Why you SHOULDN'T get underdrive pulleys
#3
"In an attempt to minimize this energy loss, many companies claim to produce additional power by removing the harmonic damper and replacing it with a lightweight assembly".The pulleys I saw for our engines are "harmonic balancers" albeit a different design than Fords. Now I can see where a problem could develope if the weight of the inertia ring has been reduced significantly or the bond fails . These types of manufacturing flaws cause problems with the crankshaft among other components. Just a side note the original chevrolet small block engine wasn't equipped with a harmonic balancer at all, the engineers added it after a small harmonic was noted in the passenger compartment during testing. If an engine is an externally balanced engine (which the 4.0 is not) then you would be very foolish to change the balancer to smaller design. Folks have been changing balancers on engines for years, balancers that are significantly different than the factory design. The bottom line is this, if you can't afford to break it while searching for HP you shouldn't be in the HP game in the first place. Modifications always involve a certain amount of risk, you either accept it, or leave it stock. Just my opinion.
#4
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#5
If I'm not mistaken, are not the UDP systems for the 2005 Mustangs all use a Harmonic Balancer type of UDP? Meaning the crank pulley is still harmonically balanced, accept it is just less in diameter?
Which means, this particula article would not apply to the 2005 Mustang UDP's V6 or V8?
http://www.mustangtuning.com/bunpu.html
Now I could be wrong.. Howver, looking at all the UDP's for the 2005 Mustangs, V6 and V8, the crank pully is still an harmonic balancer, its just less in diameter...
????
I doubt ver seriously Steeda would invovle themselves in creating a UDP system that would destroy an engine...
I dont think this article applies to the 2005 Mustang's... Atleast not to UDP systems sold by Steeda, and some other well known outfits...
Looking at this pully system, thats an harmonically ballanced pulley... Look at it...
http://www.mustangtuning.com/stunpusy2gt.html
Enlarge the picture..
Which means, this particula article would not apply to the 2005 Mustang UDP's V6 or V8?
http://www.mustangtuning.com/bunpu.html
Now I could be wrong.. Howver, looking at all the UDP's for the 2005 Mustangs, V6 and V8, the crank pully is still an harmonic balancer, its just less in diameter...
????
I doubt ver seriously Steeda would invovle themselves in creating a UDP system that would destroy an engine...
I dont think this article applies to the 2005 Mustang's... Atleast not to UDP systems sold by Steeda, and some other well known outfits...
Looking at this pully system, thats an harmonically ballanced pulley... Look at it...
http://www.mustangtuning.com/stunpusy2gt.html
Enlarge the picture..
#6
This pulley for the 2005 V6 is also Harmonically balanced!!'
http://v6mustangstuff.com/images/asp05v6.gif
http://v6mustangstuff.com/images/asp05v6.gif
#7
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Originally posted by MSP@January 11, 2006, 8:42 PM
This pulley for the 2005 V6 is also Harmonically balanced!!'
http://v6mustangstuff.com/images/asp05v6.gif
This pulley for the 2005 V6 is also Harmonically balanced!!'
http://v6mustangstuff.com/images/asp05v6.gif
#8
Sorry for the poor quality photos... forgot my camera and had to use my phone... LOL!
![](http://www.tammyandjohn.com/Mustang/Screaming/Images/ASP6.jpg)
![](http://www.tammyandjohn.com/Mustang/Screaming/Images/ASP5.jpg)
While I will say the ASP claims for HP gains might be a little exaggerated I would doubt they would be able to stay in business very long if their pulleys started destroying engines... The ASP pulley is identical to the stock except for the diameter... the reason the shafts look differnt, (looks like the ASP has a lot shorter shaft) is because there is a plastic ring that was removed from the stock pulley and put on the ASP pulley...
So far no charging problems, no temp problems and no steering problems... only thing I've noticed is on a cold startup the belt will give a quick squeek...
![](http://www.tammyandjohn.com/Mustang/Screaming/Images/ASP6.jpg)
![](http://www.tammyandjohn.com/Mustang/Screaming/Images/ASP5.jpg)
While I will say the ASP claims for HP gains might be a little exaggerated I would doubt they would be able to stay in business very long if their pulleys started destroying engines... The ASP pulley is identical to the stock except for the diameter... the reason the shafts look differnt, (looks like the ASP has a lot shorter shaft) is because there is a plastic ring that was removed from the stock pulley and put on the ASP pulley...
So far no charging problems, no temp problems and no steering problems... only thing I've noticed is on a cold startup the belt will give a quick squeek...
#9
Originally posted by Jimp@January 11, 2006, 5:04 PM
I personally wouldn't chance it for a few extra HP. You'd hope that they are as good as the stock balancer but you don't really know.
I personally wouldn't chance it for a few extra HP. You'd hope that they are as good as the stock balancer but you don't really know.
But if it is slightly off, then things can go wrong.. I highly doubt any company making these things would chance a reputation and their business , by making them atleast not as good as stock...
I say its a good investment.. I would do it.. I've put UDP on all my other mustangs, and would consider this.. However in my current situation, putting a UDP on now without checking the rotational differences could mean disaster for me.. So I'll keep the stock pully for now... Atleast until I have the ability to understand the rotational offset it will send to the S/C... For me, the UDP will mean more boost.. How much I dont know... This is why I would have to find out, or atleast get to a point of understanding before I start changing pullys...
I know there is nothing to worry about though Jimp, so I would support you getting one without hesitation..
Also Pulley is the correct spelling.. I dont feel like changing it though.. LOL!!
Looking at Scrmings picture though, it sure does look like there is more metal on the stock pulley though... HMMM!!
Scrming, can you weigh both the pulleys? I would think they should be about the same counter weight.. Atleast mathimatically, they should weigh close to the same thing...
#10
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Originally posted by MSP@January 11, 2006, 11:20 PM
I highly doubt any company making these things would chance a reputation and their business , by making them atleast not as good as stock...
I highly doubt any company making these things would chance a reputation and their business , by making them atleast not as good as stock...
#11
Originally posted by P_Kiley@January 11, 2006, 8:26 PM
By extending that theory, nobody in the performance industry would ever release a bad product. I think it's a dubious assumption to think that mistakes don't sometimes happen, even with the best intentions.
By extending that theory, nobody in the performance industry would ever release a bad product. I think it's a dubious assumption to think that mistakes don't sometimes happen, even with the best intentions.
Good point!!
![Thumb](https://themustangsource.com/forums/images/smilies/thumb.gif)
What Scrming can do is weigh them.. Unless its already on his car... But I would guess they should be very similar in weight... If the new pulley is not as heavy as the stock one, then we may have a problem which needs to be looked into...
![Dunno](https://themustangsource.com/forums/images/smilies/dunno.gif)
Based on that picture, when viewing them both from the backside, they looked to be similar in wieght.. However from the front, looking from the center out, there appears to be a bit more metal on the stock pulley.. This could have been made up for by adding it to the back...
I just want to know how much or how close in weight they are.. If thats not a problem for scrming to do...
If its on the car scrming, dont worry about it... We can have Doug904 at Bamachips weigh them when he has a chance..
#12
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Originally posted by MSP@January 11, 2006, 10:20 PM
Thats the only key... Is it balanced as good or better than stock... If its balanced as good no problems.. If its balanced slightly better no problems..
Thats the only key... Is it balanced as good or better than stock... If its balanced as good no problems.. If its balanced slightly better no problems..
I kinda disagree (just a opinion) as I'm pretty sure any of these will be exact same balance/imbalance as required for the engine- the difference - and reason for that article- I believe is not balance at all- but harmonic damping- how much mass in the inertia ring and durometer/thickness of elastomer...tortional vibration is nothing like rotary imbalance vibration- you dont feel tortional vibration, its just the 'springy' response of the crankshaft to the power pulses- what effects that is the size of the flywheel attached to it, and how much flex is allowed in its coupling to the crankshaft. If the flywheel is smaller it will absorb less energy, and if the elastomer is not 'tuned' it could actually worsen the tortional vibration rather than reducing it(this would also reduce HP).
would be nice to fwd that article to 'fluidamper' and see what benefits they have, and just how much science goes in to tuning out resonant frequencies...I have heard of both power gains and reduced crankshaft stresses using their dampers - most have bolt on pulley that wouldnt effect too much- mustang setup *looks* to me like pulley IS the damper body?
#13
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Originally posted by MSP@January 11, 2006, 10:29 PM
What Scrming can do is weigh them..
What Scrming can do is weigh them..
#14
Like the article said, most people do not understand the physics involved. I don't either. Ford4v429 makes a good point. The article is not talking about mass but other issues. Steeda sounds like they have a good handle on this concept when they built the GT's UDPs. I would consider the source of the product. Does the company have an engineering department?
#15
Ok... now you guys are starting to scare me! All this physics talk... Can't week talk about World Wide Numbers and 4 Gigabit Fabric and soft zoning... maybe persistant binding methods... LOL!
Hopefully Doug can chime in here... He mentioned before about having experience with crank pulley replacement on the Rangers....
Hopefully Doug can chime in here... He mentioned before about having experience with crank pulley replacement on the Rangers....
#16
[quote=scrming,January 12, 2006, 4:18 AM]
Ok... now you guys are starting to scare me! All this physics talk... Can't week talk about World Wide Numbers and 4 Gigabit Fabric and soft zoning... maybe persistant binding methods... LOL!
Scrming youhave got to be kidding me, you are the master of taking it to the edge.I don't think anybody who regulary posts here has thrashed their car anymore than you have LOL, you have been my insperation... :worship: So for the record,just about any modification done to an otherwise stock engine has a degree of risk associated with it. That comes with the territory. Some folks seem to think that because an article was written about a BMW engine it directly applies to our 4.0. That may not be the case at all. We can find articles saying that running NOS or ZEX for that matter is bad, how about turbos,or superchargers? Just about any mod you make can and has broke something at one time or another. Tell you the truth crank failure is not one of the things I am worried about with this product ,as I have Doug's UDP on my car right now and have been driving the Heck out of it; no, the thing I am concerned about is the inertia ring seperating from the hub. That in my opinion is the ONLY real concern we should have with this product. If that happens you guys will know about right after I do. But for now I have the benefit of faster acceleration, more HP and Tq and a few more miles to the gallon. In fact I'm going to ask Doug if we can leave the UDP on my car and I'll pay him for it. And in the end if the thing goes to pieces, quess what.....I'll fix it and go after some more HP because thats what we do....we love it.... so it goes fellow Hot Rodders. I'll stop my rant now and silence the voice from the old school.
Ok... now you guys are starting to scare me! All this physics talk... Can't week talk about World Wide Numbers and 4 Gigabit Fabric and soft zoning... maybe persistant binding methods... LOL!
Scrming youhave got to be kidding me, you are the master of taking it to the edge.I don't think anybody who regulary posts here has thrashed their car anymore than you have LOL, you have been my insperation... :worship: So for the record,just about any modification done to an otherwise stock engine has a degree of risk associated with it. That comes with the territory. Some folks seem to think that because an article was written about a BMW engine it directly applies to our 4.0. That may not be the case at all. We can find articles saying that running NOS or ZEX for that matter is bad, how about turbos,or superchargers? Just about any mod you make can and has broke something at one time or another. Tell you the truth crank failure is not one of the things I am worried about with this product ,as I have Doug's UDP on my car right now and have been driving the Heck out of it; no, the thing I am concerned about is the inertia ring seperating from the hub. That in my opinion is the ONLY real concern we should have with this product. If that happens you guys will know about right after I do. But for now I have the benefit of faster acceleration, more HP and Tq and a few more miles to the gallon. In fact I'm going to ask Doug if we can leave the UDP on my car and I'll pay him for it. And in the end if the thing goes to pieces, quess what.....I'll fix it and go after some more HP because thats what we do....we love it.... so it goes fellow Hot Rodders. I'll stop my rant now and silence the voice from the old school.
![Big Grin](https://themustangsource.com/forums/images/smilies/biggrin.gif)
#17
[quote=05V6,January 12, 2006, 8:24 PM]
Thanks for your encouragement!!!
Originally Posted by scrming,January 12, 2006, 4:18 AM
Ok... now you guys are starting to scare me! All this physics talk... Can't week talk about World Wide Numbers and 4 Gigabit Fabric and soft zoning... maybe persistant binding methods... LOL!
Scrming youhave got to be kidding me, you are the master of taking it to the edge.I don't think anybody who regulary posts here has thrashed their car anymore than you have LOL, you have been my insperation... :worship: So for the record,just about any modification done to an otherwise stock engine has a degree of risk associated with it. That comes with the territory. Some folks seem to think that because an article was written about a BMW engine it directly applies to our 4.0. That may not be the case at all. We can find articles saying that running NOS or ZEX for that matter is bad, how about turbos,or superchargers? Just about any mod you make can and has broke something at one time or another. Tell you the truth crank failure is not one of the things I am worried about with this product ,as I have Doug's UDP on my car right now and have been driving the Heck out of it; no, the thing I am concerned about is the inertia ring seperating from the hub. That in my opinion is the ONLY real concern we should have with this product. If that happens you guys will know about right after I do. But for now I have the benefit of faster acceleration, more HP and Tq and a few more miles to the gallon. In fact I'm going to ask Doug if we can leave the UDP on my car and I'll pay him for it. And in the end if the thing goes to pieces, quess what.....I'll fix it and go after some more HP because thats what we do....we love it.... so it goes fellow Hot Rodders. I'll stop my rant now and silence the voice from the old school.![Big Grin](https://themustangsource.com/forums/images/smilies/biggrin.gif)
Scrming youhave got to be kidding me, you are the master of taking it to the edge.I don't think anybody who regulary posts here has thrashed their car anymore than you have LOL, you have been my insperation... :worship: So for the record,just about any modification done to an otherwise stock engine has a degree of risk associated with it. That comes with the territory. Some folks seem to think that because an article was written about a BMW engine it directly applies to our 4.0. That may not be the case at all. We can find articles saying that running NOS or ZEX for that matter is bad, how about turbos,or superchargers? Just about any mod you make can and has broke something at one time or another. Tell you the truth crank failure is not one of the things I am worried about with this product ,as I have Doug's UDP on my car right now and have been driving the Heck out of it; no, the thing I am concerned about is the inertia ring seperating from the hub. That in my opinion is the ONLY real concern we should have with this product. If that happens you guys will know about right after I do. But for now I have the benefit of faster acceleration, more HP and Tq and a few more miles to the gallon. In fact I'm going to ask Doug if we can leave the UDP on my car and I'll pay him for it. And in the end if the thing goes to pieces, quess what.....I'll fix it and go after some more HP because thats what we do....we love it.... so it goes fellow Hot Rodders. I'll stop my rant now and silence the voice from the old school.
![Big Grin](https://themustangsource.com/forums/images/smilies/biggrin.gif)
Thanks for your encouragement!!!
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