I have talked with a friend of mine and told him that when my 06 gets here I have a lot of mods that I would like to do to it, including underdrive pulleys. In my opinion it frees up horsepower...how much im not sure but every bit counts. He says that underdrive pulleys have a negative affect on your alternator/accesories. Is this true?

So I guess my question is (to get to the point)

Do underdrive pulleys have any negative impact to any part of the car?
How much horsepower does underdrive pulleys give you back?

 

I have had underdrive pulleys on my 97 Cougar 4.6 L for 6-7 years now with absolutly no negitive impact on any part of the car/ motor. The only down side I have seen is that when I am in gear at idle, the alt. does not charge the battery, but if I pop it into neutral, I get a full charge. So, if I am stuck for a LONG time in traffic or what not, I just put it in neutral or park and no problems.
The 3V 4.6 should be the same or really similar.
As for HP gained or freed up, I don't know an exact number, but the seat-o-the-pants meter says 10-15 at mid to full throttle, or it could just be the greatly improved throttle responce that makes it feel that much quicker.
Hope this helps, I would put underdrive pulleys on mine in a heartbeat and never think twice about them.

Scott

 

Just don't put a monster sound system in. The 2 just don't mix.

 

Well I wont be putting in a monster sound system, I will have the Shaker 500, also may be replacing the Deck with a Kenwood or pioneer DVD NAV unit. Think that would cause a problem?

 

I have been running them on my 05 for several thousand miles now. No problems. I have a 500 and a Sirius powerhead running all the time. I also live in Yuma AZ. Never a issue.

 

Sorry to twist the topic a bit, buthat does the Sirius thing look like? I want it in the car, but would rather not have the Sportster thing sticking up somewhere...

Mike E

 

I have underdrive pullys and 2 12" subs running off an 800watt amp in my 96 tbird. Its not a monster sound system, but it pulls some good power. I haven't had any issues at all except at idle it charges a little less than it did before. Had the pullys and radio in it for 4 years now and battery has never died.

 

Hmm well, im not one that likes the heat....one thing I love about the stang is the absolute powerful AC it seems to have in it, If the pulleys will make the performance of the AC go down, .... since im looking at possibly getting a Vortec S/C in the future I might want to just get a CAI and tuner for now.

Not to mention exterior mods....

Such as the gefracing.com legend body kit.

 

If you are using an SCT or Predator tuner, you can also up the idle by a few hundred rpm's to make up for any loss at idle (though it is more a theoretical issue than one in practice from what I've read--I'll be getting them ASAP).

 

I have a Sportster. It is mounted on the very back of my center counsel. You can not see it unless you are in the back seat. It is hard to adjust while driving but I leave it on the same station anyways.

 

The worst you will likely see is power steering effort on the whimpy side at idle and parking or otherwise turning tight. If alternator does not give juice at idle, you should be okay for several hours. Coolent flow will be down slightly ... would likely not see any problem except under the most extreme loading high temperature conditions ... and even then, the system has some safety margin.

 

I had issues with the crankshaft wobble sensor, and I did remove them and reinstall them correctly to ensure this was not the problem. It ultimately led me to sell them, I will be adding a supercharger so it wasn't a great loss for me. If you get CEL's and your engine runs poorly from time to time while the CEL flashes you should take them off and return to the factory setup immediately. I purchased the Sean Hyland Motorsports pulleys, they were some of the first ones that they made so hopefully the issue is resolved.