That doesn't sound good.
Hopefully this underdrive pullys....
Thread Starter
Safety Car
Joined: Jul 2008
Posts: 3,966
Likes: 4
From: Made In America
St. Jude Donor '10-'11
Hopefully this underdrive pullys....
are what I am looking for. I ordered them from TPIS. They claim 11 rear wheel hp AND only slows the alternator down 2%. How much crank horsepower will they add?
http://www.tpis.com/index.php?module...ry=Pulley+Sets
http://www.tpis.com/index.php?module...ry=Pulley+Sets
Team Owner
Joined: Feb 2006
Posts: 23,144
Likes: 117
From: San Antonio Texas
I put a JBA full pulley set on my Mustang and it was one mod I could feel in the seat of my pants right away! BUT... The Mustang was also spinning the water pump off the pulleys and an LTx motor is not, so you can discount any gains there. Also the reduction I had in the alternator was a bit too much (don't remember the % reduction) and my headlights would go dim below 1500rpm , so I had to go back to a smaller alt pulley to speed it up a little more. Still, the smaller crank pulley was a power maker. There is always a trade off somewhere so be careful how much reduction you go for.
Thread Starter
Safety Car
Joined: Jul 2008
Posts: 3,966
Likes: 4
From: Made In America
St. Jude Donor '10-'11
Drifting
Joined: May 2006
Posts: 1,428
Likes: 7
From: Chewelah Wa
I have the March 2 pulley set....the alternator one is sized to make up for the change in pulley speed. So it basically slows down the water pump and power steering. I have a feeling these are the same as the TPIS ones. I have no problems with them on my L98, as for the increase in power, I am unsure. But every little bit helps. My guess is 5 HP.
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
I have a set of March pulleys (3) that really make a difference.
Engine spools up faster, out-of-the-hole performance is better.
Yet the alt speed is too low so the volts drop below what the alt can hold up around 1400 RPM. Not good for driving in traffic.
Especially at night!
I have tried using different combination's to keep alt/performance compromised. Not much to report as of this date.
Engine spools up faster, out-of-the-hole performance is better.
Yet the alt speed is too low so the volts drop below what the alt can hold up around 1400 RPM. Not good for driving in traffic.
Especially at night!
I have tried using different combination's to keep alt/performance compromised. Not much to report as of this date.
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
The set that TPIS sells is the march 3 pulley amp set. On mine I saw no difference in alternator drop (very small alt. pulley, large w.pump pulley and small crank)....not sure if it's exactly worth 10hp at the tire though.....
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Pro
Joined: Jun 2007
Posts: 626
Likes: 2
From: Coquitlam British Columbia
I have the same results on my 1990. The smaller than stock alternator pulley does the trick without overreving the speed of the alternator. You have to use a 90-1/2" belt.
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
It would be more helpful if we posted our pulley diameters.
Comparing brands is not helping the OP nor us.
As soon as I'm able my diameters will be included here.
Comparing brands is not helping the OP nor us.
As soon as I'm able my diameters will be included here.
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
I put a JBA full pulley set on my Mustang and it was one mod I could feel in the seat of my pants right away! BUT... The Mustang was also spinning the water pump off the pulleys and an LTx motor is not, so you can discount any gains there. Also the reduction I had in the alternator was a bit too much (don't remember the % reduction) and my headlights would go dim below 1500rpm , so I had to go back to a smaller alt pulley to speed it up a little more. Still, the smaller crank pulley was a power maker. There is always a trade off somewhere so be careful how much reduction you go for.
Had same problem with my 98 z28.The lights would go dim at stoplights & alternator would go to under 12 volts according to idiot gauge(alternator).Man this forum is addictive.I now realize after being on this forum for awhile that there is some talented people & people with experiance to said problems giving answers,this is nice & informative.Were I am people come to me for answers.Its nice to ask people questions too(I'm human & learning all the time) when not sure about something & its free!
My advice invest in something else for performance(long-tube headers,roller rockers,etc).People here say long tubes make a difference you can feel!Plus you car will sound badass!
Last edited by 94vettelover2; Oct 29, 2009 at 08:54 PM.
