Underdrive pulley

[er00msivarT]

Hey guys i did a search but i couldnt find what i was looking for. Do you guys recommend the AF/X or the Unorthadox pulley. I have a belt or pulley chattering and i might be replacing this so i was just wondering which one you guys think is better. Thanks for the input.

I forgot to ask. The belt by the antifreeze resevor (sp?) is the ps/ac belt correct? What other belts do we have besides the Timing i just replaced the Timing belt. Im almost sure its the ac/ps belt that is squeeking. What else does this belt control? I have put that belt crap on there, but it keeps squeeking so i need to replace it. Also is it hard to do or will a shop need to do it? About whats the average time to do it. Thanks guys

 

[FreStylMotoX01]

The AFX one is nice makes a decent difference at least noticable. i would highly recommend it. i have heard of people complaining that it squeaks but i haven't had a problem yet and it has been a few months. i was able to get it for 130.00 shipped and 97 to get it installed.

-Jon

 

[eclipse13]

I forgot to ask. The belt by the antifreeze resevor (sp?) is the ps/ac belt correct? What other belts do we have besides the Timing i just replaced the Timing belt.

Yes, it is the PS/AC belt. Those are the only things that it controls. It takes me about 15 minutes to replace that belt, but I have done it numerous times because my pulleys were misaligned at one point.

The crank pulley has 2 belts coming from it. One is the PS/AC belt that you have seen, the other is the alternator belt that goes toward the back of the engine. The only other belt is the timing belt.

I have the AF/X underdrive pulley. I defentnly noticed a gain after I put it on. It took me about 2.5 hours to install and I am 17 years old with limited experiance with cars. I used a lift and had an amazing amount of tools available, so it may take you longer depending on your ability and what you have available to you. Oh, and I used the instructions from the tech section.

 

[GSGoinFast]

Yes, it is the PS/AC belt. Those are the only things that it controls. It takes me about 15 minutes to replace that belt, but I have done it numerous times because my pulleys were misaligned at one point.

The crank pulley has 2 belts coming from it. One is the PS/AC belt that you have seen, the other is the alternator belt that goes toward the back of the engine. The only other belt is the timing belt.

I have the AF/X underdrive pulley. I defentnly noticed a gain after I put it on. It took me about 2.5 hours to install and I am 17 years old with limited experiance with cars. I used a lift and had an amazing amount of tools available, so it may take you longer depending on your ability and what you have available to you. Oh, and I used the instructions from the tech section.

did you use mine or the one from 2gnt.com? if mine was it good or is there stuff missing?

the unorthadox is overpriced, when the afx is just as good. i have some belt squeeking issues too but thats partly because i forget to tighten them after they break in a little bit.

 

[jwreed09]

i have the unorthodox pulley...it was a bit pricey. i was going after the af/x but they weren't in stock and had to wait a couple weeks! but most def go with the af/x. the unorthodox udp has 20% dampening and the af/x has 30%. good luck with your choice...and when ya get the pulley you have to get smaller belts as well. atleast i had to on my udp! good luck....

 

[er00msivarT]

Hey guys thanks for the help. I think either just my belts our my pullies/tensioner is squeeling. So im going to replace my belts. What belts do you recommend to replace the factory belts? I put more PS fluid in and mmy car is still squeeking so it is more then likely my belts correct? The belts have never been replaced but they seem in good condition from the ps/ac belt. Any input would be great. Thanks guys

*edit* is there a FAQ or anything i can print out on how to change the belts and how to tighten them. Thanks guys

 

[gsx951]

Undampened underdrive pullies are bad voodoo. Do not install one.
If you insist, allow me to sell you one that I'm no longer using.

The crank is from a 2.3 short block done by VT competition engines. The internals are JE, Oliver and a Mitsu 100mm crank. A balanced and professionally assembled motor.
I was using an Unorthodox Racing underdrive pulley at the time.
The underdrive pulley mod is every bit as bad as the barometric sensor mod.
Do some searching.

 

[eclipse13]

^^^On the 420A the non-dampening UDP isnt much of a problem as it is with the 4g63.

er00msivor- If you get the AF/X pulley, the new belts come with it, so if you are planning on doing it, dont spend money on new belts just to turn around and replace the pulley and belts again.

GSgoinfast- I used yours, I meant to PM you and thank you but I might have forgoten to. it was a great step by step. My dad has replaced a 420A crank pulley before, so he helped alot, but i was reading your instructions the entire time and it they were easy to understand, they worked great, thanks.

 

[GSGoinFast]

^^^On the 420A the non-dampening UDP isnt much of a problem as it is with the 4g63.

er00msivor- If you get the AF/X pulley, the new belts come with it, so if you are planning on doing it, dont spend money on new belts just to turn around and replace the pulley and belts again.

GSgoinfast- I used yours, I meant to PM you and thank you but I might have forgoten to. it was a great step by step. My dad has replaced a 420A crank pulley before, so he helped alot, but i was reading your instructions the entire time and it they were easy to understand, they worked great, thanks.

ya like he said its not as bad for the 420a.

no prob on the instructions, im glad they helped. i just wish i had had a camera when i did the install. but im glad there still usuable.

 

[er00msivarT]

What if im not replacing the UDP what belts should i use then?

 

[gsx951]

^^^On the 420A the non-dampening UDP isnt much of a problem as it is with the 4g63.

Really? Based on what? Tha 420A crank is a casting and MUCH more fragile than a forged Mitsu crank.

 

[GSGoinFast]

Really? Based on what? Tha 420A crank is a casting and MUCH more fragile than a forged Mitsu crank.

well ive seen threads of turbo guys talking about how they only should get dampened pulleys, and they dont even make them for 420a's. many of us have them and i havnt seen any problems. i have one myself. a great number of us do and i havnt seen one problem like that.

 

[94Talon2]

Undampened underdrive pullies are bad voodoo. Do not install one.
If you insist, allow me to sell you one that I'm no longer using.

The crank is from a 2.3 short block done by VT competition engines. The internals are JE, Oliver and a Mitsu 100mm crank. A balanced and professionally assembled motor.
I was using an Unorthodox Racing underdrive pulley at the time.
The underdrive pulley mod is every bit as bad as the barometric sensor mod.
Do some searching.

Not sure about the 420a, but I had a unorthodox, and we think that is what caused the wear on my crank. I would like to contact unorthodox, but how can I prove it.

 

[gsx951]

well ive seen threads of turbo guys talking about how they only should get dampened pulleys, and they dont even make them for 420a's. many of us have them and i havnt seen any problems. i have one myself. a great number of us do and i havnt seen one problem like that.

Yep, I thought like that too but if you search, You'll find a fair amount of data on the issue and may change your mind. I would hate to see you in the place I was: a big dollar motor with just 9,000 who's crank was miles busted in two.

 

[GSGoinFast]

Yep, I thought like that too but if you search, You'll find a fair amount of data on the issue and may change your mind. I would hate to see you in the place I was: a big dollar motor with just 9,000 who's crank was miles busted in two.

well, look what i found

But in reality the weight of the underdrive pulley is so little, and is cut from a stock piece of aluminum which should have very little variation in desity across it, there's no balancing issues.

And onto our stock crank pulley... it's is much heavier so any variations in density it has would have greater effect on the crank. Putting all that aside we don'e have a harmonic balancer. Our crank is internally balanced not an external balance like the 4G63. They have a harmonic balancer, which is a keyed to the crank because it purposefully balanced to help reduce vibration and help the crank move along.

For the 420A you don't want something offset weighted. You want a pulley as close to uniform density as you can get. AFX and Unorthodox CNC cut the pulley's from stock aluminum, how much more precision are you looking for? There will be NO engine damage from running either AFX or Unorthodox Pulley on your car. It's not like putting an unbalanced pulley on a 4G63 or an old Chevy V-8 that has a harmonic balancer pulley.

its from 2gnt.com written by a moderator. i think that settles it.

 

[gsx951]

Not sure about the 420a, but I had a unorthodox, and we think that is what caused the wear on my crank. I would like to contact unorthodox, but how can I prove it.

David Buschur posted info about that years ago. I found out first hand....Yes you get weird bearing/crank wear
The crank actually flutters in torsion and the damper reduces this oscillation.
This is one of those mods that newbies love because they can do it, it's cheap and actually does work but it's just not worth the potential failure of your crank.
I did it because iI was sick of replacing the O.E.M. damper that's prone to fail. In hind sight that was a bad call. You'll find a Fisher Concepts damper on my crank now.

 

[gsx951]

well, look what i found



its from 2gnt.com written by a moderator. i think that settles it.

Actually that's got nothing to do with it. This is not a balance issue.... it is an oscillation issue. Balance has absolutely nothing to do with what is going on here...nothing.

 

[gsx951]

Letter from Dave Buschur to Talon Digest Sept. 1998

Hello, I am not starting a debate again. As a matter of fact, if you have some questions send me a private e-mail. I do have some facts though. First let me say, yes, I have been running an Unorthodox underdrive pulley for about a year. I have had no problems that I can blame on the pulley, they are nice and they are cheap. If they do pick up 10hp like Turbo Magazine says they do then they are a bargain. Now to my point. As alot of you know I have been working with a company to have some custom dampers done with the underdrive built into them. They are finally done and I have done the final testing. We have had the first unit on and off the AWD a few times to get results back and the final settings have been made. After looking at the unit and getting the feedback from the shop that is building the units for us there is ABSOLUTELY NO doubt that these cars, just as we thought, have to have the damper on them. I have had some unusual bearing wear for the last year or so. The more I learn about dampers the more I understand that the problem was 99% related to the fact I have not been running one. We did end up keeping the underdrive unit in the damper too. So there is less drag and we get a superior damper compared to the stock unit. Now, everyone that has ever bought a performance part thinks it works, why? Well you just spent your hard earned money on it. I have done the same thing in the past I am sure. I am very skeptical nowadays. Well I took the damper off the AWD Sunday and put it on the RWD. Since it is the only one I have so far I wanted to swap it. The difference? Holy $h!t. The RWD engine is mounted to solid aluminum plates which are bolted directly to the frame of the car. The car vibrates so hard it goes up your spine, it also vibrates enough to readjust the rearview mirror just revving the engine. I cannot believe it but this is all but gone. I mean you can still feel the engine has some vibration, it has to mounted this way, but the majority of it is gone. I am going to be really curious next time we pull this engine down to see what the bearing look like. I have 10 more being shipped to me ASAP, they are built, the shop and I are just working out pricing. The first 7 are sold. This is the list of the guys first names (for privacy), you guys will know who you are, if you have changed your minds please contact me. I have three more available.


(stolen from the Stealth Zone.)
The Under Drive Pulley debate.

First off a few disclaimers: This page deals ONLY with the 3000GT/Stealth cars and Unorthodox Racing's under drive pulleys. I welcome differing opinions and will post anyone comments if they request. My only motivation for posting this is to give a heads-up to all people considering doing this mod. It seems that every month there is another person asking about the UDP's on the message board or starnet list and they need to have a clear view of the facts. My opinion is also included in this page.... take it for what it is worth. I don't want to tell anyone what to do with their car, just present the facts so they can decide for themselves.

Definitions used in this discussion:

Torsional vibration: Every time a cylinder fires, the connecting rod hammers the crankshaft, making it twist as well as spin. After every twist, there's a rebound as the crank unwinds. This twist/rebound cycle is known as torsional vibration and if not controlled, it will result in rapid bearing and crank journal wear and can lead to a broken crankshaft. ( Source: Fluidampr's tech pages. )

Harmonic balancer: The harmonic balancer, or vibration damper, is a device connected to the crankshaft to lessen the torsional vibration. When the cylinders fire, power gets transmitted through the crankshaft. The front of the crankshaft takes the brunt of this power, so it often moves before the rear of the crankshaft. This causes a twisting motion. Then, when the power is removed from the front, the halfway twisted shaft unwinds and snaps back in the opposite direction. Although this unwinding process is quite small, it causes "torsional vibration." To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft that's causing all the trouble. The balancer is made of two pieces connected by rubber plugs, spring loaded friction discs, or both.
When the power from the cylinder hits the front of the crankshaft, it tries to twist the heavy part of the damper, but ends up twisting the rubber or discs connecting the two parts of the damper. The front of the crank can't speed up as much with the damper attached; the force is used to twist the rubber and speed up the damper wheel. This keeps the crankshaft operation calm.
( Source: AutoInsight training program )

"To sum it up:

If you want to risk bearing failure or worse yet crank failure run a UDP on your car. I am not saying it will happen next week, or even next year but it will happen. In my opinion the extra 5-10 HP is not worth it. (note these numbers are guess's since no conclusive dyno results have been posted) Just the idea of removing something which is designed to provide protection to your engine is fundamentally wrong. Engine builders across the country will agree with me on that one. With other mods we do, it is a calculated risk and with proper care we can measure and control the power we add. With UDP's we have no way of measuring what is going on and that scares me. Take my opinion for what it is worth and good luck."

 

[94Talon2]

I totaly agree with that statement. I put my old pulley back on after I put in my rebuilt 7-bolt engine. My bearings had lots of wear and the crank was walking big time. I had unorthodox pulley on for about 15 mounths, before I had to rebuild it.

Anyone want to buy it?

 

[Danny_305]

ok guys i was about to buy a unorthodox crank ultra S pulley now im uncertain if i want to


is what this guy is sayign true or is it bs?

 

[gsx951]

is what this guy is sayign true or is it bs?

Google is your friend...

 

[er00msivarT]

You guys totally highjacked my thread . oh well.

 

[GSGoinFast]

Letter from Dave Buschur to Talon Digest Sept. 1998

Hello, I am not starting a debate again. As a matter of fact, if you have some questions send me a private e-mail. I do have some facts though. First let me say, yes, I have been running an Unorthodox underdrive pulley for about a year. I have had no problems that I can blame on the pulley, they are nice and they are cheap. If they do pick up 10hp like Turbo Magazine says they do then they are a bargain. Now to my point. As alot of you know I have been working with a company to have some custom dampers done with the underdrive built into them. They are finally done and I have done the final testing. We have had the first unit on and off the AWD a few times to get results back and the final settings have been made. After looking at the unit and getting the feedback from the shop that is building the units for us there is ABSOLUTELY NO doubt that these cars, just as we thought, have to have the damper on them. I have had some unusual bearing wear for the last year or so. The more I learn about dampers the more I understand that the problem was 99% related to the fact I have not been running one. We did end up keeping the underdrive unit in the damper too. So there is less drag and we get a superior damper compared to the stock unit. Now, everyone that has ever bought a performance part thinks it works, why? Well you just spent your hard earned money on it. I have done the same thing in the past I am sure. I am very skeptical nowadays. Well I took the damper off the AWD Sunday and put it on the RWD. Since it is the only one I have so far I wanted to swap it. The difference? Holy $h!t. The RWD engine is mounted to solid aluminum plates which are bolted directly to the frame of the car. The car vibrates so hard it goes up your spine, it also vibrates enough to readjust the rearview mirror just revving the engine. I cannot believe it but this is all but gone. I mean you can still feel the engine has some vibration, it has to mounted this way, but the majority of it is gone. I am going to be really curious next time we pull this engine down to see what the bearing look like. I have 10 more being shipped to me ASAP, they are built, the shop and I are just working out pricing. The first 7 are sold. This is the list of the guys first names (for privacy), you guys will know who you are, if you have changed your minds please contact me. I have three more available.


(stolen from the Stealth Zone.)
The Under Drive Pulley debate.

First off a few disclaimers: This page deals ONLY with the 3000GT/Stealth cars and Unorthodox Racing's under drive pulleys. I welcome differing opinions and will post anyone comments if they request. My only motivation for posting this is to give a heads-up to all people considering doing this mod. It seems that every month there is another person asking about the UDP's on the message board or starnet list and they need to have a clear view of the facts. My opinion is also included in this page.... take it for what it is worth. I don't want to tell anyone what to do with their car, just present the facts so they can decide for themselves.

Definitions used in this discussion:

Torsional vibration: Every time a cylinder fires, the connecting rod hammers the crankshaft, making it twist as well as spin. After every twist, there's a rebound as the crank unwinds. This twist/rebound cycle is known as torsional vibration and if not controlled, it will result in rapid bearing and crank journal wear and can lead to a broken crankshaft. ( Source: Fluidampr's tech pages. )

Harmonic balancer: The harmonic balancer, or vibration damper, is a device connected to the crankshaft to lessen the torsional vibration. When the cylinders fire, power gets transmitted through the crankshaft. The front of the crankshaft takes the brunt of this power, so it often moves before the rear of the crankshaft. This causes a twisting motion. Then, when the power is removed from the front, the halfway twisted shaft unwinds and snaps back in the opposite direction. Although this unwinding process is quite small, it causes "torsional vibration." To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft that's causing all the trouble. The balancer is made of two pieces connected by rubber plugs, spring loaded friction discs, or both.
When the power from the cylinder hits the front of the crankshaft, it tries to twist the heavy part of the damper, but ends up twisting the rubber or discs connecting the two parts of the damper. The front of the crank can't speed up as much with the damper attached; the force is used to twist the rubber and speed up the damper wheel. This keeps the crankshaft operation calm.
( Source: AutoInsight training program )

"To sum it up:

If you want to risk bearing failure or worse yet crank failure run a UDP on your car. I am not saying it will happen next week, or even next year but it will happen. In my opinion the extra 5-10 HP is not worth it. (note these numbers are guess's since no conclusive dyno results have been posted) Just the idea of removing something which is designed to provide protection to your engine is fundamentally wrong. Engine builders across the country will agree with me on that one. With other mods we do, it is a calculated risk and with proper care we can measure and control the power we add. With UDP's we have no way of measuring what is going on and that scares me. Take my opinion for what it is worth and good luck."

you obviously didnt read what i posted from 2gnt. we are talking about the 420a here. not the 4g63. we dont have a harmonic balancer in our accessorie pulley. we are not like the 4g63. your taking all this 4g63 stuff and trying to apply it to the 420a where it doesnt apply. read my post again, it has everything to do with what we are talking about and talks about the same thing your post did.

 

[GSGoinFast]

and the icing on the cake, Doug 99RS has the AF/X UDP on his car. he is the NT god and is a chrysler mechanic. do you think he would put that on his car if it was going to destroy his crank? i dont think so.

 

[speedy13]

doug hass spoken!