What is the difference between the two? do they both add the same amount of horsepower? does one fit better than the other? do they both bolt right on without modifications? if i were to get one, which one would best be for me.....99 auto max?

 

Save your money.

 

Yes I agree. I have one but it was pretty much given to me. It did emphasize something (free'd up maybe 1 hp). It does add an interesting sound to the engine rev. But I have read too many scary posts about them breaking and destroying the bottom end. Don't buy one. Invest in a YPipe, and/ or 00vi conversion.

 

the difference is the diameter/weight. the stock size does not underdrive your accesories and is supposed to add hp strictly by reducing the weight. the underdrive pulley is supposed to free up hp by underdriving you accesories, which supposedly rob some power, as well as reducing weight.

i'm not sure that either do anything.

 

^^^^^^^^^?????? wut do u mean by 00vi conversion?

 

thnx guys for the info, i was just making sure wut they do, so i guess i will stick to a y-pipe or going with a jet pcm. cause i really need some pick up on my acceleration, i know the pcm will help with that

 

Ive had mine for 6 months and notice the car running smoother. It deff. helped with the HP. freeded up some HP allowing the lightened flywheel to make the tires screem!!!

 

History disagrees with you.

 

i don't think the jet pcm is a great upgrade either.

 

I don't know how I missed that.



Listen to this man! ^^

 

Placebo effect at it's finest.

 

placebo my a**

 

I'm not saying that there wasn't a difference in performance in the lower gears. I'm saying that it had nothing to do with the UDP and had everything to do with the lightened flywheel. UDP's, historically, don't do much.

 

Ide like to believe its the combination of both of them in that case.

 

Believe=placebo effect

Believe all you want, but based on your post, you added the UDP to your car that already had a Fidanza FW on it, and then your car ran smoother and made "your tires scream".

That's what I call Nothing more than Placebo effect.

The FW is doing 99% of what you're experiencing, with the difference going to the UDP. There's your combination.

 

Uhhh thanks for caring so much. Urr swell, but really. Whatever improvment i noticed im going to have attribute to the udp, since it is the most recent upgrade. Maybe i should of added "more" at the end of my first thread where i said it freed up hp allowing the fw to make the tires scream, but i figured it was obvious with a 5 spd.
Yes the car did idle smoother too thanks

 

:attention

 

Sorry dude i like the under drive pully my car idles quieter. I dont notice any power loss either to any of my instruments although they are all stock. There is also a HP improvement

 

well my car is auto 4 spd and urs is 5 spd would and is there a difference?

 

that i couldnt help you with I dont know if there is a difference, im sure there is though. It will definitely make the car run smoother, google it and read up the comments would b my best bet

 

yea good advice, anyone else wanna add anything, or know anything about my previous question?

 

invest in other mods... however if you do get a lightened pulley, stick with stock size. a big majority of the hp gain (if any) comes from the weight reduction where very little comes from the smaller diameter. this way you are not underdriving your alternator and your ac compressor

 

ok, cool, thanks man

 

UDP does free up power but it is for someone looking to get everything out of there car. I have tested it for my self... me and my buddy have the same year (95) autos. Stock to Stock i was faster by maybe 10 inches. His first mod was udp and he pulled half a car or less on me. So it does free up power.

 

Who makes them still?

 

unorthodox racing makes the only stock size one i know of.

 

I bought one, it through my crank off balance and it did not work

 

No dyno proof, no care.........

 

yeah i agree with dblock1 i did have my oem FW shaved and added a udp..w/ypipe, had no traction at all specially in 1rst all the way to the early 3rd gear if had a good launch.. and i was using 235s on my 16" rims. put one in my automagic max and i am not lying dude, it does make a difference but u ve gotta wait for a week or two to get the timing adjusted....

 

Unless its going to be a full blown track car, its pointless to spend that kind of money on such a minimal gain.

 

udp is like the cai debate. just save yourself the trouble, risk, and money and spent on something better

 

Hook me up with the cash i will dyno it.

 

+1 ^ i hate mine. Car came with them since i got it from tilley but he wasnt using the a/c and my a/c sucks with thoes pullies on there. And i know its not the a/c thats bad he installed a new on and i had it charged and everything.

 

so i guess i will have to pass on that, thnx guys :-D