underdrive pulleys...good mod?

[Kilgore Trout]

And now is the time on Sprockets when my monkey dances while I post this:



TSB #14520
4.6L 4V Pulley Instructions
Some 1996-2001 Mustang owners, for engine performance purposes, are adding a special front drive pulley kit to reduce front accessory drive speeds. When removing and replacing the crank pulley, if the large bolt used to hold the crank pulley undertorqued, the keyway will shear and cause major engine damage. The resulting engine damage is not warrantable. If the crankshaft pulley bolt is removed it should be replaced as it is a torque to yield bolt. The installation of the crankshaft pulley requires that a specific torque operation be adhered to. The crankshaft pulley bolt must be installed using these 4 steps: 1) Torque to 75 lbs/ft 2) Back out one turn 3) torque to 45 lb?ft 4) continue to tighten and additional 90 degrees.

 

[007]

So get it installed by a decent shop if you cant do it yourself. Mine cost 50 bucks for install by a 100% mustang shop.

 

[chimchim]

I have a '97 with all other mods in sig. I had the car dyno'd at one shop after the headswap and I got 249hp. I had the car dyno'd after my tune and 4.10's (at another shop a year later / both Dynojets) and I got 237hp.

I had a leaky front cover, so I fixed it and installed Steeda pulleys since I had everything apart. I had the car dyno'd recently during a dyno day (at the same 2nd shop where I got 237hp B4) and it put down 246hp.

SO, same shop to same shop, SAE Corrected #'s with no other mods, they got me 9hp.... and it feels about like 9hp, too. The motor revs up a lot smoother and freer than it did before. $180 / 9hp = $20 per HP. HP don't come much cheaper than that!

 

[mustangkid05]

so pulleys are a good mod im guessing......when you guys say that it messes up your battery, that means the lights dim and stuff?

ted

 

[streethorse]

Get the Steeda (steel) under drive pulleys.
Have a professional do the install, as it takes air tools to
do it right, less than $100 labor anyway. I have an Optima
Battery and have no charging problems at all. Over 2 years. They kick a$$

 

[steveb24]

yes. i noticed a difference and installed them myself in under an hour, and i know not much when it comes to cars. just get a pulley pull from auto zone and a torque wrench

 

[Black Stang 97]

yeah, i say they are very worth it.i just got the steeda ones and they got me 13rwhp i did a dyno test before and after....

 

[soarin00gt]

the main thing is when you have a powerful stereo or something that it will drain the battery significantly, the alternator can't keep up because it's being spun slower (especially at idle).

Even with the stock mach460 and the a/c going I notice it will dip enough on mine.. I can't imagine someone with a large stereo....

Some people compensate this with keeping the stock alt. pulley on, but if you do that you are losing 1/2 of the h/p you paid for buying the pulleys... so what is the point?

well i run a 4500 watt amp and 2 2000 watts 10's and i have no problem with the alt. i switch all three pullies.

 

[03greygt]

hey everyone is underdrive pulleys a good little mod?....i seen theehttp://www.partshopper.com/shop/Steeda-Underdrive-Pulley-Sets-for-4.6L-m82.htmlse
and they say they add 8-10 hp is that true?......and installation wise is it hard?....and what do you guys think of them?

thanks
ted

I have an 03 automatic gt that ran 9.01 at 77. I ported the plenum, upr cai and stedda underdrive pullies and went to 9.05 at 78 with the slightest wheel spin. And it was also hotter that day. So take this for what its worth. If you have an automatic car I suggest an edge or a pi converter.

 

['03GTinFLA]

And now is the time on Sprockets when my monkey dances while I post this:



TSB #14520
4.6L 4V Pulley Instructions
Some 1996-2001 Mustang owners, for engine performance purposes, are adding a special front drive pulley kit to reduce front accessory drive speeds. When removing and replacing the crank pulley, if the large bolt used to hold the crank pulley undertorqued, the keyway will shear and cause major engine damage. The resulting engine damage is not warrantable. If the crankshaft pulley bolt is removed it should be replaced as it is a torque to yield bolt. The installation of the crankshaft pulley requires that a specific torque operation be adhered to. The crankshaft pulley bolt must be installed using these 4 steps: 1) Torque to 75 lbs/ft 2) Back out one turn 3) torque to 45 lb?ft 4) continue to tighten and additional 90 degrees.

So are those instructions specific to the 4V 96-01 or do they apply for our cars too?

 

[blackfang]

They are fantastic. A proven mod since day one. AND THEY SAVE YOU GAS! WHY ON EARTH DOESNT EVERYONE WHOS NOT FORCED INDUCTION HAVE THESE THINGS.

Sorry it drives me nuts hearing folk who dont have them saying they are bad. Much better than plenum/tb and they improve your gas mileage. They pay for themselves!

They may be good for the 2V, but for the 4V Al papito has seen some motors that have had air pockets in the oil from them. Plus the oil pump gears have been known to go bad from them and our balancers suck and that also contributes to them. I am not saying all 4v's will have this, but there are enough to convince me not to have them.

 

[Bullitt1063]

I have heard that so long as you you Steeda and not some piggyback pulleys you are good.

 

[mustangman9812]

you can always get a bigger alternator lol

 

[jerry S]

bad mod

I represented a guy who had installed BBK underdrive pullies on his (then) new Mach 1. Within 1 year, his oil pump failed and his engine was completely ruined. The car had only 14,000 miles on it at the time. Ford voided his factory warranty and refused to repair under the warranty not because the parts were installed (which would have violated the Magnuson Moss warranty act) but because they claim that the pullies had been incorrectly installed. There is no way to prove otherwise and the guy is screwed. If your car is still under factory warranty, do not do it unless you want Ford to void your warranty. If your car is out of the warranty period, go ahead just make sure the parts are correctly installed.