I was bored today and since it was such a nice day (78 degrees:D ) I thought it would be a good day to take the underdrives off the 87 and try em out on the 86. I took some pics along the way... (I'm such a camera w, heheh) I didn't change out the alternator pulley, only the crank and water pump pulleys.
There seemed to be a seat of the pants difference with the change. The engine seemed to be more responsive and rev a little quicker. It didn't affect the coolant temp at all and the stereo was fine with the lights on. The dash lights would dim a little with the turn signals though (who cares).
Here's a pic of the water pump pullies. The big one is the underdrive.
(http://i2.tinypic.com/6ta2icy.jpg)
The underdrive crank pulley is the small one.
(http://i1.tinypic.com/71wnm01.jpg)
And finally, the tensioner stayed within range with the stock (for my config) belt.
(http://i6.tinypic.com/6q9ppw5.jpg)
This is pretty basic stuff but I figured somebody might find this info useful someday. Also, you dont have to remove the fan shroud to do this job. Just leave the belt on to break loose the fan and crank bolts.
sorry, i do more restoration on my car than modifications... and this is prolly a "newbie" question... but what exactly does an underdrive pulley do? i mean isnt the crank > cam a chain? and all other accessories run off the pullies? i mean im lost in the concept! can ya help a simpleton out?
slows down the accessories so they have less drag on the motor
The underdrive pullies slow down the BELT driven accesories. The small crank pulley reduces the speed at which the belt is being spun by the crank and allows the engine to spin more freely. The larger water pump and alternator pullies that come with the kit reduce parasitic drag by further reducing the speed of those accessories. They've been pretty well proven to increase HP across the RPM band by 7 to 9 HP.
I think I got that right.
I have one of these on my Mark vii and even with a 4,000lb car you can still feel improved pull of the line. Add a K&N filter to add even more.
:burnout:
i don't have a system or anything, but i have a nice head unit and decent component speakers (the head unit made the biggest difference in sound quality, for 500 bucks it better) so would this screw that up at all? what if i complimented the under drive pullies with a alternator upgrade, would that make up the difference if there was one? (also so i dont get any dimming what so ever?)
I've got two 300 watt alpine amps and I have no issues at night with all the lights on. However, it's important to note that I'm using the stock alternator pulley and I have the 3g alternator upgrade. I'm not sure if it's the 95 or 130 amp version though. The car already had it when I bought it.
(http://i10.tinypic.com/6wnyxbq.jpg)
On my 87 bird I had a stock alternator with all 3 underdrive pulleys installed and had no problems with my Pioneer DEH P4600MP 50X4 Mosfet head unit. Turn signals seemed to be the biggest drain and even that was never a problem.
O.K.,I'll go to Ebay and pick up a set asap.You talked me into it.
I could use 7-10 ponys!!
Update... I am having charging issues at idle with the stereo cranked up. The tach will start bouncing all over the place and if I turn the lights on the tach dies. It cant handle those two amps at full power at idle. And the alt is the 135 amp 3g.
The jury is still out but if it gets annoying I lose the crank pulley and just leave the water pump pulley on. So if you have a high power stereo I'd think twice about installing pullies.
My battery was on it's way out and I had corrosion on the positive battery cable at the terminal end. Once I bought a new battery and fixed that wire I have no more charging problems.
I run MARCH underdrive pulleys on my cougar. regular old 2g alternator. ive never had any problems. highbeams on, windsheild wipers goin, radio on, radar detector on. never had any problems. sure a 3g would be better, but i dont see any need for me to switch if everything is still working fine.
Question for you all.
I talked to several vendors and they said that the mustang underdrive pulleys won't work? So what did you guys/gals use?
I don't see the difference in a Tbird/cougar 5.0 and a mustang 5.0. My bird is an 88 and a masterpiece in the working.LOL
Mustang underdrive pulleys work fine unless you got 3 amps but can be fixed as easy as a 3G swap after that.
Got a BBK set of my old motor and the new car i just bought only has 1 underdrive pulleys and not a full set.
So as long as you don't have a massive car audio set-up go order you a set ASAP.
Since the crank turns all the accesorys I got a crank u/d pulley and im gonna run just that and see what that does.
daboss351. let me know how that works for ya. The spare engine I have has just the crank UD on it. I don't have the full set so I was thinking of just throwing stockers back on it.
The Crank pulley is probably 80% of the benefit... In fact my set came with a same size diameter water pump pulley and a slightly larger alt pulley, which I never used... Seen some alts with a factory pulley same as was included with mine... No I don't remember what brand my set is, bought 'em back in '94 for a 5.0 Stang...
Thats what I wanted to hear!! I got a killer deal from a local member on the pulley, and I only got it cause I used logic, and figured that would be the biggest part of it.
so what brand is everybody getting? march? aluminum or
steel? had a set on my gt mustang and 93 f150 years
ago. both were march.--irv
Dogcharmer, I believe your problem is your stereo not your pulleys.
Someone back me up here but didn’t the 93 cobras come stock w/the U/D crank pulley but not the alt or the waterpump.
mines aluminum no idea the brand, bought it used
Ive been selling underdrive pullies for 85 and up 5.0
Mustangs since well they first came out in the mid 80s.
Kaufman Products made the original design back then.
We put them on a boatload of Stangs back then...
But most people just ran the Crank and Waterpump pullies
and tossed the alternator pulley in the trash.
The smaller crank pulley would enable the crank to spin
faster, while the larger water pump (and alternator if you
chose to install it) would slow down the accessories a bit.
This would release whats known as Parastatic Energy.
Either way, its a good idea to a point, but if you slow the
accessories too much, you can run into a cooling probelm or
a charging problem from your alternator/battery.
The overall gain was maybe 3-5 hp on a good day, but they
seemed to help and in theory they do work.
Move on to the late 80s..we had a customer come in with an 87
5.0 Cougar who wanted more hp. We installed the 2 pcs only
pulley kit (crank and w/p pulley only) didnt want any charging
problems, on the guys Cougar.
He came back a few weeks later and it was weird, he came back to our
shop and demanded to know what all we did to his car. At first I
thought he was mad, but once I convinced him all we did where the
pullies, he proceeded to tell me his gas mileage went up 5-7 mpg
in town !! The Hp gain was fair, but couldnt get over how much his
gas mileage went up.
And since then every Bird or Cougar and Lincoln we put the 2 pcs pulleys on, always had the same or very similar results.
Funny thing is, the results where never the same on the Mustangs.
The only difference I can think of is that the Mustang has an 9 blade fan and our cars have 7 :confused:
visually that may be the only diff
could have to do with gearing, weight,
ecu maps that have to do with timing curves,
hard to say ..
the end results where always the same
Mine now has a 9 blade with no difference in fuel economy.
Only driving 400 miles a year how can ya tell? :rollin:
I haven't had to fill it up more than last year;)