Underdrive Pulley Systems & Aftermarket Audio: Bad Idea?

[Psycareyo 10+ year member]

Does anyone here have experiance with underdrive pulley systems? I'm thinking about getting a set for my Sport Trac Adrenalin. I think it will complement my other mods well but I'm concerned for my aftermarket audio system.

I have the stock alt and I will be using a small 60.4 front stage and a small 300.1 substage.

I want to buy Steeda's S197 Underdrive Pulley System - '05-'09 part number 555-3305.

It will fit my vehicle perfectly. It's a 25% UDP.

I'm just really concerned that my audio performance will suffer. I can deal with a warmer AC and maybe even a little less power steering.

Click to read more...

 

[jco1385 5,000+ posts]

if anything, it'll make the alt spin faster = more power

smaller pulley = more revs = more power

//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

i'm pretty sure thats how they work. but i'm not 100%

 

[scoob8000 10+ year member]

Underdrive pulleys spin all your accessories slower, so yes you may have charging issues.

FWIW, pulleys are a waste of money. There's usually not even a noticeable SOTP (seat of the pants) gain.

What are some of your other mods? Cold air intake? If not, that would give you much more then a set of underdrive pulleys for about the same cost.

 

[DarkFire 10+ year member]

See if there is an overdrive pulley for the alt.

 

[Psycareyo 10+ year member]

Underdrive pulleys spin all your accessories slower, so yes you may have charging issues.
FWIW, pulleys are a waste of money. There's usually not even a noticeable SOTP (seat of the pants) gain.

What are some of your other mods? Cold air intake? If not, that would give you much more then a set of underdrive pulleys for about the same cost.

I have a FIPK, Bored out throttle body, 93 Octane ECM Dyno tune, straight through exhaust w/ cutout.

I've decided against the UDP. Just not willing to let anything more go to gain a few hp. I'm pretty happy where it's at now.

 

[96MaxGLE 10+ year member]

Yes it will cause charging issue like the other guy stated in his post. I bought a lightweight stock size pulley for my Acura. I have yet to install it, but have seen multiple dyno runs before and after showing 6-8hp gain...the UD pulley showed 7-10hp. I'm sure the differences will vary from vehicle to vehicle, but for $190 and seeing the dyno for my vehicle...I couldn't pass it up. Every little gain counts //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Shadow7874 10+ year member]

I would go with e-h2o pumps before udps. Im in the same situation though, ive got a s197 (07 mustang gt) and udps were one mod ive considered, but decided against. Maybe down the road ill change my mind, but there are better ways to make power gains without sacrificing as much.

 

[badvlvo 10+ year member]

They are an OK mod for the money. I noticed a difference in the engine response at higher rpm's in my Mustang, Volvo and F250 with underdrives. You can get a smaller pulley for the alt to keep the alt speed the same while slowing the p/s, a/c and water pump.

It's easy and cheap, do it. If you don't like it sell the ish on fleabay and spend it on something else.

 

[buurner 10+ year member]

See if there is an overdrive pulley for the alt.

I will agree if you have audio overdrive ur alt and uner drive your crank. Since my car is built more for racing I had to do it and it works fine even with a 2000 watt amp and all my electronics for my motor.