Morning Repost: Lightweight Underdrive Pully Set on a 2.7t
12-13-2002, 05:17 AM
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Morning Repost: Lightweight Underdrive Pully Set on a 2.7t
would you put it on your S4?
why, or why not?
main question is simple... does the 2.7t use a balanced/dampened pulley or a harmonic balancer?
a few have said yes, but with no real data to back up the claim... yet.
I understand the 1.8 does use a balanced/dampened pully
Let's discuss the principles of balancing an engine.
I feel chipping the car, even though it reduces longevity, is worth the compromise. Many of you must feel the same way since many on these forums have chipped their cars...
many of us have done quite a bit which potentially decreases the reliablity/longevity of the car...
so what i'm asking for is this:
would an underdrive pully set cause serious problems in the short term, or in the long term?
I'm guessing it wouldn't starve the engine of oil, since it's run off the main pully/ratio...
and...
a lightened flywheel doesn't throw things off balance enough to ruin the crank/block in the relatively short run...
I'd really appreciate actual data if possible instead of random guesses. I've been making a lot of guesses myself on this... I'm turning to the forums and the head tech at my local dealership for some actual technical info i can refer to
why, or why not?
main question is simple... does the 2.7t use a balanced/dampened pulley or a harmonic balancer?
a few have said yes, but with no real data to back up the claim... yet.
I understand the 1.8 does use a balanced/dampened pully
Let's discuss the principles of balancing an engine.
I feel chipping the car, even though it reduces longevity, is worth the compromise. Many of you must feel the same way since many on these forums have chipped their cars...
many of us have done quite a bit which potentially decreases the reliablity/longevity of the car...
so what i'm asking for is this:
would an underdrive pully set cause serious problems in the short term, or in the long term?
I'm guessing it wouldn't starve the engine of oil, since it's run off the main pully/ratio...
and...
a lightened flywheel doesn't throw things off balance enough to ruin the crank/block in the relatively short run...
I'd really appreciate actual data if possible instead of random guesses. I've been making a lot of guesses myself on this... I'm turning to the forums and the head tech at my local dealership for some actual technical info i can refer to
12-13-2002, 06:04 AM
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I was told the autospeed pully is just a lighter pully, and is not actually smaller than the stock
crank pully.
if you're looking for people who are using it, I suggest calling Zev@avalonmotorsports.com
he may have sold a few so far.
however, the pully set i am considering is not from autospeed. the ones I am considering are not only reduced in weight, they are also approx 20% reduced in diameter.
if you're looking for people who are using it, I suggest calling Zev@avalonmotorsports.com
he may have sold a few so far.
however, the pully set i am considering is not from autospeed. the ones I am considering are not only reduced in weight, they are also approx 20% reduced in diameter.
12-13-2002, 06:09 AM
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you're exactly right on it being the same size. I thought reduced mass made the biggest difference?
Undersize added additional hp but i don't like the idea of undersizing. I do like the idea of reduced mass.
12-13-2002, 06:16 AM
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same size is probably the safest route.
underdriving may not bring about as much hp as you'd think. from reading info on many manufacturer's websites, it seems that although a smaller pully will add more since it underdrives more... they claim the real gains are from the lighter weight
i highly suggest you do your research though. whether you go with the same size pully or a smaller one... you'd have the same problems... that is, IF you would have problems... and that is exactly what i'm trying to find out for sure.
i highly suggest you do your research though. whether you go with the same size pully or a smaller one... you'd have the same problems... that is, IF you would have problems... and that is exactly what i'm trying to find out for sure.
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12-13-2002, 06:29 AM
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Mark and I made our own. I believe EVO and maybe SPP has a kit
I will tell you now that we had to remove the entire pulley assembly with the fan and make a timing belt cover for that area. We used a TFAL shallow fan and it still didn't clear the pulley. Oh well that pulley serves only for the fan. Also we had to get a shorter belt.