nvrblue13

To those with under drive pulleys.... do they make a big difference and do you notice the power. i have seen claims up to 12 hp? will this compliment a tune at all? looking at an sct tuner and wondering. does it kill you a/c alot also. buy alot i mean to wear the 2-60 is a better option.

Alec

Bump for interest

Nuke

I think they're worthwhile. On the GT they're good for about 4-6 RWHP from what I've seen. That's seat-of-the-pants dyno realm. No tune required and even those that do a lot of stop-n-go driving haven't seen any negative impact. BUT... my g/f has an '06 V6, totally stock and did a lot of stop-n-go, very short distance driving and I have to admit that I was concerned about her cars ability to charge the battery. Now that I moved her where she drives longer distances her battery seems to be in a much better state of charge. I think I'd have been concerned with UDP's under her circumstance. But I'm SURE her problem was due to those stop-n-go, less than 1 mile trips. Little chance for the battery to recoupe the starting discharge.

nvrblue13

"On the GT they're good for about 4-6 RWHP from what I've seen. That's seat-of-the-pants dyno realm."
^idk if you being sarcastic or not. i would probably buy a whole kit with an overdrive pulley on the alternator. i do a lot of long distance driving so it wouldn't be a major issue for me.

Nuke

I told you as I see it based on over 3 years of forum member feedback plus other off-site data. Take it or leave it.

pascal

No wonder she'd be on the low charge side...
It takes approximately 4 miles at normal driving to recharge back from one crank of the starter.
Today's batteries and alternators are a little more efficient but I'm sure that 1 mile is still too short to recharge at max level.

2005Redfire6

Sounds more like a hassle then its worth.

2007 grimlock stang

For all N/A V6ers, go buy and install ASP's UDP. Yes. It IS a noticeable improvement. Similar gains on the V6 which makes sense since we're both basically running the same accessories?

But yep. I noticed it the day I pulled outta JBA. No A/C, battery, or any other issues for > 3yrs now. Heck, I'm even running an 11lb Deka battery to boot!!!!!

Oh, no tune alterations required. The only thing required with this is a belt swap. You'll need a shorter belt, but ASP provides the correct replacement info.

tigercrazy718

alright about time someone with udps spoke up lol
i know someone else on here got them recently but was waiting to install them
now the question obviously is whether its worth 250 for it
and if you eventually go F/I you cant use these huh?

2007 grimlock stang

I guess it all depends on what it means to you. Kinda like how someone would spend $2000 on a Star Wars action figure or comic book and feel that they got exactly what they wanted out of it.

For me, no toy or book is worth that much. For my Mustang, the boost in the seat-of-the-pant's feel and the fact that I'm keeping the car N/A means every penny was worth to me. Actually, the only regret I have thus far with all the mods I've done, is that I wish I woulda gone with a JLT CAI for the few extra ponies over my K&N but right now, the cost doesn't justify itself for me LOL!

I actually love the quality of the K&N and the ease of maintenance, fit, finish, etc. etc.

So in the end, yes. For this MFer, the cost of the UDP was worth it. And driving around having fun for the past 3 years has paid for itself by now ;P