underdrive pulleys do they work???
Thread Starter
Instructor
Joined: Aug 2000
Posts: 116
Likes: 0
From: philadelphia,pa pa
underdrive pulleys do they work???
I see march has an underdrive pulley set for lt 1 and I was wondering if it even works for the lt1 heres why. I understand the concept of underdrive pulleys and I dont see where its a benifit for lt1's.First of all the water pump is driven off of the cam gear so the water pump is out of the picture all together.The a/c (if it is off )is just a free wheeling pulley so that is out of the picture. Next is the power stearing pump. Now I am not sure on this one but I thought it was only taking power to run power stearing when you are turning.Last is the alternator which definetly takes power to turn, but the march kit gives you a new pulley for the alt. to compensate for the underdrive crank therefore canceling out the benifit of the underdrive.Am I right in my thinking? has anyone tried these?are they worth it? thanks for your input. Rich
Team Owner
Joined: Nov 1999
Posts: 32,782
Likes: 11
From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
Cruise-In VI Veteran
Cruise-In VII Veteran
Never liked these, a fully charged battery is more important.
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
only useful on high rpm engines when you have a problem liquidating alternators. most the time you can just up the size of your alt pully and accomplish what you need to. L98s for example will roast alternators fairly quickly if you spin 6500rpm or more and have a stock size pully.
Melting Slicks
Joined: Jul 2003
Posts: 2,284
Likes: 4
From: Canton MI
only useful on high rpm engines when you have a problem liquidating alternators. most the time you can just up the size of your alt pully and accomplish what you need to. L98s for example will roast alternators fairly quickly if you spin 6500rpm or more and have a stock size pully.
Safety Car
Joined: May 2004
Posts: 4,469
Likes: 275
From: Naples FL
The real question is why do you think you need these underdrive pulleys. There's very little gain and you risk a dead battery. I only see a downside here.
March is about a half mile from my house and I've found that they aren't very helpful. I asked them for a pulley set for my track car. I don't have an air pump and no a/c. They tried to sell me a stock set of pulleys and had no interest in helping me.
That made my decision real easy.
Richard Newton
101 Projects for Your Corvette 1984-1996
Autocross Performance Handbook
March is about a half mile from my house and I've found that they aren't very helpful. I asked them for a pulley set for my track car. I don't have an air pump and no a/c. They tried to sell me a stock set of pulleys and had no interest in helping me.
That made my decision real easy.
Richard Newton
101 Projects for Your Corvette 1984-1996
Autocross Performance Handbook
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
I see march has an underdrive pulley set for lt 1 and I was wondering if it even works for the lt1 heres why. I understand the concept of underdrive pulleys and I dont see where its a benifit for lt1's.First of all the water pump is driven off of the cam gear so the water pump is out of the picture all together.The a/c (if it is off )is just a free wheeling pulley so that is out of the picture. Next is the power stearing pump. Now I am not sure on this one but I thought it was only taking power to run power stearing when you are turning.Last is the alternator which definetly takes power to turn, but the march kit gives you a new pulley for the alt. to compensate for the underdrive crank therefore canceling out the benifit of the underdrive.Am I right in my thinking? has anyone tried these?are they worth it? thanks for your input. Rich
Last edited by BADDUCK; Mar 24, 2008 at 09:52 AM.
Drifting
Joined: Oct 2006
Posts: 1,934
Likes: 3
From: Citrus Heights California
You can get the March Power and Amp type under drive pullys. I have a set. The alternator pully is a little bigger. It charges fine. I threw away my frisbee. I installed an Edlebrock polished aluminum water pump. I also installed polished aluminum March pullys and a chrome high out put alternator. I just wanted to give it more bling. But I swear the Vette performed better. It's been on about 2 years with no problems.
Last edited by Kool88vette; Mar 24, 2008 at 10:22 AM.
Team Owner
Joined: Feb 2006
Posts: 23,218
Likes: 117
From: San Antonio Texas
I think you're right about not being much benefit on an LT1. I had a full set on my GT Mustang and I really could feel the difference, but the belt ran everything on that engine. I could barely drive it at nite becuse the lights would go so dim at a stop. I had to switch back to the stock Alt. pulley to speed it up, but then had problems with the tensioner not working right. It was hardly worth the hassle, and would probably a waste of time and money on an LT1.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
only useful on high rpm engines when you have a problem liquidating alternators. most the time you can just up the size of your alt pully and accomplish what you need to. L98s for example will roast alternators fairly quickly if you spin 6500rpm or more and have a stock size pully.
