UDP Installed - My Thoughts
07-07-2002, 11:20 AM
#1
UDP Installed - My Experience
I finally installed the Underdrive Pulley I've had sitting in my tool chest for the last six months. 
Main Pulley Bolt
I used the "bleep the starter" method. Leveraged the arm of my 1/2" breaker bar against the control arm with a 19mm socket and "bleeped the starter" a couple times. The bolt loosened with no problems.
Idler Pulley Tensioner
Loosening the idler pulley for the main drive belt was cake. The bolt on the idler pulley itself took a little force with a crescent wrench. There isn't enough space to get a ratchet in there, or the removal would be much easier...but a little force will loosen it. The tensioner itself is easily accessible from the top of the engine bay with about nine inches of ratchet extension.
Power Steering Belt Tensioner
What an f'ing pain in the a$$. Take everything you heard about how hard it is to loosen the power steering belt tensioner and double it to set your expectations correctly. I'm sure that if I had to do it again, and I will, it would be significantly easier. The first time around, it was an enormous hassle. Thanks everybody who posted their experiences before...but it just couldn't accurately represent the giant nightmare that the power steering pump became. Have I explained this clearly?
New Belts
After sliding the new UDP on with some anti-seize grease on the inner-bore, I started picking from my large array of belts. In the end, I returned an original Nissan belt for the Power Steering Pump. I fully lowered the pump, as far as it would go, and there was still no way the smaller belt recommended in the UDP install was going to fit on. The original belt fits perfectly.
I used Gates K060410 for the larger belt. The recommended K060408 was just a bit too small and K060410 fit nicely.
140 ft/lbs. of Torque
To get the new pulley bolt tightened to 140 ft/lbs. of torque, I used the partner in the driver's seat method. Had somebody sit in the driver's seat, put it in 5th gear, and press the brake pedal for all they were worth. With this method, I easily used my torque wrench to torque up the bolt to 140 ft/lbs. Took very little effort and I was all done.
Results
In the end, there is no squeal or whine since I took care to tighten the belts up to recommended deflection. My first drive around town was for dinner and drinks last night. I didn't notice a great deal of difference, but I'll put the pulley to the test more aggressively in coming weeks I'm sure.
Main Pulley Bolt
I used the "bleep the starter" method. Leveraged the arm of my 1/2" breaker bar against the control arm with a 19mm socket and "bleeped the starter" a couple times. The bolt loosened with no problems.
Idler Pulley Tensioner
Loosening the idler pulley for the main drive belt was cake. The bolt on the idler pulley itself took a little force with a crescent wrench. There isn't enough space to get a ratchet in there, or the removal would be much easier...but a little force will loosen it. The tensioner itself is easily accessible from the top of the engine bay with about nine inches of ratchet extension.
Power Steering Belt Tensioner
What an f'ing pain in the a$$. Take everything you heard about how hard it is to loosen the power steering belt tensioner and double it to set your expectations correctly. I'm sure that if I had to do it again, and I will, it would be significantly easier. The first time around, it was an enormous hassle. Thanks everybody who posted their experiences before...but it just couldn't accurately represent the giant nightmare that the power steering pump became. Have I explained this clearly?
New Belts
After sliding the new UDP on with some anti-seize grease on the inner-bore, I started picking from my large array of belts. In the end, I returned an original Nissan belt for the Power Steering Pump. I fully lowered the pump, as far as it would go, and there was still no way the smaller belt recommended in the UDP install was going to fit on. The original belt fits perfectly.
I used Gates K060410 for the larger belt. The recommended K060408 was just a bit too small and K060410 fit nicely.
140 ft/lbs. of Torque
To get the new pulley bolt tightened to 140 ft/lbs. of torque, I used the partner in the driver's seat method. Had somebody sit in the driver's seat, put it in 5th gear, and press the brake pedal for all they were worth. With this method, I easily used my torque wrench to torque up the bolt to 140 ft/lbs. Took very little effort and I was all done.
Results
In the end, there is no squeal or whine since I took care to tighten the belts up to recommended deflection. My first drive around town was for dinner and drinks last night. I didn't notice a great deal of difference, but I'll put the pulley to the test more aggressively in coming weeks I'm sure.
07-07-2002, 04:04 PM
#4
Originally posted by emax95
Nice write up. So what your saying is the stock Power Steering Pump belt works perfectly? That should make this mod a few bucks cheaper for all
Thanks again for the info.
Nice write up. So what your saying is the stock Power Steering Pump belt works perfectly? That should make this mod a few bucks cheaper for all
Thanks again for the info.
07-08-2002, 06:52 AM
#6
Senior Member
Join Date: Apr 2002
Posts: 112
I too had the UPD pulley installed in my 2002 Maxima about 2 months ago. I didn't notice any difference at first however about 4-5 days later I could tell a huge difference. The car definately pulls harder and I can now feel the added horsepower and torque. Several people told me it would take a few days for the ECU to re-adjust due to the weight differences in the stock and UPD pulley. Give it yourself about a week and you'll notice a difference....
07-08-2002, 08:56 AM
#7
Originally posted by 2k2SEmax
I too had the UPD pulley installed in my 2002 Maxima about 2 months ago. I didn't notice any difference at first however about 4-5 days later I could tell a huge difference. The car definately pulls harder and I can now feel the added horsepower and torque. Several people told me it would take a few days for the ECU to re-adjust due to the weight differences in the stock and UPD pulley. Give it yourself about a week and you'll notice a difference....
I too had the UPD pulley installed in my 2002 Maxima about 2 months ago. I didn't notice any difference at first however about 4-5 days later I could tell a huge difference. The car definately pulls harder and I can now feel the added horsepower and torque. Several people told me it would take a few days for the ECU to re-adjust due to the weight differences in the stock and UPD pulley. Give it yourself about a week and you'll notice a difference....
07-08-2002, 09:32 AM
#8
Senior Member
Join Date: Aug 2000
Posts: 351
Interesting. I just installed my UDP this weekend. The my stock power steering belt was just a little too long (after 57000 miles). I ended up using the K040300 which put the adjustment right in the middle of the PS tensionser bolt. The first one (K040292?) was too short. Drove back to Michigan from Philly, noticed a slight increase in power on the butt dyno. More importantly, no noticable affect on PS or AC.
07-08-2002, 09:47 AM
#9
Nice write up on the UDP.
Like some of you I didn't notice an immediate difference and I am unsure If I can tell at all even now. The gains we're getting can't be much really because the only thing that gets underdriven is the Alternator and the AC compressor (I have no idea why some continue to call it the water pump belt
). The biggest difference will come when you use the AC. This unit is about 4 pounds lighter than the stock one so that does help some as well.
A tip I can give some of you about removing the crank bolt is crack the bolt loose when the car is on the ground, in top gear and with the E brake on. Then lift the car up and do the deed. When finished you can torque the bolt back on the same way. On the ground in top gear with the E brake on.
That is correct about the power steering pump being a severe pain in the ****. And it (at least in my circumstances) uses the exact same belt.
Like some of you I didn't notice an immediate difference and I am unsure If I can tell at all even now. The gains we're getting can't be much really because the only thing that gets underdriven is the Alternator and the AC compressor (I have no idea why some continue to call it the water pump belt
). The biggest difference will come when you use the AC. This unit is about 4 pounds lighter than the stock one so that does help some as well.A tip I can give some of you about removing the crank bolt is crack the bolt loose when the car is on the ground, in top gear and with the E brake on. Then lift the car up and do the deed. When finished you can torque the bolt back on the same way. On the ground in top gear with the E brake on.
That is correct about the power steering pump being a severe pain in the ****. And it (at least in my circumstances) uses the exact same belt.
07-08-2002, 09:57 AM
#10
Originally posted by SR20DEN
Nice write up on the UDP.
Like some of you I didn't notice an immediate difference and I am unsure If I can tell at all even now. The gains we're getting can't be much really because the only thing that gets underdriven is the Alternator and the AC compressor (I have no idea why some continue to call it the water pump belt ). The biggest difference will come when you use the AC. This unit is about 4 pounds lighter than the stock one so that does help some as well.
A tip I can give some of you about removing the crank bolt is crack the bolt loose when the car is on the ground, in top gear and with the E brake on. Then lift the car up and do the deed. When finished you can torque the bolt back on the same way. On the ground in top gear with the E brake on.
That is correct about the power steering pump being a severe pain in the ****. And it (at least in my circumstances) uses the exact same belt.
Nice write up on the UDP.
Like some of you I didn't notice an immediate difference and I am unsure If I can tell at all even now. The gains we're getting can't be much really because the only thing that gets underdriven is the Alternator and the AC compressor (I have no idea why some continue to call it the water pump belt
). The biggest difference will come when you use the AC. This unit is about 4 pounds lighter than the stock one so that does help some as well.A tip I can give some of you about removing the crank bolt is crack the bolt loose when the car is on the ground, in top gear and with the E brake on. Then lift the car up and do the deed. When finished you can torque the bolt back on the same way. On the ground in top gear with the E brake on.
That is correct about the power steering pump being a severe pain in the ****. And it (at least in my circumstances) uses the exact same belt.
07-08-2002, 06:09 PM
#13
Originally posted by BlackMax2k1
How can you not tell 9 horses? That's what I have seen printed just so you know.
How can you not tell 9 horses? That's what I have seen printed just so you know.
that 9 horse power gain on your print out, that's probably referring to 9 hp gain to the flywheel..which in real life..not that much to the wheels...
07-08-2002, 06:47 PM
#15
Originally posted by BlackMax2k1
So UDP = waste of $200.
So UDP = waste of $200.
So if you have the $200 to spend and the time to do the job I say go ahead. The worst thing that can happen is that you free up no hp but you still shaved 4 pounds off of the rotational mass of your engine. That HAS to account for something even if we can't see or feel it.
07-08-2002, 06:57 PM
#16
Originally posted by irvine78
that 9 horse power gain on your print out, that's probably referring to 9 hp gain to the flywheel..which in real life..not that much to the wheels...
that 9 horse power gain on your print out, that's probably referring to 9 hp gain to the flywheel..which in real life..not that much to the wheels...
07-08-2002, 09:25 PM
#17
Not DAVEB the parts guy
Join Date: Aug 2000
Posts: 8,555
Instead of trying to figure out if your butt-dyno is miscalibrated, maybe you guys should be testing out at the track and dyno. At the track I observed a drop of .15 seconds and a gain of over 1mph, on average under similar weather conditions. On the dyno, I observed a gain of approximately 4fwhp and tq on the same dyno under the same conditions and correction factors.
Dave
Dave
07-09-2002, 09:55 AM
#22
You know how much hp you would have to get to "feel" anything? Probably over 10hp. So I guess you would be up for a Y pipe, but not an intake, exhaust, cat?
Originally posted by BlackMax2k1
The point of modding is to feel a difference of some kind. If people can't remember any power difference then why pay $200.
The point of modding is to feel a difference of some kind. If people can't remember any power difference then why pay $200.
07-09-2002, 10:08 AM
#23
Supporting Maxima.org Member
Join Date: Sep 2000
Posts: 2,038
Originally posted by Dave B
Instead of trying to figure out if your butt-dyno is miscalibrated, maybe you guys should be testing out at the track and dyno. At the track I observed a drop of .15 seconds and a gain of over 1mph, on average under similar weather conditions. On the dyno, I observed a gain of approximately 4fwhp and tq on the same dyno under the same conditions and correction factors.
Dave
Instead of trying to figure out if your butt-dyno is miscalibrated, maybe you guys should be testing out at the track and dyno. At the track I observed a drop of .15 seconds and a gain of over 1mph, on average under similar weather conditions. On the dyno, I observed a gain of approximately 4fwhp and tq on the same dyno under the same conditions and correction factors.
Dave
The biggest thing I noticed was that coming off the clutch was much easier in 1st.
It shouldn't be a surprise to anyone who reads this forum that the UDP doesn't give you much if anything you can feel on your butt dyno.
07-09-2002, 10:14 AM
#24
Originally posted by Jeff92se
You know how much hp you would have to get to "feel" anything? Probably over 10hp. So I guess you would be up for a Y pipe, but not an intake, exhaust, cat?
You know how much hp you would have to get to "feel" anything? Probably over 10hp. So I guess you would be up for a Y pipe, but not an intake, exhaust, cat?
with that. It pulls harder.
07-09-2002, 12:01 PM
#27
Originally posted by BlackMax2k1
I have a Frankencar intake and I could feel the difference
with that. It pulls harder.
I have a Frankencar intake and I could feel the difference
with that. It pulls harder.
07-09-2002, 02:14 PM
#29
Senior Member
Join Date: Oct 2001
Posts: 1,771
Originally posted by MichaelAE
Based on what?
Based on what?
Tony
07-09-2002, 02:27 PM
#30
Donating Maxima.org Member
Join Date: Mar 2002
Posts: 369
I have used underdrive pulleys for years now. On my 88 Mustang I got .15-.2 second improvement in my 1/4 mile times. On my 98 LS1 Camaro I got .1 and about 8-10 hp on the dyno. I installed a three pulleys system on the Mustang and a crank only on the Camaro. I added the alternator pulley on my Camaro after my testing so I probably have a little more than a tenth improvement now.
Underdrive pulleys do work even if you can't feel the difference. To slow down your accessories you got to be adding hp not to mention a little longevity to your accessories by spinning them slower.
I have always used ASP underdrive pulleys. Maybe all pulleys are not created equal. Unfortunately ASP does not offer one for the 2K2 Maxima yet but when they do I will own one.
Good write up Michael. Thanks for the info!
Underdrive pulleys do work even if you can't feel the difference. To slow down your accessories you got to be adding hp not to mention a little longevity to your accessories by spinning them slower.
I have always used ASP underdrive pulleys. Maybe all pulleys are not created equal. Unfortunately ASP does not offer one for the 2K2 Maxima yet but when they do I will own one.
Good write up Michael. Thanks for the info!
07-09-2002, 04:58 PM
#31
Originally posted by MichaelAE
Well, maybe you have an exceptionally sensitive butt-dyno. Install the UDP and let us know how it goes. In the meantime, I don't see how you can have an opinion about the value-proposition of a UDP without having actually used your own butt-dyno to determine its value. All butt-dyno's are not created equally, you know. I'm constantly complimented on the quality of my butt-dyno, so hopefully once my ECU learns its new lighter/smaller pulley, I will feel the difference.
Well, maybe you have an exceptionally sensitive butt-dyno. Install the UDP and let us know how it goes. In the meantime, I don't see how you can have an opinion about the value-proposition of a UDP without having actually used your own butt-dyno to determine its value. All butt-dyno's are not created equally, you know. I'm constantly complimented on the quality of my butt-dyno, so hopefully once my ECU learns its new lighter/smaller pulley, I will feel the difference.
read like Tony. I don't need to buy the thing and go through the
hard work to install it to find out. If more people say they don't
feel or see a difference that's all I need. It's a lot less work!
07-09-2002, 05:09 PM
#32
Originally posted by BlackMax2k1
My opinion is obviously not based on experience but from what I've
read like Tony. I don't need to buy the thing and go through the
hard work to install it to find out. If more people say they don't
feel or see a difference that's all I need. It's a lot less work!
My opinion is obviously not based on experience but from what I've
read like Tony. I don't need to buy the thing and go through the
hard work to install it to find out. If more people say they don't
feel or see a difference that's all I need. It's a lot less work!
07-09-2002, 05:24 PM
#33
Originally posted by MichaelAE
I don't think a lot of people on this board actually have the thing installed...so there isn't a lot of feedback to go on. I know what you're saying, though...just going on with my bad self.
I don't think a lot of people on this board actually have the thing installed...so there isn't a lot of feedback to go on. I know what you're saying, though...just going on with my bad self.
would be driving a lot more.
07-09-2002, 05:45 PM
#34
Originally posted by BlackMax2k1
Well when your ECU learns it hopefully you can tell a difference. I would be driving a lot more.
Well when your ECU learns it hopefully you can tell a difference. I would be driving a lot more.
07-09-2002, 11:06 PM
#38
Originally posted by BlackMax2k1
My opinion is obviously not based on experience but from what I've
read like Tony. I don't need to buy the thing and go through the
hard work to install it to find out. If more people say they don't
feel or see a difference that's all I need. It's a lot less work!
My opinion is obviously not based on experience but from what I've
read like Tony. I don't need to buy the thing and go through the
hard work to install it to find out. If more people say they don't
feel or see a difference that's all I need. It's a lot less work!