Underdrive Pulley - Good or Bad?

[Racer 007]

I personally don't think that the UDP is that great of a mod. The HP gains are minimal and I think that the cons outweigh the pros.

What do you all think about this?

[Griffin]

I have heard nothing put positive results from this mod. Drew shaved about .2 thenths off of his 1/4 et with it, if I'm not mistaken. Just get it and stop crying already.:asshole:

[Hans91GT]

I think Griffin loves that asshole smilie :) :asshole:

I personally have never had a problem with the UDP. I've used it for 20k miles (engine now has 107k) with running nitrous through it and the engine still runs like a champ. The only thing replaced on the engine was the valve seals and 60k stuff. It's sporting the original oil pump and oil pressure is still within spec. I was going to put a new oil pump on, but I'm not going to worry about that until I think it's really necessary ;).

[TNT500]

I don't know about the UDP, I have a 3sx lightened pully. I didn't think that the HP gains were that great. Also, my AC started to squeal after I put it on. If I could do it again, I would have waited and bought a DP instead. Just my .02

[theonlypheonix]

TNT500, try tensioning your belt to spec, that should eliminate the squeal.:D

Don't waste your money on just the DP, go with the headers from RPW. There is a group buy going for RPw SOHC and DOHC headers:car2: ;)

[Racer 007]

What kind of prices are we looking at for the DOHC headers?

I have a friend who placed the UDP on his VR-4 and now you can hear some noise from the engine everytime he turns his tires left or right. It's pretty annoying.

[TNT500]

Richard,
I think I had that problem too for a while. When I moved the steering wheel at a stop or slowly moving, it made a horrible noise and felt like I had no power steering. Turns out to belt was too loose. You probably would have thought of that by now though.
Phoenix-how do you move the tensioner to spec? The only thing that worked for me is moving it a 1/2" extender. Is it too tight or too loose right now? Also, I am currently wrestling with the header topic. I have been following the RPW thread on 3SI, and it sounds good. But now ek2 is making short and long headers that would eliminate the DP (or atleast thats what I think). The RPW headers sound good, but they are alittle out of my price range right now. I probably wouldn't be ready to buy untill around christmas. Would it be possible to buy then?

[Racer 007]

Originally posted by TNT500
Richard,
I think I had that problem too for a while. When I moved the steering wheel at a stop or slowly moving, it made a horrible noise and felt like I had no power steering. Turns out to belt was too loose.and that was it? All you had to do was tighten up the belts? I am wondering if he did that all ready.

[99VR4SupraHunter]

Bad Mod. Flucks up your harmonic balancer.

[TNT500]

All I had to do was tighten my tensioner. My problem was right after I put the pulley on, it felt like I had no power steering. When I was stopped and I turned the wheel, it vibrated and was hard to turn. This also happened when I was going slow. When I was going over 15mph it was fine. I noticed that there was alot of slack on the accessory belt. When I tightened the tensioner some, it fixed the problem. Now the problem is my air conditioning squeals. I think thats because its too tight. If that sounds similar to whats happening, you might want to check on the tightness of the belt.

99VR4Suprahunter- When you put on a aftermarket pulley they don't come with harmonic balencers (except for buscher racing), thus nothing to fuck up
:D. Ive heard the concept of engine damage due to pulleys, but there has been no proof of this happening. I agree with you that over time it will probably cause damage, but that will happen with almost all engine mods. I think by the time that happens I will probably be looking into an engine rebuild anyways:) . If you can find proof of imediate damage, please prove me wronge. I'd really be interested in your findings.
My question is if everyone says that its such a big gain and its so great, then why didn't I feel that much?

[Racer 007]

Well, I am going to go ahead and give this mod a shot. I will have Dynamic pop it in either this weekend or in a couple of weeks. I have heard a lot more good coming about this vs. the bad. The guys at Dynamic also recommended it so I have to listen to the experts.

Hopefully, I will feel some decent gains.

[Racer 007]

OMFG, that's all I have to say.

[Havok]

Originally posted by Richard
I personally don't think that the UDP is that great of a mod. The HP gains are minimal and I think that the cons outweigh the pros.


Regret saying that?;)

[Racer 007]

Definitely regret saying that.

[DJ Eric P.]

Well what's so good about it and what differences do you feel in your car.

[92es]

Isn't the 3SX pulley cheaper than the UDP? Therefore you spend less and have full accessory power while only being 3 oz. heavier. I would much rather have an OEM size pulley. I would think the belt would squeal with the UDP installed.

What are you guys experiences?

[Racer 007]

I don't have any problems with squealing or noise and I also don't notice any change in my accessory power.

[TNT500]

I had some squealing from the 3sx pulley. However, I hear that moving the tensioner to spec will fix that. Anybody know what the specs are for the tensioner?

My own opinion on the pully is that you don't get nearly as much power from the 3sx pulley. Everyone that has a UDP says they have break neck performance. Most everyone with the 3sx says they didn't really feel it. I think that if you don't have a significant stereo, then go for the UDP. By the way, the dimming lights problem with the UDP can be fixed by raising your idle slightly, or so I've heard.