Under DRive pulleys??

[likuidpop]

what exactly is a UDP i heard it is a very good mod to do on ur car.. can u help me out with what it is ... and where can i get one.. is it only for Turbos?

 

[wicked93GS]

ok, the cranksaft pulley drives the engine accesories, like AC, the underdrive pulley replaces it, and since the UDP is a smaller diamter pulley, the accesories spin slower, giving more HP to your engine or rather reducing the parasitic load of your accesories, however if you have a heavy drawing electronics system(like a 2000 watt stereo) its not a good idea, since it spins your alternator slower too, no, you can get them for NT too, but you have a different engine than the turbo(the 94 and before NTs had the same engine) you have a 420a engine, I believe that a UDP for a DOHC dodge neon 2.0 litre motor would fit yours, you can always go to unorthodoxracing.com and see if they have one for the 2g NTs, or nopi.com, they should be easy enough to find

 

[DSM-ZERO]

I have an AFX udp and it is a 30% pully and give you more HP it is about 10-15 to the wheels! the unorthodoxracing udp is 20% The AFX is 140$ go to www.howellautomotive.com

 

[senseiturtle]

An excellent mod. Comes highly recommended by just about everyone I know that has one. Give me a few days, and I'll have personal experience.. got an AFX sitting right here.

Damn that thing is light.

 

[dont need 8]

I have had a UDP for a few months now, I also have a modest two amp stereo (around 500 watts) and have had no ill experience in regard to electric power (ie blinking lights, slow starter) and haven't had an issue with belts squeeling or fraying/breaking. It was also a noticeable acceleration increase. Adding at least as much power as my cold air intake, maybe more.

 

[Bohica]

You will also experience a reduction in your accessories. Power steering is a bit slower, etc.

But not only does it help because it doesn't have to spin as much, it also helps because every underdrive pully you see will be much much lighter. The stock pulley is probably steel, and most UDPs are 6061 aluminum, and they have lightening holes in them. This reduces the rotating mass quite a bit, meaning that it will require less power for your engine to spin it up to speed. (helping in acceleration)

From my experience with UDPs, you can't go wrong.

 

[kamakazy59]

I heard that the UDP on the 420A eliminates a part that is there to stop violent shaking of the engine during high revs, i heard becuase of this the UDP cuases problems a little ways down the road. I would love a UDP but scared of what i heard anyone have one for a year or so????

 

[senseiturtle]

""UDP
I heard that the UDP on the 420A eliminates a part that is there to stop violent shaking of the engine during high revs, i heard becuase of this the UDP cuases problems a little ways down the road. I would love a UDP but scared of what i heard anyone have one for a year or so???? ""


In the research I've done, I haven't heard anything along these lines. The only thing I have some idea of is something known as a balance shaft on the 4g63's. I'm sure the turbo guys around here could verify that..

I dont think that the engine will shake violently, just from the physics of it. If the pulley was well designed and balanced (like a centrifuge), then it could spin MUCH faster than 7000 rpm and not give any problems. Any violent shaking would probably be the result of loose belts or not torquing the pulley to 105 ft-lbs. I'm about to install my UDP, and I'm not worried in the least..

The biggest problem I see is getting the old clunker off... whoopee.

-ryan

 

[dont need 8]

Originally posted by kamakazy59
I heard that the UDP on the 420A eliminates a part that is there to stop violent shaking of the engine during high revs, i heard becuase of this the UDP cuases problems a little ways down the road. I would love a UDP but scared of what i heard anyone have one for a year or so????

You have been misinformed. The only part that the UDP replaces is the old pulley. When I purchased mine all that was in the box was a pulley and two belts. Most everyone on this site, 2gnt, Southeast Chapter of Club DSM, and DFW DSM swears by them. Just make sure that you install it correctly. The only issues I have heard are from poor installations.

 

[kamakazy59]

maybe thats what i read about someone that had not installed it correctly, thats cool i thank you guys for letting me know ! I definatly want one now, thanks guys.

 

[SniperXr2]

I have a 97 Eclipse N/T, how much do you think a UDP would cost for my car?, also I want to start rebuliding my 420A, and then turbo charge it, i was wondering if anyone could give me some suggestions as to what parts i should go for in the engine and maybe give me some prices. Thanks
-Rob

 

[senseiturtle]

see my response to this thread.

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=40671

later

 

[eclipse13]

thanks for the info