UDP Install and Impressions
09-20-2001, 05:59 AM
#1
UDP Install and Impressions
Well, I finially decided to install my UR UDP Monday night. Its been sitting in my room for months, waiting for belts and the oil seal. Once I got everything I got into my accident, so needless to say, this was put a hold a while.
Install
Install should have been pretty simple.
Removing the stock belts was simple. Getting the bolt off of the stock UDP was far from easy. My roommate was in the car holding the brake, and put the car in 5th gear. It took a good bit of work, but we finially got it off.
The oil seal was easy to get out, just pry it out with a flat head screwdriver. Coat the new one with oil and put it in. A rubber mallet made this a little easier, as its a tight fit.
Here's where it got interesting. I installed the new UDP with no problem. Went to install the PS belt (the smaller of the two) and could not get it on no matter what I tried. Now, UR has a alternate belt size that you can use, but I didn't get that one, I got the smaller one.
So, what I did was take the UDP off, put the belt on it and the PS pully, and then re-install the UDP. This made getting the PS belt on a whole lot easier!
Tensioned the PS belt and moved on the to main belt. This belt is a whole lot easier to get on. It will help to have a second person to hold up the tension pully, otherwise it will be pressing against the belt as you try to get on.
Here is where I ran into a problem. As I was under the car my roommate was lowering the tension pully by tighetening the tension nut. Well, all the sudden we both heard a snap. The tensioner bolt snapped in two! So, this was about 9:30pm, so we called it a night.
Next day I went to my local Nissan Dealers (3 of them) to try to get this bolt. No luck. The nut and bolt costed $13 and they had it overnighted and I got them the next morning (Wednesday).
Impressions
After installing the pully I went out for a spin. First thing I noticed is that there seems to be a lot less engine braking at low speeds.
The car seems to accelerate smoother and quicker throughout the powerband. It will be interesting to see what it does at the track. On the highway this morning I floored it in 5th gear and noriced a lot stronger pull. Other than that I haven't really pushed the car yet...for some reason my head tells me to let the pully and belts "break in", although I don't think this is necessary.
I am going to the track either Friday or next Wednesday, so I'll post my results.
Install
Install should have been pretty simple.
Removing the stock belts was simple. Getting the bolt off of the stock UDP was far from easy. My roommate was in the car holding the brake, and put the car in 5th gear. It took a good bit of work, but we finially got it off.
The oil seal was easy to get out, just pry it out with a flat head screwdriver. Coat the new one with oil and put it in. A rubber mallet made this a little easier, as its a tight fit.
Here's where it got interesting. I installed the new UDP with no problem. Went to install the PS belt (the smaller of the two) and could not get it on no matter what I tried. Now, UR has a alternate belt size that you can use, but I didn't get that one, I got the smaller one.
So, what I did was take the UDP off, put the belt on it and the PS pully, and then re-install the UDP. This made getting the PS belt on a whole lot easier!
Tensioned the PS belt and moved on the to main belt. This belt is a whole lot easier to get on. It will help to have a second person to hold up the tension pully, otherwise it will be pressing against the belt as you try to get on.
Here is where I ran into a problem. As I was under the car my roommate was lowering the tension pully by tighetening the tension nut. Well, all the sudden we both heard a snap. The tensioner bolt snapped in two! So, this was about 9:30pm, so we called it a night.
Next day I went to my local Nissan Dealers (3 of them) to try to get this bolt. No luck. The nut and bolt costed $13 and they had it overnighted and I got them the next morning (Wednesday).
Impressions
After installing the pully I went out for a spin. First thing I noticed is that there seems to be a lot less engine braking at low speeds.
The car seems to accelerate smoother and quicker throughout the powerband. It will be interesting to see what it does at the track. On the highway this morning I floored it in 5th gear and noriced a lot stronger pull. Other than that I haven't really pushed the car yet...for some reason my head tells me to let the pully and belts "break in", although I don't think this is necessary.
I am going to the track either Friday or next Wednesday, so I'll post my results.
09-20-2001, 09:30 AM
#3
Senior Member
Join Date: Aug 2000
Posts: 2,530
Question- which pulley(s) does the UDP replace? I'm assuming power steering, Air conditioner and alternator?
I wouldnt mind toning down the air conditioner and steering but I want my alternator running at full blast. Can I replace all the other pulleys except for the alternator?
I wouldnt mind toning down the air conditioner and steering but I want my alternator running at full blast. Can I replace all the other pulleys except for the alternator?
09-20-2001, 09:37 AM
#4
Originally posted by ericdwong
Question- which pulley(s) does the UDP replace? I'm assuming power steering, Air conditioner and alternator?
I wouldnt mind toning down the air conditioner and steering but I want my alternator running at full blast. Can I replace all the other pulleys except for the alternator?
Question- which pulley(s) does the UDP replace? I'm assuming power steering, Air conditioner and alternator?
I wouldnt mind toning down the air conditioner and steering but I want my alternator running at full blast. Can I replace all the other pulleys except for the alternator?
If you look under your car, its the one right next to the oil filter.
09-20-2001, 06:11 PM
#6
Originally posted by Dave B
What I noticed most was there was absolutely no lag between shifts (ie I was able to hit my shifts harder). OH!! And the fact that I ran 1.5mph faster with my UDP (95.5mph).
Dave
What I noticed most was there was absolutely no lag between shifts (ie I was able to hit my shifts harder). OH!! And the fact that I ran 1.5mph faster with my UDP (95.5mph).
Dave
1.5 mph huh? Not bad. I was hoping to see those kind of gains between the Cat-Back and UDP combined!
09-20-2001, 07:05 PM
#7
Guest
Posts: n/a
Originally posted by Dave B
What I noticed most was there was absolutely no lag between shifts (ie I was able to hit my shifts harder). OH!! And the fact that I ran 1.5mph faster with my UDP (95.5mph).
Dave
What I noticed most was there was absolutely no lag between shifts (ie I was able to hit my shifts harder). OH!! And the fact that I ran 1.5mph faster with my UDP (95.5mph).
Dave
note your ET was worse along with your 60'...
the reason: wheelspin
wheelspin results in a higher mph...
the reason: because you're shifting gears earlier...
(see below for an explanation)
WARNING:
the following explanation may seem like rambling but if you can somehow understand it, it will make sense:
in other words, with wheelspin you hit the shiftpoint quicker which means you shift gears earlier in your trip down the 1320', which means you'll finish your run at a higher rpm than w/o wheelspin, and higher rpm = high mph...
get it? got it? good.
09-20-2001, 10:11 PM
#9
Not DAVEB the parts guy
Join Date: Aug 2000
Posts: 8,555
Originally posted by My 4DSC
that 1.5mph is not the result of your UDP...
note your ET was worse along with your 60'...
the reason: wheelspin
wheelspin results in a higher mph...
the reason: because you're shifting gears earlier...
(see below for an explanation)
WARNING:
the following explanation may seem like rambling but if you can somehow understand it, it will make sense:
in other words, with wheelspin you hit the shiftpoint quicker which means you shift gears earlier in your trip down the 1320', which means you'll finish your run at a higher rpm than w/o wheelspin, and higher rpm = high mph...
get it? got it? good.
that 1.5mph is not the result of your UDP...
note your ET was worse along with your 60'...
the reason: wheelspin
wheelspin results in a higher mph...
the reason: because you're shifting gears earlier...
(see below for an explanation)
WARNING:
the following explanation may seem like rambling but if you can somehow understand it, it will make sense:
in other words, with wheelspin you hit the shiftpoint quicker which means you shift gears earlier in your trip down the 1320', which means you'll finish your run at a higher rpm than w/o wheelspin, and higher rpm = high mph...
get it? got it? good.
Oh really? I guess you don't know me too well then. I'm a "numbers" guy and I look at my timeslips very closely. I want you to chew on these slips and then get you explaination:
Best run to date without UDP:
14.73@93.93mph 2.28 60'
Best mph to date with UDP (not my best et though):
14.91@95.5 with 2.31 60'
Best et with UDP:
14.81@95.08 with 2.30 60'
Sample of runs without UDP and 2.3X+(spinning) 60 foots:
15.21@92.35 with 2.36
15.31@92.11 with 2.55
15.11@91.98 with 2.37
15.03@92.05 with 2.38
15.21@93.15 with 2.42
14.93@92.47 with 2.31
As you can see, the mph to 60' correlation you speak of is all over the place. It is clear to me that last Friday night showed me the UDP did do something. I went from running consistent 93mph traps without the pulley, to running consistent 95mph+ traps with the pulley. Something is giving my the power and the only thing that changed was the pulley. The weather that evening wasn't even remotely close to the weather I ran my best et in plus I was less than .1 off my best et on Friday night (14.81 vs a 14.73). Heck, my 60 foots were only .02 worse (2.30 vs 2.28).
Not trying to flame you.
Dave
09-21-2001, 03:56 AM
#12
Re: UDP Install and Impressions
Originally posted by ejj5875
Well, I finially decided to install my UR UDP Monday night. Its been sitting in my room for months, waiting for belts and the oil seal. Once I got everything I got into my accident, so needless to say, this was put a hold a while.
Install
Install should have been pretty simple.
Removing the stock belts was simple. Getting the bolt off of the stock UDP was far from easy. My roommate was in the car holding the brake, and put the car in 5th gear. It took a good bit of work, but we finially got it off.
The oil seal was easy to get out, just pry it out with a flat head screwdriver. Coat the new one with oil and put it in. A rubber mallet made this a little easier, as its a tight fit.
Here's where it got interesting. I installed the new UDP with no problem. Went to install the PS belt (the smaller of the two) and could not get it on no matter what I tried. Now, UR has a alternate belt size that you can use, but I didn't get that one, I got the smaller one.
So, what I did was take the UDP off, put the belt on it and the PS pully, and then re-install the UDP. This made getting the PS belt on a whole lot easier!
Tensioned the PS belt and moved on the to main belt. This belt is a whole lot easier to get on. It will help to have a second person to hold up the tension pully, otherwise it will be pressing against the belt as you try to get on.
Here is where I ran into a problem. As I was under the car my roommate was lowering the tension pully by tighetening the tension nut. Well, all the sudden we both heard a snap. The tensioner bolt snapped in two! So, this was about 9:30pm, so we called it a night.
Next day I went to my local Nissan Dealers (3 of them) to try to get this bolt. No luck. The nut and bolt costed $13 and they had it overnighted and I got them the next morning (Wednesday).
Impressions
After installing the pully I went out for a spin. First thing I noticed is that there seems to be a lot less engine braking at low speeds.
The car seems to accelerate smoother and quicker throughout the powerband. It will be interesting to see what it does at the track. On the highway this morning I floored it in 5th gear and noriced a lot stronger pull. Other than that I haven't really pushed the car yet...for some reason my head tells me to let the pully and belts "break in", although I don't think this is necessary.
I am going to the track either Friday or next Wednesday, so I'll post my results.
Well, I finially decided to install my UR UDP Monday night. Its been sitting in my room for months, waiting for belts and the oil seal. Once I got everything I got into my accident, so needless to say, this was put a hold a while.
Install
Install should have been pretty simple.
Removing the stock belts was simple. Getting the bolt off of the stock UDP was far from easy. My roommate was in the car holding the brake, and put the car in 5th gear. It took a good bit of work, but we finially got it off.
The oil seal was easy to get out, just pry it out with a flat head screwdriver. Coat the new one with oil and put it in. A rubber mallet made this a little easier, as its a tight fit.
Here's where it got interesting. I installed the new UDP with no problem. Went to install the PS belt (the smaller of the two) and could not get it on no matter what I tried. Now, UR has a alternate belt size that you can use, but I didn't get that one, I got the smaller one.
So, what I did was take the UDP off, put the belt on it and the PS pully, and then re-install the UDP. This made getting the PS belt on a whole lot easier!
Tensioned the PS belt and moved on the to main belt. This belt is a whole lot easier to get on. It will help to have a second person to hold up the tension pully, otherwise it will be pressing against the belt as you try to get on.
Here is where I ran into a problem. As I was under the car my roommate was lowering the tension pully by tighetening the tension nut. Well, all the sudden we both heard a snap. The tensioner bolt snapped in two! So, this was about 9:30pm, so we called it a night.
Next day I went to my local Nissan Dealers (3 of them) to try to get this bolt. No luck. The nut and bolt costed $13 and they had it overnighted and I got them the next morning (Wednesday).
Impressions
After installing the pully I went out for a spin. First thing I noticed is that there seems to be a lot less engine braking at low speeds.
The car seems to accelerate smoother and quicker throughout the powerband. It will be interesting to see what it does at the track. On the highway this morning I floored it in 5th gear and noriced a lot stronger pull. Other than that I haven't really pushed the car yet...for some reason my head tells me to let the pully and belts "break in", although I don't think this is necessary.
I am going to the track either Friday or next Wednesday, so I'll post my results.
09-21-2001, 04:46 AM
#13
Originally posted by ohboiya
Do we really need a new oil seal?
Do we really need a new oil seal?
09-21-2001, 07:51 AM
#16
Guest
Posts: n/a
Originally posted by Dave B
Oh really? I guess you don't know me too well then. I'm a "numbers" guy and I look at my timeslips very closely. I want you to chew on these slips and then get you explaination:
Best run to date without UDP:
14.73@93.93mph 2.28 60'
Best mph to date with UDP (not my best et though):
14.91@95.5 with 2.31 60'
Best et with UDP:
14.81@95.08 with 2.30 60'
Sample of runs without UDP and 2.3X+(spinning) 60 foots:
15.21@92.35 with 2.36
15.31@92.11 with 2.55
15.11@91.98 with 2.37
15.03@92.05 with 2.38
15.21@93.15 with 2.42
14.93@92.47 with 2.31
As you can see, the mph to 60' correlation you speak of is all over the place. It is clear to me that last Friday night showed me the UDP did do something. I went from running consistent 93mph traps without the pulley, to running consistent 95mph+ traps with the pulley. Something is giving my the power and the only thing that changed was the pulley. The weather that evening wasn't even remotely close to the weather I ran my best et in plus I was less than .1 off my best et on Friday night (14.81 vs a 14.73). Heck, my 60 foots were only .02 worse (2.30 vs 2.28).
Not trying to flame you.
Dave
Oh really? I guess you don't know me too well then. I'm a "numbers" guy and I look at my timeslips very closely. I want you to chew on these slips and then get you explaination:
Best run to date without UDP:
14.73@93.93mph 2.28 60'
Best mph to date with UDP (not my best et though):
14.91@95.5 with 2.31 60'
Best et with UDP:
14.81@95.08 with 2.30 60'
Sample of runs without UDP and 2.3X+(spinning) 60 foots:
15.21@92.35 with 2.36
15.31@92.11 with 2.55
15.11@91.98 with 2.37
15.03@92.05 with 2.38
15.21@93.15 with 2.42
14.93@92.47 with 2.31
As you can see, the mph to 60' correlation you speak of is all over the place. It is clear to me that last Friday night showed me the UDP did do something. I went from running consistent 93mph traps without the pulley, to running consistent 95mph+ traps with the pulley. Something is giving my the power and the only thing that changed was the pulley. The weather that evening wasn't even remotely close to the weather I ran my best et in plus I was less than .1 off my best et on Friday night (14.81 vs a 14.73). Heck, my 60 foots were only .02 worse (2.30 vs 2.28).
Not trying to flame you.
Dave
Just trying to inform people here about the relationship between 60' and 1320 MPH/ET...because many people don't get it and it's very important...especially with regards to racing/tuning FWD vehicles...
I'd be curious to see the list of ET/MPH *with* the UDP...
Also the 330', 660', and 1000' give you some good info too...
There's alot more to a run than just 60' and 1320'...
Especially when the correlation is all over the place (not consistent)...For example:
"15.03@92.05 with 2.38"
"15.21@92.35 with 2.36"
Like between these 2 runs, I'm wondering what happened inbetween the 60' and 1320' for you to run 2/10ths slower with a BETTER 60'....
I'm guessing you were trying different shift points...or missed a gear?
I wasn't there and haven't seen your full timeslips yet but by the info I was given I still don't see that 1.5mph being a result of the UDP...who knows?
When traction was a problem for me, I myself would see huge differences in MPH of +/- 5mph...
Back when I was supercharged, a 2.4 60' run would yield 105+mph at 14.0+ ET whereas a 2.2 would yield 102mph at a 13.8 ET.
Sorry if you took offense to my little class on traction...I wasnt preaching to you...I was trying to inform the community at large...I was just using your #'s as an example...
09-21-2001, 12:20 PM
#17
Not DAVEB the parts guy
Join Date: Aug 2000
Posts: 8,555
I didn't take it as a flame, but the spinning 60 foot = high trap speeds just doesn't seem to apply much to FWD cars. My 60 foots are so close (within a .1) that I don't see how it could be responsible for a fairly dramatic 1mph+, consistently. Like you said, it is a hard thing to explain. Looking at all my timeslips and comparing my Friday night runs with 95mph trapspeeds to the April runs without the pulley look like this. Friday night I was getting 1/8th miles in the 9.60 range @74-75mph with the 2.30 60 foots. In April I was running lots of 14.7s,14.8s, and 14.9s with 1/8th miles in the 9.45 range @74 with 2.25-2.28 60 foots. By comparing the numbers for the 330', 1/8th, and 1000', it looks to me that I'm picking up mph in the topend. My shift points stayed the same:
1-2 6500
2-3 6300
3-4 6100
Dave
1-2 6500
2-3 6300
3-4 6100
Dave
09-22-2001, 05:06 AM
#19
Originally posted by ny96maxse
question for any one with the UDP:
will this mod make any difference if im an automatic with a cattman Y pipe and apexi ws-catback and CAI??
opinions/reccomendations only please!!
Anthony
question for any one with the UDP:
will this mod make any difference if im an automatic with a cattman Y pipe and apexi ws-catback and CAI??
opinions/reccomendations only please!!
Anthony
09-22-2001, 06:21 AM
#20
Senior Member
Join Date: Jan 2001
Posts: 2,105
question about pulleys
could i have my stock pulleys lightened? i wouldnt mind having my AC and power steering toned down (like someone else said) but i need all the juice i can get from my altinator at all times (soon to be a 1500watt stereo will do that).
thanks.
thanks.
09-22-2001, 06:38 AM
#21
Guest
Posts: n/a
Originally posted by Dave B
I didn't take it as a flame, but the spinning 60 foot = high trap speeds just doesn't seem to apply much to FWD cars.
Dave
I didn't take it as a flame, but the spinning 60 foot = high trap speeds just doesn't seem to apply much to FWD cars.
Dave
09-22-2001, 12:42 PM
#24
Originally posted by UMD_MaxSE
cool.... did you get the right belts? Coz refunded me like $20 for the ones I sent back....
cool.... did you get the right belts? Coz refunded me like $20 for the ones I sent back....
I'll let u guys know!
09-22-2001, 01:04 PM
#25
Originally posted by ohboiya
really? he only offered me $18? ... LOL .. n e ways .. I didn't return .. he just sent the right one out ... haven't installed them yet ...
I'll let u guys know!
really? he only offered me $18? ... LOL .. n e ways .. I didn't return .. he just sent the right one out ... haven't installed them yet ...
I'll let u guys know!
Thread
Thread Starter
Forum
Replies
Last Post