unorthodox underdrive crank pulleys?
02-16-2004, 02:04 PM
#2
wouldn't say by that much. i have it, but haven't dynoed yet. light makes right - the weight difference between the stock and ur pulleys is like night and day. if you've got the time, money, and patience to do it, i'd say go for it.
02-16-2004, 02:09 PM
#3
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Join Date: Sep 2002
Posts: 96
Originally Posted by raidwolf
wouldn't say by that much. i have it, but haven't dynoed yet. light makes right - the weight difference between the stock and ur pulleys is like night and day. if you've got the time, money, and patience to do it, i'd say go for it.
You install yourself or did you pay someone?and how much did hte install cost?
02-17-2004, 09:40 AM
#9
it will make your car faster, give it a lot more low-end torque without losing power on mids and highs , a udp is hard to install on a 02-03 maxima because there is not much room to work but i think the mod is worth its money
02-17-2004, 09:44 AM
#10
Senior Member
Join Date: Mar 2002
Posts: 780
Gives some gain...I can feel it.
Can't you tell the difference in how the car performs when you have the front window defrost on or AC on? Similar idea.
I did it myself...it really wasn't that hard, but helps having an extra set of hands around (like any install).
Can't you tell the difference in how the car performs when you have the front window defrost on or AC on? Similar idea.
I did it myself...it really wasn't that hard, but helps having an extra set of hands around (like any install).
02-17-2004, 09:45 AM
#11
I didnt think it was that bad to install. Only thing that gave me trouble was my broken tensioner pulley (stupid, stupid me). But otherwise, it just took a little time to loosen some bolts. It wasnt difficult really. And in my race against a 2k2 auto SE Maxima (stock minus muffler) I pulled on him all thru 1st gear. This was at the track and I have the slips for the race... once into 2nd gear, neither one of us could pull an inch away, so I credit my UDP for the quicker pull thru 1st. Told many people that, so ya, get one 
02-17-2004, 09:59 AM
#12
http://www.nissanperformancemag.com/...r02/altima_ur/
"Adding the crank pulley can be a little deceiving compared to other mods because there isn't a definite surge anywhere in the powerband, so the seat of the pants dyno is no good here. To verify the increases we headed up to R & D dyno to measure the results. There's a progressive gain in power of 2-3 hp from 2-4K RPM, after this the increase in hp is approximately 4-5 until 5K RPM where we gained 6.5 hp over stock and 3 lb ft of torque."
"Adding the crank pulley can be a little deceiving compared to other mods because there isn't a definite surge anywhere in the powerband, so the seat of the pants dyno is no good here. To verify the increases we headed up to R & D dyno to measure the results. There's a progressive gain in power of 2-3 hp from 2-4K RPM, after this the increase in hp is approximately 4-5 until 5K RPM where we gained 6.5 hp over stock and 3 lb ft of torque."
02-17-2004, 10:03 AM
#13
Most bolt ons dont give a noticable increase in acceleration. You gotta bring it to the track or dyno. I think that the track is the best way to decide. Just take a look at trap speeds and that gives ya a good indication of the power you're makin
02-17-2004, 02:44 PM
#14
Originally Posted by 2k2maxpower
You install yourself or did you pay someone?and how much did hte install cost?
02-17-2004, 03:44 PM
#16
Senior Member
Join Date: Dec 2002
Posts: 238
Originally Posted by raidwolf
did it myself. studman's got a nice write-up on it (forgot his webpage).
02-17-2004, 04:17 PM
#17
how can you say...
and then say...
???
yes it does free up a few hp and yes it will show on a dyno.
Originally Posted by Xplayboy69x
it will not add hp on a dyno
Originally Posted by Xplayboy69x
it will make your car faster, give it a lot more low-end torque without losing power on mids and highs , a udp is hard to install on a 02-03 maxima because there is not much room to work but i think the mod is worth its money
yes it does free up a few hp and yes it will show on a dyno.
02-18-2004, 05:03 PM
#20
Donating Maxima.org Member
Join Date: Jul 2003
Posts: 188
Originally Posted by Xplayboy69x
it will not add hp on a dyno
Energy in your engine is created by the explosion of gas in the cylinder. ALL that energy goes somewhere, most is given off as heat, but the part we worry about travels down the crankshaft.
There is the inertial weight of the crankshaft (happens to have a 12 pound pulley bolted to the end.) For most models this will be reduced by around 7 pounds. According to unorthodox, 80% of the HP gain comes from the lighter weight.
Second, some of that power goes to turn the alternator, A/C, power steering, etc... Why do you start driving in 1st instead of 4th gear? Gear ratio... Your car goes slower but has an easier time getting there. Same effect here.
Example, if you had your car on the dyno, and your accessory belt just broke in the middle of a run, would you see a spike? Sure would... That's the small percent of the energy from that spark in your engine that runs the components. It now travels down the crankshaft into the tranny instead of being used by the accessories.
Energy moves the graph up the dyno, so if it's not going to the accessories or being used to overcome inertial weight, etc... It travels down the drivetrain.
Pop quiz tommorow...
02-19-2004, 10:00 AM
#22
Member
Join Date: Jun 2003
Posts: 79
i think quicksilver is trying to start a GD on all the unorthodox products. heres the forum link:[SIZE=2]
http://forums.maxima.org/showthread.php?t=270090
http://forums.maxima.org/showthread.php?t=270090
02-19-2004, 01:54 PM
#23
Not DAVEB the parts guy
Join Date: Aug 2000
Posts: 8,555
Originally Posted by KCMichaelM
Sorry, sure will, for 2 reasons....
There is the inertial weight of the crankshaft (happens to have a 12 pound pulley bolted to the end.) For most models this will be reduced by around 7 pounds. According to unorthodox, 80% of the HP gain comes from the lighter weight.
There is the inertial weight of the crankshaft (happens to have a 12 pound pulley bolted to the end.) For most models this will be reduced by around 7 pounds. According to unorthodox, 80% of the HP gain comes from the lighter weight.
Dave
funny how i got HP on a dyno on my other nissan...i think you mean a FLYWHEEL..not pullies...
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