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etec-II underdrive pulley development
NOTE: the official group buy thread for this pulley is here:
E-TEC II underdrive pulley group buy - Chevrolet Aveo forum and owners club - AveoForum.com
Post in that thread if you're interested in one.
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I'm starting a new thread on this to separate it from other discussion that had been going on. I know there is a lightweight pulley available from Xaiogary, but the price is a bit high and I think we can do better if we do a group buy on the board here.
Anyway, I have actually been thinking about this for a while. An underdrive crankshaft pulley is a very simple mod that is usually pretty low cost. It works not only by being lighter in weight than the original pulley (less rotational mass like a lightweight flywheel), but also by being smaller in diameter. This in turn spins your accessories slower which frees up some horsepower as well.
I'd love to get input and know if people are interested. If all goes well we can put together a group buy. The more people we get the cheaper the parts get, thats the way things work. So, let me know if you are interested.
People interested:
Daox
reddemonx92
serega12
one_man_jam
thehunterooo
xintersecty
AveoSS
theclarkfam???
petrified.rabbit???
bdc87???
I'm also still interested in knowing how the ecotec pulley compares to the etec. If anyone could even get a picture of the ecotec pulley we could probably know right there if it won't work.
So, I have modeled up the stock pulley at this point. I figured I'd share some pretty pictures with you guys (we all like pics after all). :)
http://aveoclub.net/pictures/pulley01.jpg
http://aveoclub.net/pictures/pulley02.jpg
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Re: etec underdrive pulley development
I wouldnt mind buying it if it was reasonably priced and increased hp even if its just a few.
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Re: etec underdrive pulley development
I have heard about this long before I was looking at the aveo and it intrigued me then and I was hoping to see something about it for these cars.
Here are a couple things that I found on the underdrive pulley. there is a lot of information out there about this subject below is a few links to other forums.
The questions that I have is what size pulley will be needed to make it work, what would the cost be and would all the accessories still work correctly at the lower RPM's?
http://www.aeriostyle.com/forum/viewtop ... 8&start=45
http://clubaleno.21.forumer.com/a/j18-u ... ost66.html
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Re: etec underdrive pulley development
Quote:
Originally Posted by theclarkfam
The questions that I have is what size pulley will be needed to make it work, what would the cost be and would all the accessories still work correctly at the lower RPM's?
I'd be happy to answer your questions theclarkfam.
I am unsure of the pulley that will be needed. I have simply redrawn the stock pulley at this point. From there, I'll modify it.
The cost is completely dependant on how many people are interested. The more people, the lower the cost. I will be submitting my drawing for quotes to a few different shops to get a good price of course.
I mentioned this in the other thread I had linked, but the accessories (besides the alternator) won't really make any difference operating at a lower rpm. If you time it, your A/C probably won't get cold quite as fast (we're talking a few seconds), and you won't have as much power steering assist. From my experience using underdrive pulleys on different cars, you'll never even notice the difference. I surely didn't, but could notice the extra power. Its not a ton, but its noticable. Similar to a cold air intake I'dsay. The one thing we do need to look out for is the alternator. If we spin it too slow, it won't be able to produce enough voltage to charge the battery at idle. This would be bad. So, this will be part of the design process to ensure that this does not happen. On other vehicles, you can easily underdrive the crankshaft by 15-20% without any problems. We just have to see how much overhead there is in the Aveo to play around. This will be very easy to do considering I have my alternator out of the car right now, I can simply do some bench testing to see at what rpm the voltage starts to fall. From there, I can size the pulley accordingly.
I will be going through the whole design process on the board. If anyone has any questions, please feel free to ask.
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Re: etec underdrive pulley development
Thanks for answering that and I can't wait to see the finished product.
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Re: etec underdrive pulley development
So, Daox, just to paraphrase what you said, you're trying to design a pulley that will still allow the alternator to give us enough voltage/amperage (whatever else is needed) to charge our battery at the lowest RPM possible while still giving us enough power gain to be noticeable. If that's correct, and the price is reasonable, I would be interested in one. Could you post up some quotes when you receive them to see what we're looking at? I'm sure having a price in here would make it easier for people to see if it's something they're willing to invest in.
By the way, good idea with a group buy.
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Re: etec underdrive pulley development
Yeah that pretty much sums it up. I have most everything done besides sizing the pulley to the alternator. I do have a rough idea of what it'll be, but I want to test it out before finalizing anything.
I will definitely post the quotes when I get them back. But, I need a final drawing before I request them. If we only have 4 people interested its gonna be expensive unfortunately.
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Re: etec underdrive pulley development
count me in. any improvement, even subtle, sounds like a worthwhile upgrade :D
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Re: etec underdrive pulley development
i just went through looking at pictures of the ecotec versus the etecII, im 99% sure its different, especially in design it appears to have a rubber dampening ring?(just from looking at pictures online not looking at mine) that last 1% is the different design does not mean not interchangeable.. because the mounting point / offset etc might be the same.
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Re: etec underdrive pulley development
Everyone has a different idea of expensive... if it was under 100 - I'm sure many people wouldn't mind getting 3-4 HP at that price (if that's what we're looking at as far as power gain and price range).. if its 250$+ for a 1-2 HP not many people (including myself) will find it worth the money. :D could you post at least some rough numbers, or PM me?
Thanks ahead.
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Re: etec underdrive pulley development
Anyone know off hand what Xaiogary's cost? Might be a good reference point to post in this thread.
The machining quote is going to be the clincher.
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Re: etec underdrive pulley development
Quote:
Originally Posted by MetroMPG
Anyone know off hand what Xaiogary's cost? Might be a good reference point to post in this thread.
The machining quote is going to be the clincher.
The other thread I had a link to in the first post linked to a site that had one for $260. I'm not sure if you can get it elsewhere cheaper. IMO that is a really high price.
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Re: etec underdrive pulley development
Quote:
Originally Posted by serega12
Everyone has a different idea of expensive... if it was under 100 - I'm sure many people wouldn't mind getting 3-4 HP at that price (if that's what we're looking at as far as power gain and price range).. if its 250$+ for a 1-2 HP not many people (including myself) will find it worth the money. :D could you post at least some rough numbers, or PM me?
Thanks ahead.
I would hope we can get them for under $150. I'm designing the pulley to be as cheap as possible to make. As always, it depends on quantity mainly though.
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Re: etec underdrive pulley development
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Re: etec underdrive pulley development
No problem. Lets just hope I can hit that target! :)
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Re: etec underdrive pulley development
light weight pulley for aveo $160 plus shipping= http://www.motorexonline.com/crankpulleys.html
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Re: etec underdrive pulley development
Bam! =D>
If you're still going to get quotes, Tim, let me know. I have a friend who's a machinist - has his own shop. I'll ask him if you want.
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Re: etec underdrive pulley development
is that price current? i went through and found a us distributor.. but not going to pursue too far since it doesnt fit my car.
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Re: etec underdrive pulley development
Quote:
Originally Posted by dleebold
anyone have any experience with these folks? is 160 a good or reasonable price?
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Re: etec underdrive pulley development
Quote:
Originally Posted by dleebold
Thats not an underdrive pulley. You won't see as much of a gain from it.
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Re: etec underdrive pulley development
I did some more work on the pulley this weekend. But, I also weighed the stock pulley. It comes in at exactly 5.5 lbs. Currently, my pulley is right around 1lb. :)
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Re: etec underdrive pulley development
what software are you using?
depending on price i might buy on just to see if it fits.. but it would be better to try and oem one first.
i imagine the stock on one the ecotec is a little lighter based on the rubber looking insert. but maybe i will take it off for comparison (car is coming of the road next week for rebuild)
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Re: etec underdrive pulley development
I'm using SolidWorks to model the pulley.
Pulling your pulley off would be great to compare. Thanks!
You've probably seen these already, but here are the crankshaft pulley images I took while disassembling the engine. The timing belt section pulls right out of the larger pulley. I'll get some more pictures of it later.
http://aveoclub.net/pictures/aveo023.JPG
http://aveoclub.net/pictures/aveo024.JPG
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Re: etec underdrive pulley development
Well, the pulley is pretty much done. I just have one more thing to do, and thats verify the alternator will provide enough output at the new rpm.
http://aveoclub.net/pictures/pulley03.jpg
http://aveoclub.net/pictures/pulley04.jpg
I took some time today and ran a couple quick FEAs (finite element analysis) on the pulley to see if it will hold up to the stresses of use. This basically shows me the stress distribution through the pulley. Please note that the deformation of the pulley is for visual effects only, it will not actually deform. :) I also used very rough numbers for these calculations, so I erred on the conservative side to ensure a good pulley.
http://aveoclub.net/pictures/pulley05.jpg
http://aveoclub.net/pictures/pulley06.jpg
http://aveoclub.net/pictures/pulley07.jpg
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Re: etec underdrive pulley development
Underdrive pulleys designed by Salvador Dali. I like.
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Re: etec underdrive pulley development
This is coming along well. I can't believe the stocks only weighs 5.5lbs and this one is at 1lb. Can't wait to see it produced and how it effects the rpm's.
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Re: etec underdrive pulley development
So if I may ask what does the underdrive pulley do to the engine?
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Re: etec underdrive pulley development
Underdrive reduces the accessory load on the engine by lowering the accessory RPM. EG: a smaller (underdrive) crank pulley will cause the power steering pump and alternator to spin at a lower rate than stock, reducing drag on the engine.
This frees a small amount of additional power for acceleration. It also marginally reduces cruising power requirements, potentially increasing fuel economy (again, by a small amount).
For more info, wikipedia: http://en.wikipedia.org/wiki/Underdrive_pulleys
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Re: etec underdrive pulley development
If I can also add to the question above.
The feeling you get from a lightweight crank pulley is not from the hp it frees up but it's ability to spin faster thus pushing you through the rpm's faster. I don't know what it will feel like going from 5.5lbs down to 1lb but, my experience comes from going from a 15lb down to 4lb.
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Re: etec underdrive pulley development
Oh ok thanks for all the info guys. much appreciated. So will it give u like a half a gallon to a gallon more per mile? on the economic side of the pulley
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Re: etec underdrive pulley development
Quote:
Originally Posted by reddemonx92
Oh ok thanks for all the info guys. much appreciated. So will it give u like a half a gallon to a gallon more per mile? on the economic side of the pulley
In theory it should because of the reduce pull, however in real-world experience you might see it drop by 1-2mpg as you might tend to feed the pedal more and you'll want to. To counteract this you'll have press less on the accelerator to keep the rpm change the same as before but, what would be the point of the pulley?
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Re: etec underdrive pulley development
I've never seen anyone quantify any fuel economy gain from a pulley change. People do this for the acceleration/power, not generally to save gas. My guess is it probably wouldn't pay for itself over any reasonable amount of time (if that's your goal).
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Re: etec underdrive pulley development
Na i can pay gas that isnt a problem... i just want to get alittle more power outa my automatic tranny
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Re: etec underdrive pulley development
im in 10000000000% of any cheap parts you guys can make, ill buy anything
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Re: etec underdrive pulley development
So wut is gonna be the price of this when you guys finish developing it?
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Re: etec underdrive pulley development
should not be too much, maybe 150 or so, i will buy it anyways :D
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Re: etec underdrive pulley development
I think they said the price will depend on how many people will be getting it. More people = lower price.
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Re: etec underdrive pulley development
how many people do we have so far? Should have a list on the front page maybe
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Re: etec underdrive pulley development
Or maybe add a poll at the beginning of the thread (this one or a new one) with options like "yes", "no", and "considering" or something... just an idea. :D
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Re: etec underdrive pulley development
Quote:
Originally Posted by thehunterooo
how many people do we have so far? Should have a list on the front page maybe
Looks like 5 are interested. 3 more are semi-interested.
Updating the first page is a good idea.
If anyone else is interested and doesn't find their name below please let me know. This is by no means a commitment, its just so I get an idea of how many people are interested. The current list is:
Daox
reddemonx92
serega12
one_man_jam
thehunterooo
theclarkfam???
petrified.rabbit???
bdc87???