While farking up something else, I noticed that my drive belts need to be replaced. I looked through the old paperwork from the original owner, and they were never replaced... of course, he sold the car to me at 53k miles. The belts look fine on the outside, some very small fraying. But, the inside of the belts are all cracked and I figured I'd rather be safe than sorry.

Anyway, I don't upgrade much, unless I'm having to replace an oem part. Well, the belts need to be replaced, so I figured it was also a good time to go the ur pulley route. I've noticed, through searching, that some people do the 2 pulley, some replace 3 and a few replace all 4.

Replacing just 2 seems to be the most popular, with 3 in a close 2nd and replacing all 4 is way back in the pack. From experience, what benefits have some of you had from going any of these routes and would you do the same again?

I also came across that some of the members had wished they hadn't replaced the pulleys at all, that the benefits just don't justify the money and the gains. Right now, I have a pretty stock motor. Just a CAI, and solid mounts to put a couple more whp down. I understand that the pulleys are lighter weight, which frees up a couple of hp and allows the engine to rev a bit quicker.

I found the 4 piece set for $350, but I don't think it includes shipping. My greedyness says to purchase the 4 pc set, but my practicallity says go for the 2 piece set. My total goal for the car, at least hp wise, will include header and exhaust... no cams.

Any thoughts from those who have personally gone this route?

Peace,
Mark

i looked into and there was an article on it and it said that the 2pc set freed about 4hp while the 4pc set freed about 6-8 hp but either way it makes the car run alot smoother no studdering at idle i'll try to find the link for it for ya but in my opinion i think it would just be a better deal to get the 4pc *** if yuou want to get the other 2 later you'll being paying more then necessary...just my opinion

I'll take a 4 piece (dark) with mashed potatoes and dirty rice. :)

Travis

Quote:
Being skeptical of the claims for big horsepower on the Unorthodox Racing web site, we ordered up a set of their underdrive pulleys to do some extensive dyno testing. Joe at Unorthodox told us via a phone conversation that he felt that the pulleys would be good for about 5 hp on the SE-R.

When received, the pulleys were obviously CNC machined from billet aluminum and anodized a nice shade of blue. They were significantly lighter than the stock bits. We measured the TDC mark in relation to the keyway to make sure that the TDC mark was right on. It was. Unfortunately the TDC mark is the only one on the pulley so timing the car without a dial back timing light is impossible. Not a big deal for us as we have one of these timing lights but possibly a problem for the average joe. We suggest that Unorthodox add marks in 5-degree increments to the pulley instead of just a TDC mark.

To install the pulleys, we removed the passenger side wheel and wheelwell splash shield, exposing the front of the engine. An air impact was then used to remove the main pulley nut. The 10mm bolts holding the water pump pulley were removed with the belt still in place to prevent them from spinning. Two 6mm bolts were used in the existing holes to lever the stock main pulley off the crank. I don't really recommend doing this as it is real easy to punch a hole in the front cover this way. Use a puller or back up the bolts with a peice of thick metal to prevent damaging the cover. To get enough clearance to completely remove the main pulley, the passenger side motor mount had to be loosened and a jack placed under the motor to lift it slightly shifting the engine enough to get the pulley off. The new pulleys were installed in reverse order.

The stock belt for the water pump and AC compressor could be retained but a shorter belt was necessary for the alternator and power steering. We used a Bando p/n 6PK-1000 belt to replace the stock belt which was purchased from World Pack, a nearby parts house (1-800-733-2277). Bando makes genuine Nissan belts so I figured the quality of this replacement belt should be good.

After running the car, my SOTP estimate of power gain was small, about 1-2 hp. The engine felt more eager to rev and there was less drag when the AC compressor kicked on. I plugged in a CONSULT to test for charging function and overheating. The battery output stayed above 12 volts with all electrical accessories going full blast, including my aftermarket PIAA lights and 200-watt stereo cranking. When I made the electric windows go up and down at the same time the voltage dipped to 11.9 volts but I seriously don’t think that is a realistic estimate of potential power demand. I don’t think you would be caught in a very hot, very humid, foggy rain storm at night while broken down on the side of the road, engine at idle with every single light on, fogging up the windows while making out with your girl (or guy) stereo blaring and get a bug to roll the windows up and down to the beat of the music while waiting for the tow truck! If you do this frequently you may discharge your battery with the underdrive pulleys.

I tried to make the car overheat in bumper to bumper traffic on an 80-degree day, plus high speed cruising and free revving the motor to 7000 rpm for a few minutes. The coolant temp never went above 94 degrees C. I also did some violent slalom maneuvers to test the power steering. There was no sign of power steering pump up. The AC was perhaps a little less effective but it was hardly noticeable. After all this testing I conclude that the pulleys are at least safe. I think that under racing conditions the car may even run cooler as the stock water pump is prone to cavitate at over 6500 rpm.

Some list members have been concerned that the underdrive pulleys lack of an inertia ring as the one in the stock pulley could have some negative effects on motor life. I believe that this is not true. The SR20, unlike most domestic motors, has a fully counterweighted crankshaft and is internally balanced. It does not rely on a counterweight on the front pulley and flywheel to give dynamic balance like Ford or Chevy engines. Highly modified domestic motors are internally balanced at a great cost but us Nissan owners get that stock! I believe that the damper on the stock pulley is mostly to damp out accessory drive noise. With the underdrive pulley in place there actually seems to be less idle and high rpm vibration. I could not detect any increase in accessory drive noise but my car is sort of loud.

The next step was the acid test on DPR’s Dynojet chassis dynamometer. Amazingly the pulleys were good for a maximum of 6 hp over stock! The increase was about 2 hp at 2000 rpm rising in proportion with rpm to 5 hp at the power peak to 6 hp at the rev limit. The smooth gradual increase of power deceptively made the SOTP feel less. Normally most mods put a hump somewhere in the powerband that is easy to feel. Not so for the underdrive pulleys. Their seamless addition of power was very hard to feel. Being a skeptic we ran the car three more times to see if it was a fluke. All three runs yielded the same results.

At $189 list price these pulleys get our bang for the buck award! There are often group deals for less on the se-r mailing list.

Unorthodox has introduced a 4 piece pulley set that includes the power steering and alternator pulleys also. I have tested these and found perhaps a small 1 hp gain over the old 2 piece set. Shell Black has found a larger about 2-3 hp gain in his testing. Surprisingly I can feel a larger SOTP difference with the 4 piece set. Taking our suggestions, Unorthodox has improved the pulleys by adding a steel sleeve under the front main seal for longer life and is now adding all of the correct timing marks. The new product is even better.

We have also tested the pulleys extensively on the racetrack at temperatures over 100 degrees and found that the pulleys significantly reduce water pump cavitation induced overheating. Despite thrashing on a road course which is much harder on a motor than drag racing, we have yet to see any increase in wear on the motor.


That is Mike Kojima's review from www.se-r.net.

swiss posted this for me

$189 for the 4 pc set? I'm thinking this is old information, especially if pulled from se-r.net. I guess it would be a good time to invest in an electric impact wrench, and rent a pulley puller. Good to here that unorthodox put the timing marks on there pulleys.

So, stock sized belt for water pump and alternator and then the different sizes for the others. Also, during searching, I did find the right Gate and Goodyear belt sizes. I remember searching the mailing list archives, but I didn't include se-r.net... should have.

Peace,
Mark

go for the full 4 piece set.

stratton.

Mark,

Here are my thoughts on it. I'm thinking very hard about just a 2 piece pulley set for my NX. I'm planning on the water pump (to eliminate/reduce cavation during track days) and the power steering pump b/c I'm going to re-install p.s. over the winter, and it will be easier to put the pulley on out of the car.

This should also just require 1 new belt (if I remember correctly that the p.s. and water pump are on the same). I can always do the AC if I want later on.

I know from some of your posts you are flirting w/ a VE, if you ever need a motor; and I'm not comfortable running a pulley on that motor if conventional wisdom says otherwise - I know others have had good luck so far. So that (the crank pulley) could be a waste of money if you went that route.

Pulling the stock crank pulley off of my VE was a minor PITA while on the stand, so that is another reason I don't want to do it in the car.

Don't forget that Mossy is working on their own pulley set. The water pump I think was posted in the VE section a couple weeks ago or so.

Knowing the time you will have to do the install (w/ kids), you might want to wait until you have an entire day free for the pulley install - just a guess though. :)

Good luck,

Josh

The ve would be at least a couple of years down the road, unless my new career jump starts sooner than expected. But, I just figured since I'm going to have to pull the belts anyway, and I'm "down" there, I might as well replace the pulleys.

Josh, actually you're probably right. I do want a ve, so I think I'll just replace the belts, forget the header and exhaust for this engine, and finish the suspension. For some reason, I've been hoarding parts for my suspension longer than any other upgrade, yet it never gets finished.

Heck, now I'm going to have to really think about this. The one benefit of getting the pulleys is that I can use the household account instead of my "stash". While for the ve, I'd have to really grow the stash much larger than it is now. Things break or get worn... household account. Things replaced/upgraded because I "want" to do them... my stash.

Peace,
Mark

I am running the 2pc. set myself for about the past 2yrs. when I puchased mine they were just a little over $200. And at that same time the 4pc. were going for close to $500. So I was like for that much more in price it wasn't worth it to me to get the 4pc. Now if you can pick up a set for cheap then go for it btw keep us posted on what you decide.

Things break or get worn... household account. Things replaced/upgraded because I "want" to do them... my stash.

That's how I do it. The joys of married life and kids. :tongue: That's why it tooks 9 months for my Fuji and another 3 months for my exhaust - which isn't on yet.

Back on subject, the cost of the 4 piece set is also a deterent for me. The Mossy WP pulley is ~$50, so that is resonable. You could do that along w/ the actual pump (since it is probably original) and belts for a nice project that will give you some added piece of mind while on the track - better cooling.

Josh

I would stick with the 2 pc since the extra $ for the 4pc is not worth it IMO.
FWIW, here is a pic of my Mossy VVL WP pulley and crank pulley that I will be using on my DE.
http://tinypic.com/f4he04.jpg

I love my two piece set. Excellent mod. The engine seems more eager to rev.

Feels about like the addition of a lightweight flywheel. Another mod that you could consider next time you are doing something to the clutch.

And as long as I'm sorta on topic..... ;)

The AC doesn't seem to drag the car down like it used to, and is this possible.....the AC doesn't cycle off as often? I think these observations are correct, and an added bonus.

I think with my time constrainsts, josh mentioned them;), the 2 pc would be a "smarter" move for me. Less money invested and less time wasted.

I must of misread one of the above posts, but are y'all saying that Mossy now puts out a 2 pc set that's equivalent to the ur set or is Mossy's just for the ve? I'd rather give my money to Mossy, they've been a huge supporter of our cars for years.

Peace,
Mark

Mossy only has the crank and water pump available now. I believe they were hoping to get the rest available soon, but I haven't seen an ETA on the others. The crank I thought I read was a copy of the VE - but I'm not sure if the N1 is the same as the other VE's (doubt it).

Josh

I might have missed it here(not sure if someone mentioned this)but the 2 piece is easier to install...I believe you need to remove the P.S. pump and Alt. in order to put them on...Thats probably why most guys have the 2 piece

Wow...I remember when I paid $360 for my 4 peice set. $189 now?

will the mossy at least match the ur in terms of gains, 2 pc to 2 pc?

Wow...I remember when I paid $360 for my 4 peice set. $189 now?
I believe they mean $189 for the two piece set.

Also, I have never heard of a 3 piece set :confused:

I was wondering if someone could explain what exactly happens to the water pump pulley after 6,500 rpm's? And how the Mossy WP pulley would help?

Thanks,
-Mike

WP pulley spins too fast and @ or after 6500rpm, the water "cavitates". Instead of moving smoothly while being pushed by the Water pump it becomes trurbulent and its flow (water volume) goes down.

ANy underdrived WP pulley spins slower than stock (that's the definition of "underdriving" after all) and does not reach the rpm where water cavitation occurs.