Under Drive Pullies
And Another Logical Reason To Get The Pullies Would Be Better Gas Mileage. For A 100 Bucks I Spent On The Pullies I Get About 40 More Miles A Tank Which If You Ask Me Will Recover The Cost Of The Pullie Pretty Quickly If You Drive As Much As I Do.
So Lesson Learned : 19 Year Olds Have Better Logic Than Anyone, Including Engineers.
So Lesson Learned : 19 Year Olds Have Better Logic Than Anyone, Including Engineers.
If this is real long term dopcumented I susspect he inadvertantly fixed some problem in the course of the mod. Maybe some little thing like a loose intake plumbing that got put back togheter better or the like.
I have a co-worker who swears he get 2mpg better with one of those Tornado things
, so sometimes people just experiance something positive when it is not there too.The UD pulley tecnically does allow the engine to do less work turning the PS and AC but not so much less as to cause a significant milage gain like that. If a gain that substantial was possible GM would have done it from the factory with a smaller drive because CAFE means every tiny fraction of a MPG matters to manufacturers.
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Banned
Joined: Oct 2007
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well if it makes any difference this is freeway driving that i can tell the difference on. it is adevertised that the pullies will give 2-3 MPG better. now how true that is i am unsure as i have no solid proof other than my car. the onyl changes that happened while the pullies were installed was the AIR/EGR being removed. other than that i did not have any other things changed. and if i were to be getting 2 miles per gallon better that would amount to 30 miles on a tank. i said i was experiencing about 30-40 depending on how much i get on the throttle. but id say for 100 bucks its a great investment as it has many advantages that easily weight out the only disadvantage which would be you cant really have a system with them. and my car already weighs enough i dont need to add a 100 lbs of stereo equipment.
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From: Decatur, TN (N-W of Athens)
Been done, guys claim a real noticable gain from the reduced rotating weight but this will destroy bearings no matter how well the engine is balanced. The front end of an LT1 is internal balanced anyway but that device on an LT1 is a damper/pulley, on a 400 it is a balancer though we often call it a balancer on an LT1.
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Launching!
Joined: Nov 2007
Posts: 271
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From: Moore Oklahoma
Been done, guys claim a real noticable gain from the reduced rotating weight but this will destroy bearings no matter how well the engine is balanced. The front end of an LT1 is internal balanced anyway but that device on an LT1 is a damper/pulley, on a 400 it is a balancer though we often call it a balancer on an LT1.
WD
http://www.jegs.com/webapp/wcs/store...10002_80036_-1
I have pulled the belt at the track, gain about .1 only logical that you would at most gain whatever the UD is, which is at most 34%. Well 34% of .1 is .034seconds. If you OD the alternator that will reduce gains. If you up idle to compensate for charging issues that will be more fuel used idling eating into any potential MPG gains.
You are saying my argument is ignorant only because you decided before you read it I was going to be wrong.
A LOT of the times particularly with "educated" people they tend to overthink things and get lost in theory ignoring the real world.
I will say I am just a carpenter but working with my hands all day building things gives a better understanding of REALITY that a book and piece of paper ever could.
You are saying my argument is ignorant only because you decided before you read it I was going to be wrong.
A LOT of the times particularly with "educated" people they tend to overthink things and get lost in theory ignoring the real world.
I will say I am just a carpenter but working with my hands all day building things gives a better understanding of REALITY that a book and piece of paper ever could.
I have pulled the belt at the track, gain about .1 only logical that you would at most gain whatever the UD is, which is at most 34%. Well 34% of .1 is .034seconds. If you OD the alternator that will reduce gains. If you up idle to compensate for charging issues that will be more fuel used idling eating into any potential MPG gains.
You are saying my argument is ignorant only because you decided before you read it I was going to be wrong.
A LOT of the times particularly with "educated" people they tend to overthink things and get lost in theory ignoring the real world.
I will say I am just a carpenter but working with my hands all day building things gives a better understanding of REALITY that a book and piece of paper ever could.
You are saying my argument is ignorant only because you decided before you read it I was going to be wrong.
A LOT of the times particularly with "educated" people they tend to overthink things and get lost in theory ignoring the real world.
I will say I am just a carpenter but working with my hands all day building things gives a better understanding of REALITY that a book and piece of paper ever could.
Launching!
Joined: Nov 2007
Posts: 271
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From: Moore Oklahoma
I'm somewhat unique! I "can connect" theory and practical application together and prove my point! I race my LTX car just about every weekend in NHRA events, so I'm very much on-top-of it's performance. And, know exactly how it got to where it is in performance (I probably race much more than most people here on the forum).
Again, a few hundredths here, a tenth there and before long you’re going really fast. Basically, it is about squeezing-out and using every potential HP possible from your package. And, that is my point with the underdrive pulley issue.
Of course, if you choose "not" to take advantage of every bit of potential performance in your car, that is fine with me. But something to consider if you race me sometime.
WD
Again, a few hundredths here, a tenth there and before long you’re going really fast. Basically, it is about squeezing-out and using every potential HP possible from your package. And, that is my point with the underdrive pulley issue.
Of course, if you choose "not" to take advantage of every bit of potential performance in your car, that is fine with me. But something to consider if you race me sometime.
WD
i am not arguing people saying it is the best mod, but it is not a best bang for your buck. Now people are going to be going out ordering these pulleys and not see much IF any gain and be out over 100$. for the price of that they could spend just a little more and get rid of the stock tune with a mail order and gain alot more.
I think people mistake fast for done right. I see a huge number of cars that cost way too much for the ET they run.
Watched a 3855lbs Impala run 121.2 mph in 105F heat NA with ported GM heads. At a 1650ft DA it ran 10.80 at 124mph, too bad he did not get to run it in a negative fall DA.
Not high dollar built the 383 himself, as well as the 4L60E, rollbar and suspension work. Stock opti on the damned thing too, far as I am concerned that is a guy to listen too, there are cars faster but what he is getting out of it for what he has into it is what makes me say he is the one doing things right.
We all have budgets, well the vast majority of us, apply that budget carefully. Buying every last thing that might be worth .00x is not spending money well untill you have maxed out the bigger stuff. On a stock motor take that money and put it towards valvesprings, you will see more gain, granted only at high rpm but good springs and you get a few hundred more rpms out of a stock cam.
I have also heard of wear issues on some of the aluminums.
Like I said when I buy a damper it will be an UD, till then I wont bother and I might just do something fancy like the aluminum ATI, the rotating weight savings being an aditional benifit.
Watched a 3855lbs Impala run 121.2 mph in 105F heat NA with ported GM heads. At a 1650ft DA it ran 10.80 at 124mph, too bad he did not get to run it in a negative fall DA.
Not high dollar built the 383 himself, as well as the 4L60E, rollbar and suspension work. Stock opti on the damned thing too, far as I am concerned that is a guy to listen too, there are cars faster but what he is getting out of it for what he has into it is what makes me say he is the one doing things right.
We all have budgets, well the vast majority of us, apply that budget carefully. Buying every last thing that might be worth .00x is not spending money well untill you have maxed out the bigger stuff. On a stock motor take that money and put it towards valvesprings, you will see more gain, granted only at high rpm but good springs and you get a few hundred more rpms out of a stock cam.
I have also heard of wear issues on some of the aluminums.
Like I said when I buy a damper it will be an UD, till then I wont bother and I might just do something fancy like the aluminum ATI, the rotating weight savings being an aditional benifit.