Underdrive pulleys
- Thread starter ktaylOR2012
- Start date
03_TrueBlue_GT
Active Member
Cant hurt to have I guess, I hear they help the motor rev up quicker, other than that I heard they dont add much hp. I would prob do it last like if I had TB, full exhaust, tune and an intake I would consider getting them...
They sound like a decent mod. Here's my thread from a few months back with some more info....
http://www.stangnet.com/mustang-forums/835709-pullies-101-a.html
http://www.stangnet.com/mustang-forums/835709-pullies-101-a.html
- Jul 21, 2005
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No no no no. I have seen dyno results where the entire accessory drive belt was removed from a bone stock mustang and guess what the gains were from running ZERO accessories???
A WHOPPING 2.2 hp.
Don't waste your money. I've installed them on multiple stangs of the v6 and v8 variety, a focus and another brand x car and can tell you the modular was the biggest pain. You have a dampener built into your crank pulley and it requires you to use a pulley puller and do it just right. For the time, money and hassle is maybe 2 Hp worth it?
Again, no.
A WHOPPING 2.2 hp.
Don't waste your money. I've installed them on multiple stangs of the v6 and v8 variety, a focus and another brand x car and can tell you the modular was the biggest pain. You have a dampener built into your crank pulley and it requires you to use a pulley puller and do it just right. For the time, money and hassle is maybe 2 Hp worth it?
Again, no.
I've gained a solid .1 at the track and a full 1mph on 2 of my 2v mustangs I've put them on. Underdrive pulleys don't add hp to your car. They free up hp by lessening parasitic loss.
- Jul 21, 2005
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Freed horsepower would be both represented by total gains and curves on the dyno, neither which were present.
You've just fallen victim of modding and driving on a different day and assuming it was mods. While both are consistent by your account, there are many more variables at play with your experience than with the tools I saw debunk the udp myth.
Not necessarily... have you ever run back to back dyno's with wheels that weigh different amounts? FWIW, the difference in RWHP numbers is negligible, yet the car with lighter wheels (assuming the same size and brand of tire) will likely perform better in the 1/4 mile.
- Jul 21, 2005
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But that is directly related to inertia and what I am referencing can be noticed on a dyno considering its operative is to "free horsepower"
No it is also inertia related... no different than wheels....
Besides you clearly don't know chit... I mean for the christs sake you have a centri (-10 knowledge points) on a stock 5.0 block (-20 knowledge points)... seriously man hurry up and grab a rag to mop up your drool you damn retard.
Besides you clearly don't know chit... I mean for the christs sake you have a centri (-10 knowledge points) on a stock 5.0 block (-20 knowledge points)... seriously man hurry up and grab a rag to mop up your drool you damn retard.
- Jul 21, 2005
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Back to the argument at hand, since we're two tards arguing, the measurement for less rotating mass of rolling stock is the 1/4. The measurement of less parasitic loss is measured on a dyno, and also a track. But dyno will not lie in the sense of a back to back dyno same day same time.
@ 2 tards *wipes chin* This isn't easy to explain but I'll try... dyno pulls are done in 3rd/4th gear in an effort to obtain an ideal 1:1 ratio (engine RPM and wheel RPM). The other component of this is rotating mass and the drive accessories have an impact on the speed in which an engine will rev. Under a heavy dyno load, rotating mass as well as parasytic loss doesn't play as big a part because you're working against the load on the dyno. However in 1st and 2nd gear the gears are short enough where the engine isn't being loaded as heavily as in 3rd and 4th gear... therefore the speed in which that engine is able to rev does play a role in 1/4 mile time. UDP's as well as light flywheels, light wheels, etc... allow the engine to rev at a more rapid pace yet may not be noticed on the dyno.
- Jul 21, 2005
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I can't argue that logic, but I would still argue for 200 there are better mods and it's negligible.
*puts on helmet*
Chit, we're not supposed to prove useful members.
*puts on helmet*
Chit, we're not supposed to prove useful members.
sneaky98gt
10 Year Member
But dyno will not lie in the sense of a back to back dyno same day same time.
I don't know that I entirely agree with that. IN MY OPINION, a dyno is a tuning tool, and not really a good tool for measuring power output. Trap speed at the track is a better measure of that.
For example, when I got a recent dyno tune, we did a pull with 18 degrees of timing, and got xxx horsepower/torque (don't remember the numbers now). Let it cool down, and 30 minutes later did another pull COMPLETELY identical other than that it was at 23 degrees of timing (I'm spraying methanol to run that much timing). The dyno showed NO gain whatsoever, at any point in the rpm range. It was literally identical across the board.
A piston disintegrated at the track before I got chance to test which ran better at the track. But I have a friend who REALLY knows these cars/blowers/methanol, and he said he'd put money on it that it would run a measurable amount faster at the track with the 23 degrees of timing, even though it showed no gains on the dyno.
I'll be getting back on the dyno again sometime next week, and after it gets tuned, I'm fully planning on testing that theory. So far, my friend has been spot-on about everything he's told me. So I guess we'll see.
And back on topic. The way I feel about it is that if Ford put them on the '01 Bullitts from the factory, they must feel there's some benefit to be had out of them.
My track times don't lie. Multiple cars of mine. I've probably got 10 times the seat time at the track as you do. I track the DA, wind, 60ft, shift points, 330', 1/8 ET and MPH compared to what the car back halfs, etc.
I'll say it again, pulleys are worth a solid tenth in the 1/4.
- Jul 21, 2005
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My track times don't lie. Multiple cars of mine. I've probably got 10 times the seat time at the track as you do. I track the DA, wind, 60ft, shift points, 330', 1/8 ET and MPH compared to what the car back halfs, etc.
I'll say it again, pulleys are worth a solid tenth in the 1/4.
Uh oh! E peen contest!
I gave my input, y'all sped your money how you want. I consider them a huge waste.
musclemustangcb
Member
- Nov 20, 2011
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musclemustangcb
Member
- Nov 20, 2011
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My track times don't lie. Multiple cars of mine. I've probably got 10 times the seat time at the track as you do. I track the DA, wind, 60ft, shift points, 330', 1/8 ET and MPH compared to what the car back halfs, etc.
I'll say it again, pulleys are worth a solid tenth in the 1/4.
Uh oh! E peen contest!
I gave my input, y'all sped your money how you want. I consider them a huge waste.
ruh roh...
opcorn:FIGHT... FIGHT...FIGHT...
03_TrueBlue_GT
Active Member
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