Underdrive pulley opinions please!
04-13-2004, 12:43 AM
#1
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Underdrive pulley opinions please!
Ok today the "MR.GASKET" under drive pulleys i ordered showed up.Well upon inspection it was clear that these were some very nice peices if i do say so myself.And extremely different in the way of size.The old crank pulley fit around the new one.
Well after i installed them i fired it up to check for any problems and whatever with none found.
Now my question here is one this kit came with a paper claiming that on a dyno and a stock 5.0 they seen 18+ horse power.Now im one of these guys that belives none of what i hear and half of what i see so this is a bit hard to swallow.I couldnt run her tonight since its like 35 degrees out and too cold for me.But i could tell a difference in the revs.It definately revs quicker Than before but im having a hard time believing 18 hp.
What do you guys say?Anyone ever actually dynoed one with and without pullies?Or have any facts that would support these claims?
Also a word of advice to all who buy these "DO NOT USE THE ALTERNATOR PULLEY" its doing you no justice.My alternators power with it on without reving the car up was 12.50 after you rev it up it went to 14.56 volts.I yanked it off and to be honest cant see any difference with it running the old one other than the charging is better but not great.This may not be an issue for those of you with EFI that idle closer to 1,000 rpm but mine idles at 450 rpm and at that rpm i wasnt charging.But when i tested it it seemed to start charging at around 1,000 rpm so you may get by.Trial and error is what i suggest.
Other than that they seem to help out but im still not sure abouyt the claims.Opinions please?
Well after i installed them i fired it up to check for any problems and whatever with none found.
Now my question here is one this kit came with a paper claiming that on a dyno and a stock 5.0 they seen 18+ horse power.Now im one of these guys that belives none of what i hear and half of what i see so this is a bit hard to swallow.I couldnt run her tonight since its like 35 degrees out and too cold for me.But i could tell a difference in the revs.It definately revs quicker Than before but im having a hard time believing 18 hp.
What do you guys say?Anyone ever actually dynoed one with and without pullies?Or have any facts that would support these claims?
Also a word of advice to all who buy these "DO NOT USE THE ALTERNATOR PULLEY" its doing you no justice.My alternators power with it on without reving the car up was 12.50 after you rev it up it went to 14.56 volts.I yanked it off and to be honest cant see any difference with it running the old one other than the charging is better but not great.This may not be an issue for those of you with EFI that idle closer to 1,000 rpm but mine idles at 450 rpm and at that rpm i wasnt charging.But when i tested it it seemed to start charging at around 1,000 rpm so you may get by.Trial and error is what i suggest.
Other than that they seem to help out but im still not sure abouyt the claims.Opinions please?
04-13-2004, 12:55 AM
#2
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RE: Underdrive pulley opinions please!
Hey GM killer .. well i bought some pulleys about a month ago and it did rev faster almost felt like i lost a little tourqe but wasnt sure. Then after a few good hard runs i felt a little gain but wasnt like neck snapping ,but i did notice! Im going to Dyno this weekend but i did more mods other then just pulleys so i wouldnt be able to give you facts on how much HP they gave me. But i have heard people getting up to 15 HP freed up.
04-13-2004, 02:08 AM
#4
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RE: Underdrive pulley opinions please!
I should have grabbed a pic but these pullies (THE NEW ONES) were tiny compared to the old ones.
Were the ones you guys bought very small as well.
To be honest i wasnt a fan of these until i put some on a friends and it made a difference.I figured if they did a descent job on his and they dont cost much ill throw them on the stang and see what if anything i gain.
But i could tell a difference on his 4.6.But 4.6's and 5.0's are like day and night.So i dont know.
Were the ones you guys bought very small as well.
To be honest i wasnt a fan of these until i put some on a friends and it made a difference.I figured if they did a descent job on his and they dont cost much ill throw them on the stang and see what if anything i gain.
But i could tell a difference on his 4.6.But 4.6's and 5.0's are like day and night.So i dont know.
04-13-2004, 01:49 PM
#5
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RE: Underdrive pulley opinions please!
Killer, Killer, Killer, what a skeptic you are!
Underdrive pulleys do increase the HP to the rear wheels by at least 15 HP at WOT, much data proves this. They also protect the accessories life by driving them slower, especially the alternator. Unless you spend a lot of time idling around, I would install the alternator pulley back on to get the maximum benefit from the pulleys. By making the crank pulley as small as the original water pump pulley and the water pump pulley much bigger, this not only slows down the water pump, but it also slows down everything else driven off the crank including the power steering pump and AC when it is in use. The water pump is the biggest power drain, as the power required to pump water around goes up with the square of the speed, so at 4,000 rpm, it takes 4 times as much power to run the pump than it does at 2,000 rpm.
When I installed a set on my Stang back in 1994, the ET's dropped from an average of 15.60's to 15.30's with no other change being made and the weather was about the same both days. Unless you spend way too much time idling around with the AC on, I would put the bigger pulley back on the alternator and maximize the benefits you get from the pulleys. Like you said, it starts charging fine after about 1,000 rpm, so why worry!
Underdrive pulleys do increase the HP to the rear wheels by at least 15 HP at WOT, much data proves this. They also protect the accessories life by driving them slower, especially the alternator. Unless you spend a lot of time idling around, I would install the alternator pulley back on to get the maximum benefit from the pulleys. By making the crank pulley as small as the original water pump pulley and the water pump pulley much bigger, this not only slows down the water pump, but it also slows down everything else driven off the crank including the power steering pump and AC when it is in use. The water pump is the biggest power drain, as the power required to pump water around goes up with the square of the speed, so at 4,000 rpm, it takes 4 times as much power to run the pump than it does at 2,000 rpm.When I installed a set on my Stang back in 1994, the ET's dropped from an average of 15.60's to 15.30's with no other change being made and the weather was about the same both days. Unless you spend way too much time idling around with the AC on, I would put the bigger pulley back on the alternator and maximize the benefits you get from the pulleys. Like you said, it starts charging fine after about 1,000 rpm, so why worry!
04-13-2004, 03:47 PM
#7
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RE: Underdrive pulley opinions please!
for some reason when i bought my car it had pullies but was missing the alternator pully. the only prob i had was at idle with the air on it blows out slower then when you are driving it is fine. but other than that it is good.
04-13-2004, 06:41 PM
#10
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RE: Underdrive pulley opinions please!
Why don't you guys trust anyone but march? A pulley is a pulley... As long as its the same size its still going to charge, or not charge, the same amount. I had a friend that borrowed my BBK pulleys and made his out of aluminum at his shop. Same size, just lighter.