Underdrive pulleys and electric fans

I see there are clames that underdrive pulleys will gain about 10-15 horsepower, anyone have them and have any thoughts on how it felt after. Also i know an electric fan will decrease drag and i have an electric fan from a 5.0 mustang. I wanted to do both and a few other small things all at once to see how it works out

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It would be really interesting to see before and after with dyno results. There is no free lunch. So I think you need to be careful that you take into account that the alternator will be putting out a lower amount of electricity and the fan will be taking more. If I was drag racing or doing short rips I would figure out how to put a switch on the alternator so it cuts out for that short time I was racing.

alwaysFlOoReD said:

It would be really interesting to see before and after with dyno results. There is no free lunch. So I think you need to be careful that you take into account that the alternator will be putting out a lower amount of electricity and the fan will be taking more. If I was drag racing or doing short rips I would figure out how to put a switch on the alternator so it cuts out for that short time I was racing.

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Second battery may help out, im in need of a two battery system regaurdless of what i do and possibly a new alternator soon. A/C pump has a crack in it and i don't plan on fixing it so i might as well delete that for the time being while im at it.

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I did my efan and underdrive pulleys at the same time a few years ago on my original engine. It felt better for sure vs the stock setup, and I got improved fuel economy too.

kevinbmx77 said:

I see there are clames that underdrive pulleys will gain about 10-15 horsepower,

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Claims, claims, claims - never seen a dyno test.

As alwaysFlOoReD said, there's no free lunch, including the cost benefit.

Dyno test would be good but impractical for most people. Maybe track your mpg for about 10 tanks before and after to see if more power for less fuel.

What will more power get you - faster times between red lights?

A proper efan setup is not cheap.

I've been running both for years, did the U/D crank pulley first, then the E-fan. Both improved performance and fuel mileage slightly--about .7mpg each and a small but noticeable improvement in power. E-fan really helps with warm up time--much faster. Definitely worth doing, they are mods that will pay for themselves.

The e-fan also makes the interior much quieter, one does not realize how noisy the stock fan is until it's gone.

E-fan is a good mod, no downside at all, only an upside

Underdrive gaining 10-15HP would be for 5.0l and larger engines, 3.0l wouldn't see anywhere near that.
But as long as you don't spend much time at idle RPMs it won't hurt anything

Rearanger said:

Claims, claims, claims - never seen a dyno test.

As alwaysFlOoReD said, there's no free lunch, including the cost benefit.

Dyno test would be good but impractical for most people. Maybe track your mpg for about 10 tanks before and after to see if more power for less fuel.

What will more power get you - faster times between red lights?

A proper efan setup is not cheap.

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There was a guy on most Ranger forums a few years back named Underdog that produced and sold underdrive kits with dyno test results (among other products). They were something like 7 or 8 hp and 11 or 12 lb-ft at the wheels. Keep in mind, this is not the engine making more power(and using more fuel), it is simply reducing the parasitic drag, which makes more of the power being made by the engine available. Think of it as driving around with the AC compressor suddenly disengaged after having it engaged the whole time. The fuel savings are real. The improved performance is real. The e-fan achieves the exact same thing.

Obviously, you're free to be skeptical since the results were from the seller and not an impartial party, but having bought a set myself it seems plausible to me. He was a good guy to deal with, and offered several things for our trucks that weren't available from the larger aftermarket. Never saw a bad review from a customer and everybody was disappointed to see him close.

RonD said:

E-fan is a good mod, no downside at all, only an upside

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Except maybe your bank account. Quality and reliable install is not cheap.

I think Ford used underdrive pulleys on some Mustang models, although if the factory does it is it underdrive, lol.

Gain is real, there are independent dyno tests for this mod.

But gain is related to original HP, so a %, not a fixed number, looking at the numbers I would say 5% gain at 3,000rpm, so a 5.0l with 200hp at 3,000rpm would see 210hp at 3,000rpm
3.0l that had 130hp at 3,000 would show 136hp at 3,000rpm

You would lose a little if you were to overdrive alternator back to factory idle rpm, but no dimming lights at idle, lol.
And you can see a rise in idle temp, not overheating just running a bit warmer than before when idling because water pump is not spinning as fast.

Rearanger said:

Claims, claims, claims - never seen a dyno test.

As alwaysFlOoReD said, there's no free lunch, including the cost benefit.

Dyno test would be good but impractical for most people. Maybe track your mpg for about 10 tanks before and after to see if more power for less fuel.

What will more power get you - faster times between red lights?

A proper efan setup is not cheap.

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Im making a drift truck, or atleast trying, i already have the axle mounted over leaf, they are f-150 leaves with an add a leaf and an explorer 8.8 with 3.73 and lsd (wanting 4.10s or maybe 4.56). All together it should have little axle wrap by now but id like to get traction bars of a 5.0 explorer. After doing all that it definitely feels alot better and i can get it to start sliding but it needs just alittle more power. I know its a truck and not meant for it but i like doing stuff different than everyone else.
And for the electric fan setup i have a fan from a 95 mustang gt that i plan on using for a 5.0 swap but that wont be for a long time since i sold the engine i was going to be using. Decided i didnt want it carburated or bored 60 over.

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I put an e-fan on my '00 and when driving on city streets with the AC and e-fan both running, because my engine engine isn't spinning very fast my stock alternator barely keeps my battery charged. An under drive pulley will slow the alternator down reducing it's charging rate, so I'm not so sure it's a good idea to put an under drive pulley on an AC equipped Ranger that has an e-fan.

Rearanger said:

Except maybe your bank account. Quality and reliable install is not cheap.

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that is almost..mmmmm naaa actually......that is more patently ridiculous then your first statement.

McCormack said:

I put an e-fan on my '00 and when driving on city streets with the AC and e-fan both running, because my engine engine isn't spinning very fast my stock alternator barely keeps my battery charged. An under drive pulley will slow the alternator down reducing it's charging rate, so I'm not so sure it's a good idea to put an under drive pulley on an AC equipped Ranger that has an e-fan.

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did you install an alternator from a 1950 ford on your truck? because if yours is working correctly a stock fan and ac system cant hurt it unless you have a giant sound system your leaving out of the mix, or a 10000 watt light or something...

bobbywalter said:

did you install an alternator from a 1950 ford on your truck? because if yours is working correctly a stock fan and ac system cant hurt it unless you have a giant sound system your leaving out of the mix, or a 10000 watt light or something...

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Is that your opinion, or do you have an e-fan installed on your truck and you're speaking from actual real-world experience.

no....not an opinion.



not even close to an opinion....if it was a guess or opinion i would have had little doubt left to imply it was more then a guess built into the statement.. or at least attempted to.

your alternator is either fawked up or it has the wrong one installed. or the fan is fawked up and drawing 70 amps or something.


last sytem i checked in a 4.0 truck with everything on...high beams, blower motor ect was drawing 50 plus amps. so 80 plus with a huge e fan.....well within the capacity of a stock ranger alternator. they can make 90 amps at idle....there is some variance....but 95 amp is stock....upgrading to a 130 is cake.


pretty much everything 1/2 ton and down has an electric fan now....specifically due to efficiency.


and i went to efans only around 97 after dismal performance for a few years from mechanical cooling in my v8 ranger and most v8 conversions to that point i did. depending on use, the electric fan really shines... for some it wont matter at all....for others it is a worthy investment. just depends on how its used. ones actual drive cycle will prove out any gains, but theres no loss when installed correctly to say the least...

since 2008, my personal truck contains over 6 liters of diesel power with a smaller alternator then yours and biggest e fan ford makes cooling it for hundreds of thousands of miles.

so.


not realy an opinion.