SirKnightTG

Wait a min, I didn't know FRPP made a UDP????

Batenswytch

They may be Roush. I can't remember - they're still in the boxes back in the den. LOL

jodadejss06gt

I had UDP on my v8 Jeep GC with a true 350W amp powering the sub and even that drained my battery back a few years ago. I only took real short trips at college too so that could have also been a factor. If you drive a decent amount of miles at once to give a good slow charge on the battery it should be fine. Its just the 5 milers with the sub thumping that messed me up.

Nuke

A lot of sitting in traffic idling with some heavy duty power demand (hi power amp, A/C, headlights, fog lights, etc) and having UDP's COULD be a problem since the alternators output is at it's lowest at idle. But others here that have been asked previously claim they have NOT had issues.

Batenswytch

Awesome then. The drain I noticed on my fox takes about a year or so before the battery won't hold a charge anymore, and I didn't know at the time the UDP's were probably causing it. Now that I know though? I can just put it on a battery charger every so often. I did have it recommended that I put an alternator from a 94 on it, just change the pigtail.

But getting back to the 06 - I do believe those are Roush. I didn't double check this morning, but the more I think about it, the more certain I am they are Roush. And I had hoped the S197's had a better alternator on them than the 91-93 Foxes. ;-)

nicknitro25

pretty much this

dragrace4fun80

To respond to the previous post on it, my amp isn't involved in the Shaker system. It's a stand-alone...I'm running 2 MB Quarts in a custom sealed box, not even cranked, but I don't think an amp should have to strain on a good box/speakers, so having more doesn't hurt. I need to get a better amp, but I don't need a 1kW RMS amp anyway, as I don't need THAT much bass. Off subject, though. The UDPs will be worth it as a small bonus that can add to the list which add up to a lot later, as stated! I do say again, though, that I have not had a problem with the charge of my battery ONCE since the amp's been installed two years ago. I keep track of the voltage on my cap every time I open the trunk and it's been normal as always.

q8stang

the way the alternator works in our cars when you install udp the alternator will spin slower in turn will need to work more to achieve the required out put voltage which means it will use the 4-5 hp that you think you freed up

Nuke

You sound like most of the techs at the dealership...

UDP's do NOT cause the alternator to work harder. Under extreme electrical demand, the alternator's CURRENT output may not be high enough at idle with UDP's but the battery will take up whatever slack the alternator can't provide.

I'll show you MY electrical engineering degree and 33 years of experience if you show me yours.

NOTSTOCK

+1 I am also keenly aware of power supply/demand issues. The alternator doesn't "work", it's just a generator that produces electrical current based upon rotational speed as reacting to the internal magnets...i think As nuke said, if you have a really high power demand you might be in trouble, but for the normal stuff you should be ok. Mine are on order.