Underdrive Pulley
Drifting
Joined: Apr 2002
Posts: 1,451
Likes: 0
From: Owensboro Ky
Re: Underdrive Pulley (Glasman66)
I had them on my truck, the complete 2 piece March pulley set. I don't know if it made much difference in power but I seemed to have gotten better gas mileage. The only problem was that at idle you could watch the volt gauge drop. And sor some reason I went through more batteries, must have been hard onthe charging system. But to answer your question, I won't be putting them on my Vette. :seeya
Team Owner
Joined: Jun 2000
Posts: 22,379
Likes: 94
From: Damn taxes! Pimpin' Ain't Easy in Massachusetts
2018 C4 of Year Finalist
St. Jude Donor '03-'04-'08-'09
Re: Underdrive Pulley (yoslambo1@cs.com)
i have them...not sure if they help? :confused:
I felt no difference with the 2 pulley's and an Air pump eliminator kit. The dyno didn't show anything to get excited about either. :rolleyes:
Team Owner
Joined: Jun 2000
Posts: 22,379
Likes: 94
From: Damn taxes! Pimpin' Ain't Easy in Massachusetts
2018 C4 of Year Finalist
St. Jude Donor '03-'04-'08-'09
Re: Underdrive Pulley (scorp508)
The dyno didn't show anything to get excited about either. :rolleyes:
Hey hey hey..... that baby had no fuel before!!!!
Hey hey hey..... that baby had no fuel before!!!!
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Drifting
Joined: May 2002
Posts: 1,509
Likes: 3
From: Hazel Park MI
Re: Underdrive Pulley (Glasman66)
The pulleys and MSD ignition seem to help some and not others. In July I installed the 2 piece (alt and crank) March pulley system from TPIS on my '85 4+3. It now pulls strong all the way through 4700 RPMs, and is a tad bit more responsive at launch. It has given me more power at upper RPMs (4700 RPMs is not considered high RPMs to most, but it is to my vette). And I installed an MSD ignition earlier in the month, and I noticed better throttle response and more ***** in the upper power band range with that. So for me to feel a noticeable difference with the pulleys installed after the MSD ignition, I say the pulleys helped me, and I have NO voltage problems at idle or otherwise. I say do it!! :yesnod: :seeya
Racer
Joined: Apr 2002
Posts: 415
Likes: 0
From: loughborough Leics ENGLAND
Re: Underdrive Pulley (jmrl98)
I have been thinking about fitting some to my 90, but there is so much confusion i keep bottling out at the last minute.
Vic 89 has said many times that it worked for him and his car moves, so i say they must do something :confused: :confused: :confused: maybe its how much do they do :bs
I think i am going to go for it and carry out some before and after tests ( at the track ) that i will post so we can all get to the bottom of it.
Has no one done this before ???
It will be a few weeks before i can do it because i live in England so shipping takes a long time.
I will buy the ASP three piece set
:cheers: Mark
Vic 89 has said many times that it worked for him and his car moves, so i say they must do something :confused: :confused: :confused: maybe its how much do they do :bs
I think i am going to go for it and carry out some before and after tests ( at the track ) that i will post so we can all get to the bottom of it.
Has no one done this before ???
It will be a few weeks before i can do it because i live in England so shipping takes a long time.
I will buy the ASP three piece set
:cheers: Mark
Burning Brakes
Joined: Nov 2000
Posts: 855
Likes: 0
Re: (scorp508)
I only have the crank underdrive pulley on. I have had no loss in cooling or charging at idle.
I believe I might have one on my car. I thought my belt tensioner was wore out because it is out of the service range. I have replaced the belt and compared it with the old one and they were the same size. I'm wondering if I just need a shorter belt. Yesterday with the A/C on at red light I noticed my volts would drop down to about 12.0-12.3 volts, but go back up to about 13.0-13.4 at speed. I shut off the A/C and volts went to 12.8-13.0 @ idle. Oh the alt and battery are two days old.
Safety Car
Joined: Sep 2001
Posts: 4,095
Likes: 1
From: modland CT
Re: (Rick86)
I believe I might have one on my car. I thought my belt tensioner was wore out because it is out of the service range. I have replaced the belt and compared it with the old one and they were the same size. I'm wondering if I just need a shorter belt. Yesterday with the A/C on at red light I noticed my volts would drop down to about 12.0-12.3 volts, but go back up to about 13.0-13.4 at speed. I shut off the A/C and volts went to 12.8-13.0 @ idle. Oh the alt and battery are two days old.
Safety Car
Joined: Sep 2001
Posts: 4,095
Likes: 1
From: modland CT
Re: (scorp508)
Scorp, do you by chance know the diameter of the underdrive pulley?
Much smaller. :jester I honestly don't know. If I were to guess I would say about 7-8".
Much smaller. :jester I honestly don't know. If I were to guess I would say about 7-8".
Racer
Joined: Jul 2002
Posts: 447
Likes: 0
From: Malta Europe
Re: (Rick86)
I did them on my 88 and all that thay give is charging problems when I was leaving at idle the battery will go flat and not start, I had to jump start it with other cars :mad and you have to look at my face when I am somewhere and I go in my vette and clik clik no power !!! so I got pretty :mad and I took them off and had no problems ever since :yesnod: so my opinion says :nono: I sold mine to another vette owner ,even I warned him
what problems they was cousing but hey he wanted them :rolleyes:
what problems they was cousing but hey he wanted them :rolleyes:
Melting Slicks
Joined: Oct 2000
Posts: 2,627
Likes: 8
From: Drag racing junkie Va.
Re: Underdrive Pulley (Lone Ranger)
ATI has a small diameter balancer available($!). Since the pulley is part of the balancer this is the only solution for an LT1.
Sorry for the bad news, Dave :(
[Modified by new92racer, 10:56 PM 8/28/2002]
Sorry for the bad news, Dave :(
[Modified by new92racer, 10:56 PM 8/28/2002]
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
Re: Underdrive Pulley (Glasman66)
You are not going to get the same effect as a L98 will, since the water pump is driven off of the timing gear set. I would think that if you are trying to reduce drag on the engine, an electric water pump would be a better investment on the LT1.