5.0 Mustangs Tech Forum

Mustang5oh · 09-09-2002

I just bought a set of underdrive pullies for my 90 Fox GT. Was wondering if anyone could help explain the procedure for putting them on. Or any tech articles you could send me to for information. Also wondering about if a different belt size or anything like that is needed. Any info is appreciated.

86StangLX · 09-09-2002

If you ordered your basic set of pullies (crank, fan, and alternator) then you shouldn't have much of a problem. The crank and fan pullies are removed with basic tools. The alternator however requires an impact wrench to get it off. If you own an impact wrench, you'll be fine... Otherwise, you may have to take the entire alternator out, and take it to a shop that can swap the pullies. The other two come off just fine after you remove the belt. Oh, and no, you won't need a new belt. At least I didn't... Unless you're running dramatically different sized pullies. The stock 90" should fit.
Paul

Mustang5oh · 09-09-2002

Thank you very much. I will get right on that shortly, possibly this weekend. I have had them for about a week so I'll be glad to get them on and see how she runs.

Thanks Again!!

Have one on me

09-10-2002

Those pullies will bother the hell out of you later on.

Mustang5oh · 09-10-2002

Just wondering why you say they will bother me later on. i realize they draw power from the accessories but just wondering if you meant anything specific. something like ruff idle or headlight dimming problems at idle.. i heard some people talk about those, jsut wondering what you meant.

09-10-2002

I never had them on MY car but have had some friends who regreted they put them on. ("later" in life) Your car WILL run faster, but **** starts to break after awhile. Why? The point of pullies is to Speed Up the engine quicker. You do the math. I never wanted them on my car. I was also warned not to put them on my car. I was still beating newer camaros etc without them so I didnt bother. I would reasearch over the net the benefits and draw backs of pullies. Then you decide what is best for your car. Dont let me worry you, they will work great, but IMO, I never wanted them.

GhostDog 5.0 · 09-10-2002

I would leave out the alternator pulley. Not that much of a boost from loosing just one pulley.

Plus it's easier to install since you dont have to yank off the alternator. You can always sell it on ebay too.

Vortex · 09-10-2002

not on the anti-pulley side, but im not using them for a reason...
1) I dont want to put that much of a load on my alt... less output + same draw= wears quicker... not much... but it does
2) Im getting an electric water pump.. not much point there..
3) Im getting a centrifugal supercharger.. an underdrive crank will slow down the super and produce less boost...
otherwise a crank underdrive would be good..

1QWKSVT · 09-10-2002

I have them. It's not really worth the gain. I didn't notice much of a difference when I put them on. My car runs a little warmer when it's hot out and your headlight's won't be as bright when your not moving. If you put them on with an impact wrench be careful when putting on the alternator pully! You can mess it up, my buddy pulled the shaft out of place and we had to have it repaired

spyder · 09-10-2002

agree with adam. under-driving my water pump just isn't something im comfortable with, that and under driving my alterator too??? all for a few HP that you will not feel, and for those who say they do, changes are its just their imagination or them steppin on it harder after installation. save the hundred bucks for something else more productive.

Mustang5oh · 09-10-2002

Thanks everybody, I've done some researching on my own recently and decided my best bet is to sell them and go for 3.73's instead. Rather spend the $$$ on something I'll notice. Thanks again

spyder · 09-10-2002

good call. quick questoin, i see you have an x pipe with the same flowmaster system. did you notice a interior noise difference when hookin up the x pipe? did it stay the same inside or get louder? how about drone....thanks , im lookin into an x pipe for spring. just gatherin info

Mustang5oh · 09-11-2002

The interior noise didnt change much with the xpipe... a little more of a mellow sound but not really louder. but all my friends told me the exterior noise was a much nicer, rumbly sound

GT Dan · 09-11-2002

Rebel Dan here.....I have to disagree.....I got pulleys put on my car. I did notice some difference on the top end. While it wasn't a huge difference there was some. I did it.....I experienced it and I'm not Net-hip shooting.

I do notice the lights running a little dimmer at idle and I just rev the motor a tad when putting my power convertible top up or down. My car has gotten warm a couple of times when the outside temps here got over 100; however, I attribute that to other factors and not the speed of the pullies.

If you are going to have a N/A car I would recommend them. If you are planning on using forced induction, then use the recommended pulleys for the charger techs.

fvpnt0pony92 · 09-12-2002

what are you guys all whining about...how many of you who said underdrives are bad have actuallu had them? i have them, my car doesnt run any hotter, the is only slight charging problem at night when im idling....the solution is too rev up the engine 200 rpms or so. my car has never died because of the low charging though....so what the big deal?!? why are they so bad?

i also noticed more power, not much but for 15 minutes of work it was worth it! so basically dont give advise opn parts if you have no experience using them yourself!