Hey. I have a 94 5.0 f150. I want the extra horses that an underdrive will give me. An underdrive pulley system is just that you don't have to turn other stuff as fast (alternator, pumps, etc...) but I have a 12 in subwoofer hooked to a 760watt amp. Will it be to hard on my alternator or anything if I get them? I wanna know all the cons of underdrive pulleys. Also how much horsepower should I expect? Ive read it can be 4-7 but Ive also read it can be 14-20 more. It's just an XL model so I don't have power windows or cruise control or anything like that steeling power, besides that sub. So whats the catch to underdrive pulleys?

 

I have Motorsport under-drive pulleys on my 92 f-150. Although, I have converted to a 3g 130 amp alternator. Your year truck should all ready have one installed. In my opinion you should have no issues based on my experience.

I have two 10 inch Sony subs, two Kenwood Amplifiers with built in fans, "one class D hooked to subs and one class AB hooked to four 4-way pioneer door speakers, and four Power Acoustic tweeters, "which I don't recommend." I also have a Ford Thunderbird Electric can installed as another power drain source. 0 gauge wire from battery to distribution block. 4 gauge wire to Amps. I still need to upgrade my alternator and ground wiring to o gauge, "currently running at 4 gauge." When bumping deep bass, the gauge moves considerably back and fourth. I rarely do that any more because my ears ring if I listen for to long...

Any way, to answer your question. "Yes the pulleys help a little on your performance."

Although, you get less water flow. Keep an eye on temperature when you idol your vehicle it may get hot, rev your engine up to about 1000 RPM that usually takes care of the problem and allows the thermostat to kick in for me at least.

At night time, while sitting a red light in the drive position, with my heater on full blast, "my lights will dim." The volt meter on my gauge cluster reads right below the N on normal. Once I get going it jumps up to R and my lights return to normal. This happens when I creep down my rocky driveway at about 5-10 mph with no foot on the accelerator.

When I slung a drive shaft about 10 years ago I hacked the exhaust off after the Cat...I noticed an increase in my temperature. Soon as I replaced the muffler which I have dumped right after the cab, damaged cat, and added some piping my vehicles temperature dropped considerably... Although, I lost some performance when adding a Flowmaster muffler compared to my straight pipe I ran for a few months.

Best bolt on performance upgrade would be the pulleys, headers. Other then that 4.10 gears rocked, "but I swapped back to 3.55's do to highway driving."

 

Thank you so much. That's really helpful, though I'm a bit worried about the pump cuz I already have a very minor leek when it's very cold from my radiator hoses. Do you mind me asking where and how much you got your pulleys for?

 

They put less strain on the pump. I can't remember, "It's been years.

I'm using the stock 3G alternator pulley in place of the Ford Racing alternator pulley. The pulley is the same size and half the weight. The thickness of the Ford Racing pulley were it slides on the alternator shaft was to great and I could not tighten the nut down enough. Although, on the factory 2G alternator I had no issues.

 

I have some March performance under drives on my 88 302 and I left the stock alternator pulley on to lessen the charging issues. I still have the stock 2g alternator. I get some pretty voltage drop while idling at stoplights at night with lights and heater running, even worse when if the wipers have to be on. I am currently getting ready to install a 150 amp 3g alternator with 1/0 charging cables so hopefully this resolves the issues.


As for the good, I can't tell you the exact power numbers but I have noticed slightly less down shifting on the highway and a little bit better fuel mileage since adding the pulleys.

 

you'd be better off setting up electric fans. it can be done for next to nothing with JY parts.


or....you could do both.

 

This link below is the setup I did for electric fans...

https://www.ford-trucks.com/forums/1...c-fan-mod.html

 

I recently installed a set of March underdrive (Power & Amp Series) pulleys on my 93 f150 5.0l auto, I also have an amp and sub. These pulleys are recommended for automatic vehicles. I haven't had any charging issues.

The part number for these is 1015-08, check them out here FORD 429-460 C.I. V-BELT PULLEY SETS