhere? i'm sure i've seen them at some point

 

Yes, but interestingly enough they can make the problem WORSE.

Generally, they are wound differently and though capable of higher output, they generally require more RPM to get it, assuming the same case size. This has bitten many folks who have upgraded. They may actually get less output at idle than they did with the old alternator.

I went to a 200 amp, large case 3G alternator (which JUST fits on a 3.0) and that helped a lot -- but with the smaller pulley I get quite a bit more output and still keep the alternator below 20,000 RPM or so.

I don't hit the redline ever in my truck (generally doesn't go much past 5000 with a max of around 5500) which is why it's okay. You don't want to do this on a race vehicle though with the RPM limiter removed, lol.

 

thats sounds alright to me, cause in addition to power mods i was also lookin into high output alternators if I end up adding lights and a winch (down the road), I don't plan on doing anything to the rev limiter which being an automatic i believe is between 5000 and 5500