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UNDERDRIVE PULLEYS

Old 04-15-2007, 09:19 PM
  #21  
odiaz
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Default RE: UNDERDRIVE PULLEYS

The UDPs do slow down your alternator but it only affects it's output at idle. The output curve on an alternator is not linear, it tops out at about 1000-1200 RPM. What that means is that with the new pulleys, you would have top operate at 1250 RPMs to put out the same power as with the stock pulleys. After 1250 RPMs, the output of the alternator is the same with the old or the new pulleys.

The net effect is that unles you plan to operate all of your electrical devices at idle, having a set of UDP poulleys is not going to affect the operation of your electrical system at all. So go ahead and add the UDPs if you think you can benefit from the extra 10 HP. The difference is noticeable immediately.

The installation is not difficult if you ha the right tools. There are a few things to watch out for. Many say that you need to remove the fan showd and fan for better clearance but I've found that its unnecesary if you use a 4" stubby impact wrench. Sears sells them.

I wrote up the entire procedure and posted it here.

http://www.cherod.com/mustang/HowTo/Pulleys.htm
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Old 04-15-2007, 10:44 PM
  #22  
howarmat
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Default RE: UNDERDRIVE PULLEYS

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Old 04-16-2007, 11:00 PM
  #23  
2k05gt
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Default RE: UNDERDRIVE PULLEYS

ORIGINAL: zesty

steeda underdrive pullies really give you about 10 hp?
Pulleys can free up about 10 hp

BrenspeedClaims 10hp
Mustang Monthly claims 11hp

ORIGINAL: 07GTEddy
2K05gt,
I like the sig you have. Take a lot of time to make it?
Thanks, No it took about 2 hours.
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Old 04-16-2007, 11:19 PM
  #24  
Foose12
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Default RE: UNDERDRIVE PULLEYS

ORIGINAL: 2k05gt

they are good for an gain of about 10 HP and a bit better MPG increase. less drag on the engine.
Do not install UDP if you plan on a Huge Audio System with Amps and stuff. also if you have the shaker 1000 system it might not be a good idea, other than that sure go for it, I love mine
Why? I wanted to do UDP's but plan on a lil extra boom in the trunk..
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Old 04-16-2007, 11:35 PM
  #25  
2k05gt
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Default RE: UNDERDRIVE PULLEYS

ORIGINAL: Foose12

ORIGINAL: 2k05gt

they are good for an gain of about 10 HP and a bit better MPG increase. less drag on the engine.
Do not install UDP if you plan on a Huge Audio System with Amps and stuff. also if you have the shaker 1000 system it might not be a good idea, other than that sure go for it, I love mine
Why? I wanted to do UDP's but plan on a lil extra boom in the trunk..
The more power you draw from your electrical system the harder the alternator has to work to keep the battery charged, if you plan to use your boom trunk while driving you will not have an issue, if you plan to sit at idle while your trunk booms then you may have a charging issue. I have a 600 Watt 10" kenwood bass tube in my trunk and I have no problems, I am talking about 2000 + watts with 2 12" subs and 15 speakers on your back dash and a little bobbing dog watching everybody pass.

read odiaz comment
ORIGINAL: odiaz

The UDPs do slow down your alternator but it only affects it's output at idle. The output curve on an alternator is not linear, it tops out at about 1000-1200 RPM. What that means is that with the new pulleys, you would have top operate at 1250 RPMs to put out the same power as with the stock pulleys. After 1250 RPMs, the output of the alternator is the same with the old or the new pulleys.

The net effect is that unles you plan to operate all of your electrical devices at idle, having a set of UDP poulleys is not going to affect the operation of your electrical system at all. So go ahead and add the UDPs if you think you can benefit from the extra 10 HP. The difference is noticeable immediately.

The installation is not difficult if you ha the right tools. There are a few things to watch out for. Many say that you need to remove the fan showd and fan for better clearance but I've found that its unnecesary if you use a 4" stubby impact wrench. Sears sells them.

I wrote up the entire procedure and posted it here.

http://www.cherod.com/mustang/HowTo/Pulleys.htm
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Old 08-03-2007, 12:06 PM
  #26  
0NF1R
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Default RE: UNDERDRIVE PULLEYS

nice........
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