Underdrive...
11-16-2010, 07:39 PM
#1
Senior Member
Thread Starter
Join Date: Jun 2010
Location: Camden, Alabama
Posts: 605
Likes: 0
Received 0 Likes
on
0 Posts
Underdrive...
Does anyone have any expierience with underdrive pullies? If so, what are the benefits seen/felt? How hard are they to put on? Also, what brand have you had the best success with? (FYI, I have a 90 F150 4x4 5.0L 5psd)
11-16-2010, 08:38 PM
#2
Springer Spaniels Rule
The only thing they do is take some drag off of the crank, what they do is slow down the accessories, you probably wont notice any power, its like anything else with so called power adders, you need more than one to feel any real difference.
11-16-2010, 08:38 PM
#3
Everything that can be done to free up more HP.
Underdrive pulleys are one way to free up horsepower to improve your vehicle's performance. They reduce the power used to turn accessories so that extra power can be used at the transmission.
It may not be much by itself but with a combination of other tricks, it can add up.
I did install under drive pulleys on a 351W 4V HO engine. I don't think I notice the difference.
Underdrive pulleys are one way to free up horsepower to improve your vehicle's performance. They reduce the power used to turn accessories so that extra power can be used at the transmission.
It may not be much by itself but with a combination of other tricks, it can add up.
I did install under drive pulleys on a 351W 4V HO engine. I don't think I notice the difference.
11-17-2010, 12:36 AM
#5
Senior Member
Thread Starter
Join Date: Jun 2010
Location: Camden, Alabama
Posts: 605
Likes: 0
Received 0 Likes
on
0 Posts
I do plan on adding other parts. A new cap n rotor, coil, and spacer this week. Have a high flow air intake, new wires and plugs already on. Will be adding an E fan kit when the ability comes. I need some more power, just not enough for me at the moment lol (probably never will be lol) Just gathering ideas bout how to make my engine better.
11-17-2010, 01:09 AM
#7
Senior Member
Thread Starter
Join Date: Jun 2010
Location: Camden, Alabama
Posts: 605
Likes: 0
Received 0 Likes
on
0 Posts
Already replaced the wires... they are less than 6 months old. As the money comes along, I will keep upgrading the truck. This is why I wanted an older truck.... that way I could work on it myself. At least more than I could with a new vehicle.
Trending Topics
11-17-2010, 08:28 AM
#8
Senior Member
Do you like your A/C down there in Alabama... well underdriving the A/C compressor sure will help NOT...
Undrive pulleys are for race cars not cars and trucks you plan to drive on the street... they just make the accessories work less... so your booming audio system will kill the battery real fast because the alternator just cant keep up.
Undrive pulleys are for race cars not cars and trucks you plan to drive on the street... they just make the accessories work less... so your booming audio system will kill the battery real fast because the alternator just cant keep up.
11-17-2010, 08:57 AM
#9
Senior Member
Join Date: Jan 2010
Posts: 498
Likes: 0
Received 0 Likes
on
0 Posts
I'll be the odd man out here and say they rock!!!!
Ive got them on my truck and instantly noticed it was snappier on the rev.
To contradict what others have said: they dont have to be used for strictly race cars. My truck is one of my daily drivers and they provide no problems at all or interfere with my driving at all.
The only thing I noticed was that the truck heats up a little faster because the water pump is turning slower, but up here in Iowa in the dead of winter thats a nice feature. I do have efans installed and as soon as they kick on there has never been an issue with over heating.
Looking at the alternator keep in mind its turning slower thus putting out less power. I have no extra electronics so this presents no problem at all to me, but if you have subs and an amp or off road lights you may need to put a beefier alternator on.
Between my pulleys and efans I picked up about 3 mpg and thats where I saw the best benefit. Power improved, engine is working less, and MPG's are up so I see no reason not to add this to the list of mods you want to do.
To address your question about a hard install: very very easy. Take off belt, Unbolt old ones, install new ones, put belt on (you will need to get a new belt thats shorter) then your done. Might want to soak the bolts with some wd40 or whatever you use.
DOOOOOOOOOOOOOOOO IT.
Ive got them on my truck and instantly noticed it was snappier on the rev.
To contradict what others have said: they dont have to be used for strictly race cars. My truck is one of my daily drivers and they provide no problems at all or interfere with my driving at all.
The only thing I noticed was that the truck heats up a little faster because the water pump is turning slower, but up here in Iowa in the dead of winter thats a nice feature. I do have efans installed and as soon as they kick on there has never been an issue with over heating.
Looking at the alternator keep in mind its turning slower thus putting out less power. I have no extra electronics so this presents no problem at all to me, but if you have subs and an amp or off road lights you may need to put a beefier alternator on.
Between my pulleys and efans I picked up about 3 mpg and thats where I saw the best benefit. Power improved, engine is working less, and MPG's are up so I see no reason not to add this to the list of mods you want to do.
To address your question about a hard install: very very easy. Take off belt, Unbolt old ones, install new ones, put belt on (you will need to get a new belt thats shorter) then your done. Might want to soak the bolts with some wd40 or whatever you use.
DOOOOOOOOOOOOOOOO IT.
11-17-2010, 10:27 AM
#10
Converted
[quote=SEMPERFIDELUS8403;653618]Does anyone have any expierience with underdrive pullies? If so, what are the benefits seen/felt? How hard are they to put on? Also, what brand have you had the best success with? (FYI, I have a 90 F150 4x4 5.0L 5psd)[/quote
Be careful if your car is driven on the street to not have more than 15-20% underdrive. Some companies also offer stock diameter crankshaft and accessory pulleys. Poorly designed cheap pulleys or copies and knock-offs of major brands can have severe side effects because of too much underdrive of the alternator, power steering, and/or air conditioning units, which are not spinning fast enough. These lead to dips in alternator voltage, power assist, and air conditioning effectiveness may be noticeable, especially at idle. The headlights may dim when coming to a stop, or the stereo may lower in volume, for instance. Too much underdrive for a race car is not much of a concern, but for a daily driven vehicle it can be a major annoyance.
Changing the original crankshaft pulley can have negative effects if the replacement pulley is not manufactured properly. A crankshaft or accessory pulley that is not machined or balanced properly can cause severe damage. For most domestic V8s a harmonic damper is necessary to absorb crankshaft vibrations. Early to mid-year V8's kept the pulley and damper as separate components.
Be careful if your car is driven on the street to not have more than 15-20% underdrive. Some companies also offer stock diameter crankshaft and accessory pulleys. Poorly designed cheap pulleys or copies and knock-offs of major brands can have severe side effects because of too much underdrive of the alternator, power steering, and/or air conditioning units, which are not spinning fast enough. These lead to dips in alternator voltage, power assist, and air conditioning effectiveness may be noticeable, especially at idle. The headlights may dim when coming to a stop, or the stereo may lower in volume, for instance. Too much underdrive for a race car is not much of a concern, but for a daily driven vehicle it can be a major annoyance.
Changing the original crankshaft pulley can have negative effects if the replacement pulley is not manufactured properly. A crankshaft or accessory pulley that is not machined or balanced properly can cause severe damage. For most domestic V8s a harmonic damper is necessary to absorb crankshaft vibrations. Early to mid-year V8's kept the pulley and damper as separate components.
