Underdrive Pulley's
11-28-2008, 11:13 PM
#1
I'm lost..
Thread Starter
Underdrive Pulley's
So until a couple weeks ago, I didn't know what an underdrive pulley was. It's not a mod that I've heard nearly as often as CAI, SC, ATLP exhaust etc.
I'm told it increases, or free's up 6-8HP. Noticeable difference IMO. My question is, why don't more people get this mod done?
This will definitely be the next mod for the car.
I'm told it increases, or free's up 6-8HP. Noticeable difference IMO. My question is, why don't more people get this mod done?
This will definitely be the next mod for the car.
11-28-2008, 11:59 PM
#3
TL-S izdashiznittt in
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Well if you notice people that have a CAI and exhaust, most likely have a UR pulley. Mines sitting in my room untill I get my ass up to install it.
Cant really say why more people dont have this mod but it is a good mod to have.
Cant really say why more people dont have this mod but it is a good mod to have.
Last edited by TLType-s12; 11-29-2008 at 12:02 AM.
11-29-2008, 01:18 AM
#5
I'm lost..
Thread Starter
yes it does because now it's working that much harder to drive the heater when you're plowing down the Hendai when its -30 in the winter :P
joking aside I'd be interested to know if this is correct or not as well.
11-29-2008, 01:23 AM
#6
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any light weight pulley i.e. unorthodox racing, will have a huge impact on your cars performance. A positive one.
Shedding a pound off of the crank is the equivalent of stripping 15 pounds off your car some where else...I don't remember what the UR crank pulley weighs but I';m sure you can do the math.
Its not a harmful mod, however it'll probably kill your gas mileage as you won't be able to keep you foot off the gas pedal.
Shedding a pound off of the crank is the equivalent of stripping 15 pounds off your car some where else...I don't remember what the UR crank pulley weighs but I';m sure you can do the math.
Its not a harmful mod, however it'll probably kill your gas mileage as you won't be able to keep you foot off the gas pedal.
11-29-2008, 06:26 AM
#7
why not?
because many people want a mod that makes noise- or can be seen.
others prefer ~stealth~
As an example of weight: the gen2 stock pulley is 8 pounds!!
the UR pulley is 1.8 pounds
do the math on how fast that gets the revs up, and you will see what fun it is to have.
Ziners who have installed one said- why did I wait to do this!!!
because many people want a mod that makes noise- or can be seen.
others prefer ~stealth~
As an example of weight: the gen2 stock pulley is 8 pounds!!
the UR pulley is 1.8 pounds
do the math on how fast that gets the revs up, and you will see what fun it is to have.
Ziners who have installed one said- why did I wait to do this!!!
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11-29-2008, 07:10 AM
#8
Registered Member
I installed an under drive pulley from Unorthodox Racing on my 2002 Altima SE. The dyno'd difference was 6.5 HP and 3 lb/ft of torque as I recall. It was only very slightly noticeable in first and second gear and I emphasize slightly.
Now the negatives. They tend to cause your belt to squeak, though this may not be a problem with the TL since it uses a tensioner. The real concern is if the stock pulley serves as a harmonic balancer, you DO NOT want to install a UDP. Do your research here and more than just a casual scan of the web. Also, I think the crank bolt on the TL requires 180 lb/ft when tightening it. This means removal and re-install is going to be a bit--. My Altima was 140 lb/ft and that was a bit of a bear.
Now the negatives. They tend to cause your belt to squeak, though this may not be a problem with the TL since it uses a tensioner. The real concern is if the stock pulley serves as a harmonic balancer, you DO NOT want to install a UDP. Do your research here and more than just a casual scan of the web. Also, I think the crank bolt on the TL requires 180 lb/ft when tightening it. This means removal and re-install is going to be a bit--. My Altima was 140 lb/ft and that was a bit of a bear.
11-29-2008, 08:17 AM
#9
Jokerman
I installed an under drive pulley from Unorthodox Racing on my 2002 Altima SE. The dyno'd difference was 6.5 HP and 3 lb/ft of torque as I recall. It was only very slightly noticeable in first and second gear and I emphasize slightly.
Now the negatives. They tend to cause your belt to squeak, though this may not be a problem with the TL since it uses a tensioner. The real concern is if the stock pulley serves as a harmonic balancer, you DO NOT want to install a UDP. Do your research here and more than just a casual scan of the web. Also, I think the crank bolt on the TL requires 180 lb/ft when tightening it. This means removal and re-install is going to be a bit--. My Altima was 140 lb/ft and that was a bit of a bear.
Now the negatives. They tend to cause your belt to squeak, though this may not be a problem with the TL since it uses a tensioner. The real concern is if the stock pulley serves as a harmonic balancer, you DO NOT want to install a UDP. Do your research here and more than just a casual scan of the web. Also, I think the crank bolt on the TL requires 180 lb/ft when tightening it. This means removal and re-install is going to be a bit--. My Altima was 140 lb/ft and that was a bit of a bear.
11-29-2008, 09:35 AM
#10
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3G Stock pulley = ~8 lbs
UR Pulley = ~1.5 lbs. (Tom says 1.8, so I'll just round it off a bit).
~ 6 - 6.5 pounds gained.
All I've read is that our crank pulley is NOT a harmonic balancer.
I've wondered though if it acts as a harmonic damper - this is a very different thing. A damper would absorb unwanted engine vibration that is transmitted through the crank shaft. *If* our pulley is harmonic damper, those unwanted vibrations would have to be absorbed by the engine which *could* lead to additional wear.
Realistically, I don't see this as a problem for a daily driver. A race car/track car, maybe, but not a run-of-the-mill 4-door sedan.
Get a new Gates Belt to minimize the liklihood of belt squeal.
If the car is pretty well modded, it's probably got a pulley. Remember: I/H/E are first order WHP mods, then come the misc goodies - like a pulley.
UR Pulley = ~1.5 lbs. (Tom says 1.8, so I'll just round it off a bit).
~ 6 - 6.5 pounds gained.
All I've read is that our crank pulley is NOT a harmonic balancer.
I've wondered though if it acts as a harmonic damper - this is a very different thing. A damper would absorb unwanted engine vibration that is transmitted through the crank shaft. *If* our pulley is harmonic damper, those unwanted vibrations would have to be absorbed by the engine which *could* lead to additional wear.
Realistically, I don't see this as a problem for a daily driver. A race car/track car, maybe, but not a run-of-the-mill 4-door sedan.
Get a new Gates Belt to minimize the liklihood of belt squeal.
If the car is pretty well modded, it's probably got a pulley. Remember: I/H/E are first order WHP mods, then come the misc goodies - like a pulley.
11-29-2008, 09:54 AM
#11
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Realistically, I don't see this as a problem for a daily driver. A race car/track car, maybe, but not a run-of-the-mill 4-door sedan.
care to explain why? is this in terms of a dedicated track car? i'm going to be taking th TL to the track a few times, and your statement makes no sense as to why it might be bad.
If the car is pretty well modded, it's probably got a pulley. Remember: I/H/E are first order WHP mods, then come the misc goodies - like a pulley.
GL finding a header for our car :P i've heard some things that some are in progress, but it won't happen anytime soon
11-29-2008, 10:01 AM
#12
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I mean a car that is run at high revs on a prolonged basis, repeatedly over an extended period of time - like a dedicated track car. Seems to me that if a some unwanted vibration exists it will wear on the engine more in extreme use than in "normal" use.
I don't think an occasional track event or occasional high RPM will matter in the long run. My *hypothosis* is that a small/normal amount of undamped vibration (*if* it exists; and I don't know whether it does or not) wouldn't show up as damage for a very long time, if ever.
I understand about headers. Perhaps you've heard of the Pre-Cat deletes and J-Pipe options? In our case these are the "substitute" mods for actual headers.
My point was the general mantra for more HP is I/H/E mods first.
Last edited by Bearcat94; 11-29-2008 at 10:03 AM.
11-29-2008, 10:16 AM
#13
Registered Member
3G Stock pulley = ~8 lbs
UR Pulley = ~1.5 lbs. (Tom says 1.8, so I'll just round it off a bit).
~ 6 - 6.5 pounds gained.
All I've read is that our crank pulley is NOT a harmonic balancer.
I've wondered though if it acts as a harmonic damper - this is a very different thing. A damper would absorb unwanted engine vibration that is transmitted through the crank shaft. *If* our pulley is harmonic damper, those unwanted vibrations would have to be absorbed by the engine which *could* lead to additional wear.
Realistically, I don't see this as a problem for a daily driver. A race car/track car, maybe, but not a run-of-the-mill 4-door sedan.
Get a new Gates Belt to minimize the liklihood of belt squeal.
If the car is pretty well modded, it's probably got a pulley. Remember: I/H/E are first order WHP mods, then come the misc goodies - like a pulley.
UR Pulley = ~1.5 lbs. (Tom says 1.8, so I'll just round it off a bit).
~ 6 - 6.5 pounds gained.
All I've read is that our crank pulley is NOT a harmonic balancer.
I've wondered though if it acts as a harmonic damper - this is a very different thing. A damper would absorb unwanted engine vibration that is transmitted through the crank shaft. *If* our pulley is harmonic damper, those unwanted vibrations would have to be absorbed by the engine which *could* lead to additional wear.
Realistically, I don't see this as a problem for a daily driver. A race car/track car, maybe, but not a run-of-the-mill 4-door sedan.
Get a new Gates Belt to minimize the liklihood of belt squeal.
If the car is pretty well modded, it's probably got a pulley. Remember: I/H/E are first order WHP mods, then come the misc goodies - like a pulley.
11-29-2008, 10:22 AM
#14
Registered Member
Just for clarification, the TL does use a belt tensioner, i know for a fact because i just had mine replaced. The harmonic balancer part has been beaten up numerous times here. Our pully does not act as a harmonic balancer, our engines are internally balanced (there one more time), this was told to me personally by an Acura Tech one night in conversation. You are right though about the 180 lb/ft for torque and this does cause a bit of hassel when and if you do it yourself. There are numerous threads on this site that explain how to change out the pully by yourself if you want to do it.
Lastly, make sure you use quality tools (as in ratchets and sockets) because you don't want to break a socket or ratchet connection when exerting that kind of force. Could be very bad on the hands.
11-29-2008, 10:27 AM
#15
Registered Member
I mean a car that is run at high revs on a prolonged basis, repeatedly over an extended period of time - like a dedicated track car. Seems to me that if a some unwanted vibration exists it will wear on the engine more in extreme use than in "normal" use.
I don't think an occasional track event or occasional high RPM will matter in the long run. My *hypothosis* is that a small/normal amount of undamped vibration (*if* it exists; and I don't know whether it does or not) wouldn't show up as damage for a very long time, if ever.
I understand about headers. Perhaps you've heard of the Pre-Cat deletes and J-Pipe options? In our case these are the "substitute" mods for actual headers.
My point was the general mantra for more HP is I/H/E mods first.
I don't think an occasional track event or occasional high RPM will matter in the long run. My *hypothosis* is that a small/normal amount of undamped vibration (*if* it exists; and I don't know whether it does or not) wouldn't show up as damage for a very long time, if ever.
I understand about headers. Perhaps you've heard of the Pre-Cat deletes and J-Pipe options? In our case these are the "substitute" mods for actual headers.
My point was the general mantra for more HP is I/H/E mods first.
11-29-2008, 12:09 PM
#17
Gates brand belts have been around forever and MUST be used with the UR pulley!
It has a different edge shape that matches the shape of the new pulley- got nothing to do with the tensioner- its about how the belt fits in the pulley groove and why they make noise
As for damage to the engine--not a problem. CL owners have been on this mod for years, and its popular with Gen2 TL crowd as well
On weight: I stated the shipping weight with box- to be safe in what I claimed as weight.
iirc its 1.6 lbs for the pulley itself
On removal:- kragen/partsamerica sells a $20 tool (order online) that holds the stock pulley still- so you can easily remove the main bolt. Otherwise its a strong breaker bar against the ground and hit the starter a few short taps- it works and doesnt hurt anything
To install: there is an access plate to the flywheel- and just like ANY automatic I have ever seen, jam a prybar into the teeth and the engine wont turn!
If no 200 lbs torque wrench in the toolbox at home, there are directions to get torque to 60 or 80 iirc, and then x degrees of rotation past that point. Its easy- with the proper tools
A shop that knows the job can do it in 20 minutes with ease.
Most will charge 30-45 minutes for the whole job- well worth it if you dont own the right tools and have a strong friend willing to work under the car.
Our sponsoring vendor Excelerate has the UR brand pulley and probably the right belt too
Give him a call or PM for azine price
It has a different edge shape that matches the shape of the new pulley- got nothing to do with the tensioner- its about how the belt fits in the pulley groove and why they make noise
As for damage to the engine--not a problem. CL owners have been on this mod for years, and its popular with Gen2 TL crowd as well
On weight: I stated the shipping weight with box- to be safe in what I claimed as weight.
iirc its 1.6 lbs for the pulley itself
On removal:- kragen/partsamerica sells a $20 tool (order online) that holds the stock pulley still- so you can easily remove the main bolt. Otherwise its a strong breaker bar against the ground and hit the starter a few short taps- it works and doesnt hurt anything
To install: there is an access plate to the flywheel- and just like ANY automatic I have ever seen, jam a prybar into the teeth and the engine wont turn!
If no 200 lbs torque wrench in the toolbox at home, there are directions to get torque to 60 or 80 iirc, and then x degrees of rotation past that point. Its easy- with the proper tools
A shop that knows the job can do it in 20 minutes with ease.
Most will charge 30-45 minutes for the whole job- well worth it if you dont own the right tools and have a strong friend willing to work under the car.
Our sponsoring vendor Excelerate has the UR brand pulley and probably the right belt too
Give him a call or PM for azine price
11-29-2008, 12:19 PM
#18
My TL can do this, too!
Did UR make a new pulley design? I have a stock diameter UR pulley. I took it into the grocery store one day and weighed it on the potato scale. It weighed 600g (1.3 lb).
The grocer gave me a WTF look. ha ha...
The grocer gave me a WTF look. ha ha...
11-29-2008, 12:41 PM
#19
Turd Polisher
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You went to a grocery store to weigh your pulley? 
Nice
.
Pulley ftw!
Nice
.Pulley ftw!
11-29-2008, 07:28 PM
#21
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For the record: I've got the Stock Sized UR Pulley installed.
I am not trying to scare anyone off this mod; I just think *every* mod has potential consequences and you should weigh Risk v Reward. I decided the risk was small compared to the reward.
Pulley is a great mod - car revs faster; got to go easier on the throttle or break traction. DIY was easy - Pulley tool, 4' breaker bar, muscle: voila, fini.
I am not trying to scare anyone off this mod; I just think *every* mod has potential consequences and you should weigh Risk v Reward. I decided the risk was small compared to the reward.
Pulley is a great mod - car revs faster; got to go easier on the throttle or break traction. DIY was easy - Pulley tool, 4' breaker bar, muscle: voila, fini.
11-29-2008, 07:54 PM
#22
they were making a stock size lightweight, and an underdrive pulley
There may be error between writers and the scale at the store
If you used the scale at the register- thats accurate,
but the ones in veggie aisle is just for close enough~
I heard they (UR) were not going to make the stock size anymore- just underdrive
which is fine as long as you keep the stereo below 600 amps
Check with Excelerate on that info- he is the man, and his shop is fairly close to URs
There may be error between writers and the scale at the store
If you used the scale at the register- thats accurate,
but the ones in veggie aisle is just for close enough~
I heard they (UR) were not going to make the stock size anymore- just underdrive
which is fine as long as you keep the stereo below 600 amps
Check with Excelerate on that info- he is the man, and his shop is fairly close to URs
11-29-2008, 07:54 PM
#23
Three Wheelin'
I have a TL and a CL with a combined mileage of 370,000 miles, yes you read that right. Of that, 270,000 miles has been with a UR crank pulley on both cars. No harmful effects what so ever. Both motors run perfectly.
11-30-2008, 08:50 AM
#24
Gates brand belts have been around forever and MUST be used with the UR pulley!
It has a different edge shape that matches the shape of the new pulley- got nothing to do with the tensioner- its about how the belt fits in the pulley groove and why they make noise
As for damage to the engine--not a problem. CL owners have been on this mod for years, and its popular with Gen2 TL crowd as well
On weight: I stated the shipping weight with box- to be safe in what I claimed as weight.
iirc its 1.6 lbs for the pulley itself
On removal:- kragen/partsamerica sells a $20 tool (order online) that holds the stock pulley still- so you can easily remove the main bolt. Otherwise its a strong breaker bar against the ground and hit the starter a few short taps- it works and doesnt hurt anything
To install: there is an access plate to the flywheel- and just like ANY automatic I have ever seen, jam a prybar into the teeth and the engine wont turn!
If no 200 lbs torque wrench in the toolbox at home, there are directions to get torque to 60 or 80 iirc, and then x degrees of rotation past that point. Its easy- with the proper tools
A shop that knows the job can do it in 20 minutes with ease.
Most will charge 30-45 minutes for the whole job- well worth it if you dont own the right tools and have a strong friend willing to work under the car.
Our sponsoring vendor Excelerate has the UR brand pulley and probably the right belt too
Give him a call or PM for azine price
It has a different edge shape that matches the shape of the new pulley- got nothing to do with the tensioner- its about how the belt fits in the pulley groove and why they make noise
As for damage to the engine--not a problem. CL owners have been on this mod for years, and its popular with Gen2 TL crowd as well
On weight: I stated the shipping weight with box- to be safe in what I claimed as weight.
iirc its 1.6 lbs for the pulley itself
On removal:- kragen/partsamerica sells a $20 tool (order online) that holds the stock pulley still- so you can easily remove the main bolt. Otherwise its a strong breaker bar against the ground and hit the starter a few short taps- it works and doesnt hurt anything
To install: there is an access plate to the flywheel- and just like ANY automatic I have ever seen, jam a prybar into the teeth and the engine wont turn!
If no 200 lbs torque wrench in the toolbox at home, there are directions to get torque to 60 or 80 iirc, and then x degrees of rotation past that point. Its easy- with the proper tools
A shop that knows the job can do it in 20 minutes with ease.
Most will charge 30-45 minutes for the whole job- well worth it if you dont own the right tools and have a strong friend willing to work under the car.
Our sponsoring vendor Excelerate has the UR brand pulley and probably the right belt too
Give him a call or PM for azine price
I guess what I am saying is....it depends on if you are NA or supercharged.
Last edited by MichaelBenz; 11-30-2008 at 08:53 AM.
11-30-2008, 09:45 AM
#25
ok you got me on that one- we were discussing a normal TL and for them- and you can verify this with the company or with Josh/Excelerate
Want no noise?- run the GATES belt
S/C cars of course will run whatever fits the S/C pulley on their car
For the normal car what I stated is correct info direct from maker and vendor
I dont make this stuff up people!
Want no noise?- run the GATES belt
S/C cars of course will run whatever fits the S/C pulley on their car
For the normal car what I stated is correct info direct from maker and vendor
I dont make this stuff up people!
11-30-2008, 09:53 AM
#26
ok you got me on that one- we were discussing a normal TL and for them- and you can verify this with the company or with Josh/Excelerate
Want no noise?- run the GATES belt
S/C cars of course will run whatever fits the S/C pulley on their car
For the normal car what I stated is correct info direct from maker and vendor
I dont make this stuff up people!
Want no noise?- run the GATES belt
S/C cars of course will run whatever fits the S/C pulley on their car
For the normal car what I stated is correct info direct from maker and vendor
I dont make this stuff up people!
Gates (or napa) on NA (napa's house brand is a gates belt last time I got one)
Goodyear Gatorback on Supercharged
11-30-2008, 10:00 AM
#28
Man of God.....
I bought the Pulley tool when I did this mod. I didn't even use it. The first person that pm's me gets it for what I paid. Never been used.
PS: I love this mod!
PS: I love this mod!
11-30-2008, 05:38 PM
#29
My TL can do this, too!
This pulley I weighed at the grocery store was done on a mechanical spring scale. It was zeroed out before I placed the pulley on to weigh it. I'm sure one could inquire the UR company and just ask them for their specs...
I weighed my stock pulley the other day on another store's digital grocery scale. That thing was 7.89 lb!
I weighed my stock pulley the other day on another store's digital grocery scale. That thing was 7.89 lb!
11-30-2008, 08:31 PM
#30
practicing nihilist
This is a valid concern. The Altima I had, had a damper.. I am certain. Harmonic dampers are almost always identified by a thin piece of non-metallic material sandwiched between the pulley section and the base. Harmonic balancers, on the other hand, serve a different purpose in life.
12-01-2008, 11:27 AM
#33
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12-01-2008, 12:08 PM
#34
12-01-2008, 08:39 PM
#35
Please search on this topic. The stock pulley is not a harmonic balancer. The stock pulley has a rubber ring (elastomer) to reduce noise in the engine bay. It does not have the ability to balance out vibrations from the engine, which is why the engine is internally balanced.
The stock pulley is just under 8 lbs and the UR underdrive pulley is 15 ounces. The stock diameter UR pulley is 1 lb.
The stock pulley is just under 8 lbs and the UR underdrive pulley is 15 ounces. The stock diameter UR pulley is 1 lb.
12-04-2008, 06:01 AM
#36
I'm lost..
Thread Starter
Just bought the pulley & belt and had it installed. takes a few days for it to really kick in, but I'm already noticing better acceleration and im on day 2 
12-05-2008, 10:31 AM
#37
Suzuka Master
iTrader: (2)
Explain what the ECU is going to alter over a few days time to increase the car's output......lol.
12-05-2008, 02:45 PM
#40
practicing nihilist
I don't know, man. A lot of people say they really feel the car wake up a couple days after install. I agree that it should be an instantaneous mod...just shedding weight.