Would it defeat the purpose of underdrive pulleys if.....

[DaveL]

I overdrive the alternator pulley?

 

[85GTlover]

Some suggest leaving the alt pulley stock just change others. Your idea

 

[wytstang]

I thought about that as well. I want under drive pullies but later would like a nice sound system so that idea crossed my mined too.

 

[AznStanger3v]

i left my alternator on there. i just didnt want any charging problems. then i went out and bought a high amp alternator, but the pulley stays.

 

[fawcett]

I have the March Pulleys on my 95 gts, my stereo and projectors dim down when it sits at idle. i thought an optima battery would help, it didnt. im considering putting the stocker back on my alt. to fix it.
just my 2 cents



fawcett
95 Gts FRPP Crate 340hp 302 e-cam
24lbs, aeromotive fpr, 65mm frpp, pro-m80, track heat intake, mallory digital ignition, saleen heat extractor hood, cobra r's, brembo's all around etc etc etc
13.5 103.6 on street tires
Plus I Roll Wingless

 

[GTPhreak]

i run a overdrive pulley on my alt along with asp underdrives on the crank/water pump. seems to still be good

 

[JJ95GTID]

Just leave the stock alternator pulley on when you install the U/D pulleys. My alternator would not charge below 800rpm (idle) with the U/D pulley. Put the stock pulley back on and no problems at all.

 

[viperos]

well, a few bits of knowledge from the peanut gallery

-first, the alt pulley w/ the UD pulley kit is an "overdrive pulley", it is bigger than stock...

-but to answer your question, it will diminish the performance of the pulleys by leaving the stock alt pulley on it... although you won't run into charging problems (not that I have any at all, just slightly dimmer lights at idle... ) the power results have been dyno proven (by a guy w/ no life, too much money, and time ) and showed by several pulls that w/ the new alt pulley, it completes the system, and gives you some more power (but keep in mind, it's only about 1-3FWHP, very marginal... so, it's all up to you... personally, I ran the new pulley...)

-sorry for the long post, but figured I'd give you what I knew on the subject

 

[greg@berkeley]

first, the alt pulley w/ the UD pulley kit is an "overdrive pulley", it is bigger than stock...

that's not true. the pulley is bigger, thus it spins more slowly (i.e., it is underdriven compared to stock).

no flame, just wanted to clear that up.

 

[281pony]

so to clarify. i have some rockford amps/jl sub/6x9's ect, and a 3g 200 alt amp. so i really dont need charging issues

if i bought underdrives, and didnt use the alt pulley included, i would maintain the gains of the pulleys except for about 1-2 rwhp of the 10 you gain? and not have the charging issues?

 

[Adrenalin]

On my coupe I had the small race crank pulley and had major charging issues. I then bought the ASP (race crank altenator) pulley, which was used for when you had the super small race crank pulley, and it still didn't charge as good as I wanted it to. Then I changed to the regular underdrive crank pulley and had no problems with charging and had an amp in the car as well. The car ran 11.4s @ 119

 

[DaveL]

Thanks for the input guys. Since it's easy to swap out I'll put the stock one back on to and see if I can feel or see the difference.

 

[go.rei GT]

I've seen two dyno sheets after just installing the crank+water pump pulleys (stock alt.) and they netted 8whp and 9whp respectively. Until I get a new daily driver, that's good enough for me...but when I do, the alt. will get switched too.

 

[rudeone707]

I have had my pullies on for about 4 days and notice the voltage go down a little bit at night. But its not really an issue. Just throw a rev or 2 at a light and your good to go. i think my pully set said that it had max charge at 950 rpms

 

[wytstang]

I have had my pullies on for about 4 days and notice the voltage go down a little bit at night. But its not really an issue. Just throw a rev or 2 at a light and your good to go. i think my pully set said that it had max charge at 950 rpms

Do they work as good as everyone say they do. I'll probably order mine sometime next week ( asp )

 

[Adrenalin]

Underdrives and Gears are about the 2 (cheap) best bangs for your buck imo

Underdrives have been the first thing I have started with on my stangs.

 

[rudeone707]

Do they work as good as everyone say they do. I'll probably order mine sometime next week ( asp )

i havnt really went WOT in the stang since i have put them in. I am still looking for a noise in my car. I think Joe (vibrantredgt) dynoed at like 8 rwhp.

 

[viperos]

ummm, aren't underdrives and pulley the same thing??

-and CAL - greg@berkley, no problem... temp. lack of mind but the point is, I DID KNOW they were different sizes

 

[stunner6910]

charging should not be an issue. my car is bone stock and lights still dim down at idle. i had u/ds with two amps and 10" subs with no problem in my old stang

 

[95snoozer]

oops