are under drive pulleys worth it ?
Originally Posted by Lithium
If search is working use it...so much great info out there about this 
Trending Topics
Its not really worth it if you have an auto because you have to put an alternator overdrive pulley on and I would think that would significantly decrease the HP increase you might see
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Addict
Joined: Jan 2004
Posts: 2,042
Likes: 0
From: Grosse Pointe Woods, MI
Originally Posted by Luna
Its not really worth it if you have an auto because you have to put an alternator overdrive pulley on and I would think that would significantly decrease the HP increase you might see
Originally Posted by Luna
Its not really worth it if you have an auto because you have to put an alternator overdrive pulley on and I would think that would significantly decrease the HP increase you might see
Even with the alternator overdrive, have you ever actually spun over the alternator pulley? You can almost look at it and make it move if you stare hard enough!
I've never heard of an OD alternator pulley being needed with an auto. It's like what i said in the other thread, our cars are designed to put out enough juice at IDLE to run the car forever. As long as you aren't using more than 75% of the output to run the car, you SHOULD be able to idle forever with even an underdrive pulley. Once you start moving around, you have plenty of juice.
Originally Posted by orangeapeel
March makes a good one too for half the price.
Originally Posted by TheBlurLS1
As long as you aren't using more than 75% of the output to run the car, you SHOULD be able to idle forever with even an underdrive pulley.
Originally Posted by TheBlurLS1
Explain-e-ate this one to me!
Even with the alternator overdrive, have you ever actually spun over the alternator pulley? You can almost look at it and make it move if you stare hard enough!
I've never heard of an OD alternator pulley being needed with an auto. It's like what i said in the other thread, our cars are designed to put out enough juice at IDLE to run the car forever. As long as you aren't using more than 75% of the output to run the car, you SHOULD be able to idle forever with even an underdrive pulley. Once you start moving around, you have plenty of juice.
Even with the alternator overdrive, have you ever actually spun over the alternator pulley? You can almost look at it and make it move if you stare hard enough!
I've never heard of an OD alternator pulley being needed with an auto. It's like what i said in the other thread, our cars are designed to put out enough juice at IDLE to run the car forever. As long as you aren't using more than 75% of the output to run the car, you SHOULD be able to idle forever with even an underdrive pulley. Once you start moving around, you have plenty of juice.
"Stock Alternator Pulley - Most commonly used. Suitable for most applications.
Overdrive Alternator Pulley - Recommended for automatic cars to help bring alternator speeds back to near stock levels without sacrificing too much horsepower. Extremely important for vehicles with high accessory drag such as cars with lots of stereo modifications.
Underdrive Alternator Pulley - Recommended mainly for track use. Not recommended for daily street use due to low alternator charging."
Thats straight from Thunder Racing
Here's a negative statement: I have a 25% underdrive pulley on a 6 speed. If the rpm is lower than 1,800 and you're driving through a parking around a curve, the power steering is dead. You have to push in the clutch and blip the throttle. If you have an A4 car you won't be able to clutch/gas. 
You can feel some horsepower added for sure, but the poor power steering is the most obvious PITA.
You can feel some horsepower added for sure, but the poor power steering is the most obvious PITA.
i must be wigged out because i got the slp 25% underdrive and was told not to touch my altenator or belt tensioner. i can feel any difference on take off or in a race (obviously) but i can feel a difference when i fall out to pass someone and punch it (from about 50mph).
im deffinately sold on it and if i bought another fbody tomorrow, i'd buy a pulley for it also.
and i have an A4
im deffinately sold on it and if i bought another fbody tomorrow, i'd buy a pulley for it also.
and i have an A4
Originally Posted by 99camarosupersport
i've heard some bad things from users on the board about the march UD pulleys. can't think of what the comments were off the top of my head.
Originally Posted by RICEETER
i must be wigged out because i got the slp 25% underdrive and was told not to touch my altenator or belt tensioner. i can feel any difference on take off or in a race (obviously) but i can feel a difference when i fall out to pass someone and punch it (from about 50mph).
im deffinately sold on it and if i bought another fbody tomorrow, i'd buy a pulley for it also.
and i have an A4
im deffinately sold on it and if i bought another fbody tomorrow, i'd buy a pulley for it also.
and i have an A4
Do you lose power steering as Firehawk mentioned; in an A4?
I have a 25% underdrive pulley on a 6 speed. If the rpm is lower than 1,800 and you're driving through a parking around a curve, the power steering is dead. You have to push in the clutch and blip the throttle. If you have an A4 car you won't be able to clutch/gas.