Underdrive pulleys worth it??

I've been researching pulleys for my 5.0. and came across
this article. An actual DYNO test! Dunno how impartial
the testers are as they are from a Ford magazine but its
better than nothing.

"Testing underdrlve pulleys might sound trivial, but it's one of those subjects that generates the most questions for us. Do they really make power? Will I have charging problems? As we've said many times before - yes, underdrive pulleys make power. How much? More on a stock car such as the one featured here, but you'll see an improvement even if your car has heads/cam/intake or other such goodies. Take a look and compare the numbers.This 153,000-mile 5.0 picked up solid horsepower and torque all the way from start to finish on the dyno. Fifteen horsepower for less than 100 bucks"

link: http://www.marchperf.com/superford1.html

I knew I wasn't crazy! I had them on my stock 86GT and noticed a difference, then took them off to sell the car, then put them back on and noticed a good gain.

Still not worth it for a DD though, charging issues (esp at night sucks)

i got a set of UD pullies for 40$
ebay is my friend

i love ebay parts

fox_bodies_rule said:

WOW! real dyno data. Thanks for shedding some light on the subject Daggar I wnet to the site and those guys are serious! I have to also go back to my original comment re. dollar/hp and sign up with DTT92LX's comment about the $25/HP ratio. A set of 185 AFR heads filled with the parts, AFR catolog price $1,375. Assume all is there to support the heads and figure about a 60 hp gain, guess what? $23/hp and some change, not including gaskets and other assorted crap, so round up to $25 dollars! Science and math, what a concept.

Click to expand...

I know this is an old thread but I didn't bring it back up. But since it's here I'd like to add a little input.

The dyno test that was done didn't really tell the whole truth. The fact is you have to actually put the pulley on to test it. They just removed the belt. This is significant because an aluminum pulley is generally much lighter than a steel pulley and that in itself will reduce rotating mass freeing up HP. When you do all 3 pulleys you are removing a bunch of weight. Additionally, many front wheel drive engines don't drive the water pump from the serpentine belt, they're driven off of the timing chain/belt.

There are many, many reports out there that lay claim to a 5 HP increase from just a underdrive crank pulley. Now imagine if you change all 3 pulleys.

Also anybody who would pay $150 for a set of pulleys should have their head examined. Here's a set that are identical to mine that I put on mine a couple of years ago.

http://cgi.ebay.com/ebaymotors/86-9...ewItemQQcategoryZ38656QQitemZ8040321579QQrdZ1

UNDERDRIVE PULLIES ARE WORTH THE MONEY, BUT DON'T BUY THE ALUMINUMS. THE STEELS WORK JUST AS GOOD AND THEY ARE CHEAPER. AS FOR THE CHARGING QUESTION, MY CAR DOES THE SAME THING W/THE AMP GAUGE BUT I CHECKED THE VOLTAGE W/EVERYTHING ON AND I AM STILL GETTING 14.2V. YOU CAN ALSO GET A BRAND NEW ALTERNATOR @ OREILLY'S FOR $130 (MASTER PRO PLATINUM SERIES).

i dont have any problem with pullies no idle problems but my A/C takes a moment longer to work but it not a problem

What is a good alternator choice?

What is a good alternator choice for a under driven pulley setup? My current alternator is only producing 55 Amps at 2000 RPM. Doing the math I need about 90+ Amps to add electric fuel pump and stereo. I am thinking about moving my battery to the trunk, and adding a second battery in parallel. I am also thinking about adding a solar panel, adding a better voltage regulation setup also came to mind.

Any thought ideas or suggestions?

enyawix said:

What is a good alternator choice for a under driven pulley setup? My current alternator is only producing 55 Amps at 2000 RPM. Doing the math I need about 90+ Amps to add electric fuel pump and stereo. I am thinking about moving my battery to the trunk, and adding a second battery in parallel. I am also thinking about adding a solar panel, adding a better voltage regulation setup also came to mind.

Any thought ideas or suggestions?

Click to expand...

I would figure at least a 160 Amp one from someone like FFI.
http://fordfuelinjection.com/index.php?p=70

Coupled along with a good wiring and a 1 7/8 pulley from here.
http://fordfuelinjection.com/index.php?p=67

How big is your stereo?

If the 130/160 is not enough then you could convert it pretty easily for $75 with a 3G 200 Amp rectifier from here.
http://fordfuelinjection.com/index.php?p=67

Never heard about a solar panel setup though.

Good Luck.

I have the entire set, crank, water pump and alternator from MARCH. I had them on my car when it was stock and no issues, unless I turned up the BASS! other than that everything was fine. I also USed my stock belt still and it worked GREAt for years!! You don't need a new belt!