Ultra S Unorthodox Racing Underdrive Crank Pulley [Archive]

Shades

05-28-2004, 04:06 PM

Other day I finally installed my new blue UR Underdrive pulley in, and I can say the gains were unexpected. The instructions (which were somewhat inadequate) said it would take 5-7 days for full hp gains, but I noticed there was already new piss and vinegar in the pro right after installation. The installation took about 2 hours, but I could do it again in probably 30 minutes now that I know my way around the pulley system better. Sorry, no real pics, but if anyone has questions on how to install one of these beauties, just pm, and I'll tell you all you need to know. (Like how to get the original pulley off of an automatic)

New performance like this definitely calls for a pelvic thrust! (hump)

Rism

05-28-2004, 04:56 PM

Sweet im looking to invest in one. Where did you pick yours up? Also what RPM range do u see most ur gains in?

birdy85

05-28-2004, 07:34 PM

how did you get the stoc belts off

Shades

05-28-2004, 08:26 PM

I got mine from http://www.revolutionsmotorsports.com on clearance. (fast shipping too)

To get the stock belts off, first you gotta locate the tensioner screws (There's one hooked to the alternator, and there's one near the front of the engine, just under the highest pulley. They both look about the same, long brass bolt with mostly exposed threads.)

To get the one from the front of the engine, you have to loosen two red-painted bolts. One of them is the fastener bit on the screw, very easy to find just under the pulley. The other is the hinge that the pully hooks onto the engine block with. These aren't easy to loosen, and you'll probably hear some loud "CRACK" but crank em anyway till they're loose and the pully can move along the screw. Once these are loosened, you can just turn the tensioner screw until the pulley is loose enough for the belt to fall off.

The one on the back (on the alternator) is along the same premise. I don't remember the exact setup (my buddy took that side) you gotta loosen the fastener on the tensioner, and anything that keeps the part from moving along the tensioner's screw threads.

Pics would really help here, I know, but i don't got a digital camera :(

Oh yeah, and RPM range, I noticed the difference more in the lower RPM's... just above idle the most, but the gains stretch pretty well across it.

A.V.MSP

05-29-2004, 05:38 AM

I want to get this pulley for my msp do you guys know if there is people running them with no probs cuz I heard the oil pump has probs or some thing like that.

Shades

06-01-2004, 03:00 PM

I'll get back to you in 20K miles

Protege_Speed

06-02-2004, 10:19 PM

Ok. So I bought my pulley. I haven't installed it yet but I wanted to see what I was getting into and I decided to take some pics at the same time. Look at these pics and see if they help with your how-to.

I got mine from http://www.revolutionsmotorsports.com (http://www.revolutionsmotorsports.com/) on clearance. (fast shipping too)

To get the stock belts off, first you gotta locate the tensioner screws (There's one hooked to the alternator, and there's one near the front of the engine, just under the highest pulley. They both look about the same, long brass bolt with mostly exposed threads.)

To get the one from the front of the engine, you have to loosen two red-painted bolts. One of them is the fastener bit on the screw, very easy to find just under the pulley. The other is the hinge that the pully hooks onto the engine block with. These aren't easy to loosen, and you'll probably hear some loud "CRACK" but crank em anyway till they're loose and the pully can move along the screw. Once these are loosened, you can just turn the tensioner screw until the pulley is loose enough for the belt to fall off.

The one on the back (on the alternator) is along the same premise. I don't remember the exact setup (my buddy took that side) you gotta loosen the fastener on the tensioner, and anything that keeps the part from moving along the tensioner's screw threads.

Pics would really help here, I know, but i don't got a digital camera :(

Oh yeah, and RPM range, I noticed the difference more in the lower RPM's... just above idle the most, but the gains stretch pretty well across it.

Protege_Speed

06-02-2004, 10:21 PM

Roywhitep5

06-02-2004, 10:25 PM

i am also intrested in this mod. after you get past 5k miles and have no problems, i think i might get one. did you need new belts?

Protege_Speed

06-02-2004, 10:35 PM

I hope there will be no problems. I did get the Gates belts but I haven't installed it yet. I will let you know how it goes.

i am also intrested in this mod. after you get past 5k miles and have no problems, i think i might get one. did you need new belts?

upstop

06-02-2004, 11:28 PM

I want to know how gas milege is affected, What diamater the pulley's are (stock & aftermarket).

Were you able to swap it easy enufgh from under the car? I have only looked at it from the top of the engine bay and my thought was to pull the motor and the swap would be cake.

viVid

06-03-2004, 12:39 AM

I have had mine on for at least 10k, if not 15k... no problems. I used Gates belts (highly recommended).

i am also intrested in this mod. after you get past 5k miles and have no problems, i think i might get one. did you need new belts?

akhilleus

06-03-2004, 02:15 AM

I have had mine for 30k w/ a system. I have had some problems with my belts slipping but i have the silver unanodized version and i dont have gates belts, yet :(
Tightening may be required too. However i havent had any water pump, alternator, or ac problems. it does chirp a bit though, voltage drops are somewhat noticable too.

A.V.MSP

06-03-2004, 02:21 AM

can you get gates belts from any auto zone or pep boys?

akhilleus

06-03-2004, 02:25 AM

i think that their availability is limited. probably not pep boys, autozone could order them. Belt #'s are included with the pulley and are also on unorthodox's website.

A.V.MSP

06-03-2004, 02:36 AM

thanks man you probably just saved me a few gallons of gas from drivin all over town like a dumb ass :)

akhilleus

06-03-2004, 02:37 AM

no problem, how are the indiglo alt. and water pulley sets?

A.V.MSP

06-03-2004, 02:52 AM

Im happy with them. no charging or overheating problems yet. Its been 90-100 degrees the past few days and drove the car extra hard to make sure that the water pump still wored just fine. Power gains are not spectacular but deffinately noticeable and in my oppinion worth the $, but ill take any little bit I can. Hopefully when I get the UR pulley it will compliment the indigos that much more

akhilleus

06-03-2004, 02:46 PM

are they smaller than stock or larger? Do u have any slipping, alt. voltage issues?

A.V.MSP

06-03-2004, 02:49 PM

the wterpump is the same size but the alternator pulley is slightly bigger. maybe a 1/4-1/2" biger. No charging problems, no overheating at all and it has been 90-100 degrees past few days including today. Headlights dont dim or anything. If you are running a system you might have charging problems but dont know for sure cuz I have the stock MSP one still.

Shades

06-03-2004, 02:50 PM

Put over a thousand on it over the last 2 weeks, still more smiles than miles. :)

The queerbaits I ordered my belts from gave me 2 of the same belt, so I ended up having to use one of the stock belts with the tensioner pushed out a bit further than normal, and after 1000 miles, it's still fine (though I do have an extra belt now in the trunk just in case...)

As for putting it on, u can do it just by opening the hood and jacking up the car easy enough. U might get burned on the valve cover if u can't wait long enough to let it cool, and might cut urself getting some of the sockets on, but it's not too hard, but hey, that's working on a car for ya

A.V.MSP

06-03-2004, 02:59 PM

nice to know. You just have the UR pulley right? so you are using the stock belt? I had to adjust the tensioner to get the belt tight for the indigo pulleys, but still no slipping.

P-Funk!

06-04-2004, 02:38 PM

Ok! Based on this - i went to unorthodox and bought the pulley! I didn't see the p/n for the belt tho'...

What is it - so i can install it the day i get it!! :D

akhilleus

06-04-2004, 02:59 PM

It will be in the instructions included for your vehicle. It is also on their website since i have spoken to them about it specifically, look for vehicle installation instructions or email them.

CrazyCaker

06-04-2004, 03:24 PM

I've been running the UR pulley now for about 5,000km. No problems what so ever (using Gates belts btw). The gains are very noticable in the lower RPM range, but like mentioned stretch throughout the powerband.

Protege_Speed

06-04-2004, 10:51 PM

So guys I need a little help here. I have decided to do the install myself but how do you loosen the crank pulley and keep it from turning? What's the secret? I have an automatic. Does anyone have a shop manual?

viVid

06-04-2004, 11:54 PM

The way I did it was to have my wife in the car, have her put it in 5th gear, and then mash the brakes. Another way to do it would be to drop the oil pan and wedge in a piece of wood between the crank and block. You can also try an air drive, but my 1/2" wouldn't touch it.

So guys I need a little help here. I have decided to do the install myself but how do you loosen the crank pulley and keep it from turning? What's the secret? I have an automatic. Does anyone have a shop manual?

Shades

06-05-2004, 12:59 AM

with the automatic, we did it with a chain wrench on the hill between the belts. (Or, if you don't mind possibly damaging your pully, just wrap the chain on) You just gotta clamp it on, move it so it's braced against something, then turn the bolt with some good force, and ur in business.

To get it back on, I wrapped one of the old belts around the UR pulley, and clamped the chain down on top of that. Hope this helps

Installshield 2

06-05-2004, 02:21 AM

So is this UR pulley the stock pulley's size? Haven't researched it much...Lots of cars have smaller ones, and bigger ones available...for different types of benefits...The oscillation rumors will most likely never come into play until huge power mods are made, so you guys have absolutely nothing to worry about reliability wise I would imagine...I wouldn't do it on a cast crank, but ours should be fine...

akhilleus

06-05-2004, 02:35 AM

its smaller diameter and lighter. I personally had the pulley installed by a good shop enar me, it wasnt expensive either. Some things i will work on but the pulley location, lack of a lift, and the little space in which to work made me shy away from a DIY project. Otherwise install is right about the fact that this pulley seems to be reliable.

Protege_Speed

06-05-2004, 04:22 AM

I did it!!! Thanks for the suggestions guys but since mine is an auto, it was alot more difficult than I expected. One problem was getting the bolt loose but it's not over yet. After you put the new pulley on, you now have to torque that to 121ft/lbs. This was definitely a difficult project if you do not have the right tools. I took it for a spin and I did feel a difference early in the rpms but I didn't really push because I think I still need to tighten the belts a little more. By the way, how much tension should I have on the belts? How do you measure it? I had some squeaks which tells me that I need to tighten them but I'm afraid to over tighten them.

How I got the bolt loose:
- The stock pulley has these holes that bolts go into and are raise so I was wedge something against it.
- I took the bar for my hydraulic jack and wedged it against one of the bolt holes on the pulley. The bolt hole was at about 11 o'clock.
- I laid the passenger side tire on the ground and stuck the other end of the bar into the lug nut hole of my wheel. What was good about this is the tire did not slip and it allowed me to crank the bolt loose. Finally!!!

How I tighten the bolt on the new pulley:
- I took the longer of the old belts and wrapped it around the pulley but folded one side of it and wedge it underneath the belt. This way as I tighten the bolt, I would just need to anchor the other end of the belt and the pulley wouldn't turn.
- I accomplished this by sticking a bar through the tow hook and anchoring the belt on it.
- I sat in front of the car and I held the bar as I carefully pushed my 21" torque wrench with my foot until I heard the long awaited click. "CLICK" Holy shit, I did it!!!

Damn that took me forever to do. It better be worth it. Good luck to you guys that have yet to do yours. I will report back after 1000miles.

akhilleus

06-05-2004, 12:03 PM

good job!! :D

Familia323

06-07-2004, 05:09 PM

i just bought this and need to go get the belts now... So how far is too far when tightening these belts back up, I dont want any squeeking?

Protege_Speed

06-07-2004, 07:01 PM

i just bought this and need to go get the belts now... So how far is too far when tightening these belts back up, I dont want any squeeking?
I have been adding tension little by little if I hear any squeaking. I think I have finally reached the point where it won't squeak. I had the same question so I went to Autozone and checked how to tension the belts in one of the shop manuals. It said that as a rule of thumb, if the distance between the center of one pulley to the other is 7-11 inches, then the flex halfway between them should be 1/4 of an inch. If the distance between the pulleys are 12-16inches, then the flex should be 1/2 inches. Mine is about the there. Hope that helps.

murda79

06-07-2004, 07:23 PM

I just installed my UR pulley this weekend, took about an hour. I love the fact that I only paid $100cdn with a belt used from one of my fellow club members on toprotege.com. I also love the fact that my father is a car god and did most of the install, except when it was time to go under the car, he usually gets me to do the dirty work. He just knows how tight the belt has to be by looking and feeling it, i feel very fortunate. Pulley is great, epspecially for the price i paid.

Familia323

06-07-2004, 09:09 PM

Protege Speed... yeah that did help .. thanks (thumb)

stdntDrvr

06-17-2004, 09:26 AM

i've had mine on for around 14K miles...i LOVE it.

PR5Matt

06-17-2004, 10:15 AM

I ordered one but it was on EXTREME BACKORDER so I am looking for another vendor who stocks them.

stdntDrvr

06-17-2004, 10:18 AM

www.protegegarage.com (http://www.protegegarage.com)

akhilleus

06-17-2004, 01:09 PM

I think they are on backorder from all vendors... try www.tuningdepot.com (http://www.tuningdepot.com) they have OBX pulleys although i have never ordered from them.

dosle

06-17-2004, 01:11 PM

from what i heard from Ken at protegegarage.com they were made in limited numbers and one company bought out alot of the remaining pulleys.

maitai92

06-18-2004, 05:21 PM

Ok guys, I am really sold.. Other than UDP and belt(?) Is there anything I else I need?
Very good info and please keep us posted. BTW, just wondering what kind whp do you get from UDP. Any dynos from anybody?

p5sundevil

06-18-2004, 09:06 PM

well technically it doesnt make an whp, it just frees up HP that is being lost by the engine, basically you are removing rotational mass that was dragging the car before and causing power loss through the drivetrain. UDP's, water and alt pulleys, flywheels all free up more power through this method, they dont "make" power.

What I like about these parts is for NA buildups with bigger cams and a header and stuff your power band moves higher, these things help you keep that low end punch for day to day fun and twisties =)

akhilleus

06-19-2004, 09:05 PM

good point. It definately helps it rev faster.

Subghetto

06-19-2004, 09:26 PM

good point. It definately helps it rev faster.(glare) Yeah it revs a lot quicker than before I have the pulley and I love it the only thing that pisses me off is that unorthodox racing did'nt sell a set of pulleys like they do for other applications, they only sell the UD pulley but something is better than nothing I guess.

p5sundevil

06-19-2004, 09:36 PM

indigo has the other two pulleys for our cars in a set, i believe corksport carries them.

so does shane racing but they are usually a ripoff.

Subghetto

06-19-2004, 09:55 PM

indigo has the other two pulleys for our cars in a set, i believe corksport carries them.

so does shane racing but they are usually a ripoff.
yeah but I'd be more at ease if I got the whole UR set you know not mix and matching.

Minishotglass

06-19-2004, 11:09 PM

what type of decreased performance from the a/c and electrical power can I expect from the installation of ud crank pulley? I know that the reason for a ud crank pulley is to lessen the load on the crank by reducing its contact with the a/c, water pump, alternator etc. but would it come to a point where what is given up is unbearable?

p5sundevil

06-20-2004, 12:17 AM

long as your not running a big system you should be fine, i dont think I will have a problem runninga new HU and an extra 10" sub but just to be safe i will be upgrading to an optima battery and maybe get a voltage gauge to keep an eye on things.

birdy85

06-20-2004, 10:50 PM

hey guys, just wondering what size wrench you guys used to loosen the bolts on the pulleys, to loosen the belts. there are two bolts on the front altenator pulley. i can loosen the front one okay. but the bolt under that pulley, which is running perpendicular to the pulley does not have a size. i have tried every size of wrench on it. can you please tell me what size to use. i treied using an adjustable spanner but it is to hard. cheers

Shades

06-20-2004, 11:33 PM

well, it lightens the load by underdriving the A/C and waterpump, but a lot of the difference comes from the weight difference. The stock pulley is a huge lump of black metal, whereas the UR is a light aluminum alloy. As for loss of power resulting in the non-go-fast system, I do have to turn AC onto 2 before I can really feel it, but so far no probs w/ stereo, turning it up or cranking it loud.

Protege_Speed

06-21-2004, 12:35 AM

If I am not mistaken the front two bolts that you loosen (tensioner & bolt under power steering pulley) is 14mm and the rear two (tensioner and alternator) is 12mm.

hey guys, just wondering what size wrench you guys used to loosen the bolts on the pulleys, to loosen the belts. there are two bolts on the front altenator pulley. i can loosen the front one okay. but the bolt under that pulley, which is running perpendicular to the pulley does not have a size. i have tried every size of wrench on it. can you please tell me what size to use. i treied using an adjustable spanner but it is to hard. cheers

dosle

06-29-2004, 12:13 PM

my pulley is sitting here hanging out, i'm just not sure about tightening the belts, thats all thats keeping me from doing the install. do i need to be a master mechanic to get the belts right?

thanks

Shades

06-29-2004, 03:49 PM

I just did it to where it felt right (the same as they felt before) and when I asked a mechanic later about it, he said it was perfect.

Shades

08-25-2004, 07:59 PM

<<bump>> about 15,000 Miles later, I just got the belts and battery checked. The belts are fine and the battery is cranking better than before I got the pulley (so the alternator isn't being neglected as some have suspected). No problems to report.

MrFoggy

08-26-2004, 03:17 PM

Interesting. I may need to hop on this train.

FYI, Adrenaline Racing is selling it for $150 on clearence still.

Lil Freek

08-26-2004, 03:23 PM

man. i've been looking at this... it's like $160 to have it shipped to canada - that's not bad at all!
now i just need to find $160 :(

DiS

08-26-2004, 06:29 PM

I got mine few months ago, and yea it definetly frees up few hp's from the power transfer. Good to have on NA car, but once I will go with BOOST it will be time to put the stock pulley back on.

Captain KRM P5

09-13-2004, 04:38 AM

Jliao

09-13-2004, 12:58 PM

Where do you get the belt? and how many UR Pulley do I need to order?

xtrememps

09-13-2004, 01:30 PM

Why would you put the stock pulley on? I think turbo magazine put one on a msp...

I got mine few months ago, and yea it definetly frees up few hp's from the power transfer. Good to have on NA car, but once I will go with BOOST it will be time to put the stock pulley back on.

xelderx

09-13-2004, 01:47 PM

Why would you put the stock pulley on? I think turbo magazine put one on a msp...
Stock pulleys are properly balanced for the vibration in the bottom end of the motor. The UDP's are not balanced. In a NA car it doesn't create enough vibration to do any severe damage. In FI cars, though, the bottom end of the motor takes a lot more abuse and has more vibration. In the FS-DE FI motors it can cause premature oil pump failure.

DiS

09-13-2004, 02:29 PM

dmitrik4

09-13-2004, 03:01 PM

how many UR Pulley do I need to order?

one for each crankshaft in your engine. ;)

Installshield 2

09-13-2004, 04:35 PM

Stock pulleys are properly balanced for the vibration in the bottom end of the motor. The UDP's are not balanced. In a NA car it doesn't create enough vibration to do any severe damage. In FI cars, though, the bottom end of the motor takes a lot more abuse and has more vibration. In the FS-DE FI motors it can cause premature oil pump failure.This is a little misleading...UDP's are perfectly balanced...the harmonic resonance stress that affects the crank with a UDP has nothing to do with it being out of balance, and everything to do with it having less mass, or mostly less rotational inertia...

This problem is extremely overhyped though...Crank oscillation is always there...The amount that a stock flywheel and stock drive pulley limit oscillation stress is extremely misunderstood...They barely do...there is still significant stress on the crank with the stock pieces...increasing the output will increase this regardless of if you keep the stock pieces or switch to a lighter dampers...This is the number one reason on why most modern carmakers are using forged cranks in even their small engines recently (the FS didn't always have a forged crank)...heavy flywheels and crank pulleys were not doing a whole lot for oscillation, and cranks were failing well before the rest of the engine...the fact that a lot of engines now utilize forged cranks is the main reason some engines can hold 400whp or more reliably...its not that they kept the heavy stock pieces...its that the crank is extremely strong...

You are correct though...and I am getting off the point...the oscillation stress is far greater with a high torque FI engine compared to a NA engine (higher redlines can cause different types of oscillation though, actually in which it is better to have dampers {thats the shit on the ends of the crank...in this case a flywheel and a drive pulley} that have less rotational inertia)...If you already have a lightweight flywheel and are planning on boosting to 250+whp, I wouldn't recommend that UDP...but if you are staying NA, or boosting less than that power output...you could have both and be perfectly fine...the forged crank is more than up for a slight increase in resonance...

xtrememps

09-13-2004, 04:40 PM

Good info guys! I guess I won't bother with one then since I'd like to have more than 250 hp eventually.

xelderx

09-13-2004, 05:18 PM

This is a little misleading...UDP's are perfectly balanced...the harmonic resonance stress that affects the crank with a UDP has nothing to do with it being out of balance, and everything to do with it having less mass, or mostly less rotational inertia...

This problem is extremely overhyped though...Crank oscillation is always there...The amount that a stock flywheel and stock drive pulley limit oscillation stress is extremely misunderstood...They barely do...there is still significant stress on the crank with the stock pieces...increasing the output will increase this regardless of if you keep the stock pieces or switch to a lighter dampers...This is the number one reason on why most modern carmakers are using forged cranks in even their small engines recently (the FS didn't always have a forged crank)...heavy flywheels and crank pulleys were not doing a whole lot for oscillation, and cranks were failing well before the rest of the engine...the fact that a lot of engines now utilize forged cranks is the main reason some engines can hold 400whp or more reliably...its not that they kept the heavy stock pieces...its that the crank is extremely strong...

You are correct though...and I am getting off the point...the oscillation stress is far greater with a high torque FI engine compared to a NA engine (higher redlines can cause different types of oscillation though, actually in which it is better to have dampers {thats the shit on the ends of the crank...in this case a flywheel and a drive pulley} that have less rotational inertia)...If you already have a lightweight flywheel and are planning on boosting to 250+whp, I wouldn't recommend that UDP...but if you are staying NA, or boosting less than that power output...you could have both and be perfectly fine...the forged crank is more than up for a slight increase in resonance...
Very good detailed info and a much better picture of how it all works together.

Installshield 2

09-13-2004, 11:25 PM

I guess in your defense the stock pieces are said to be "harmonically balanced"...in which case the UDP's are not balanced in that sense...just wanted to clarify that its not that the UDP's spin in an off balanced fasion the way wheels and tires can...UDP's are properly balanced for uniform rotation...

RR-Racing.com

03-07-2005, 02:33 PM

FYI, those you considering getting an underdrive pulley, I'm doing a BB on my pulley for considerably less the UR... .and I guarantee mine is higher quality.

$110 + $10 shipping.... check out the bulk buy forum.

Rafi

Hobbit998

04-30-2005, 01:40 PM

RR-Racing.com

05-01-2005, 01:26 AM

OK. Ordered the UR Pulley and waiting anxiously for it. How much are the Gates belts usually? I noticed a lot of ppl are saying that they feel a noticebly better response. How noticable is it exactly? My PR5 is pretty much stock except with an INJEN intake and TSUEDO exhaust.

Hi, I am just curious mainly because I want to know perhaps there is something that I can do better in order to earn your business. Why would you buy an Unorthodox racing brand pulley and pay 30% more for it when you can can buy my RR-racing pulley (which is better by the way) and save yourself a lot of money...

thanks,

Rafi

melicha8

05-01-2005, 03:53 AM

^^^^Recommended AV^^^^

dosle

05-01-2005, 03:55 AM

i personally am not biased on pulleys when i bought mine 7mo ago... it was just there so i did it. maybe the red finish had a 'bonus' factor to it.

i never installed it, resold. so it doesn't really matter.

DiS

05-01-2005, 07:49 AM

OK. Ordered the UR Pulley and waiting anxiously for it. How much are the Gates belts usually? I noticed a lot of ppl are saying that they feel a noticebly better response. How noticable is it exactly? My PR5 is pretty much stock except with an INJEN intake and TSUEDO exhaust.

Gates belts are recommended for the UR pulley because UR pulley is smaller than stock pulley, and stock belts wont fit (you will have big ass slack with stock belts) thats why you need Gates belts. Not because they will give you a better response.

Hobbit998

05-02-2005, 01:33 AM

Where did you guys get the Gates Belts from? i checked autozone and pepboys... dont' have them.

Dimitrios

05-02-2005, 09:49 AM

Punch in your zip code: http://www.gates.com/automotive/distributors/index.cfm?location_id=539

Pep Boys and Autozone suck ass anyway.

Hobbit998

05-02-2005, 11:30 AM

Punch in your zip code: http://www.gates.com/automotive/distributors/index.cfm?location_id=539

Pep Boys and Autozone suck ass anyway.

Thanks SO Much Dimitrios! (2thumbs)

Hobbit998

05-02-2005, 12:34 PM

Btw, the belts UR says to use are different from the belts the Gates website says to use... UR is K040355 and K050446 versus Gates Website says K040360 and K050459. any difference? which one should i go for? i'm lost

Dimitrios

05-02-2005, 02:23 PM

Does the Gates site have the belts UR is stating? IIRC, the belts should be different than the standard replacements because the outside diameter (OD) of the UR pulley is different (smaller - i.e. underdrive) and you needs shorter belts.

twizyours

05-02-2005, 02:28 PM

First it doesnt realy matter if you us gates or not it is just the size. Ko40355 just means 4 groove belt that is 35 in a half inches long. Ko50446 just means a 5 groove belt that is 44 . 6 inches long. Go to any auto shop and just ask for a 355 k4 belt or 446 k5 belt since most manufactures use those part numbers. Also 360 k4 and 459 k5 are just stock sizes their isnt that much difference in belt size differences. I actually used a 355 k4 for the alternator and same stock belt for power steering just tightened it more. I have the rr racing underdrive pulley that is just the same thing. Oh yeah I forgot I work for autozone.

Dimitrios

05-02-2005, 02:47 PM

lol @ twiz.

Sorry for the comment earlier; I just have always had bad experiences dealing with the folks at Pep Boys and Autozone - some would try to find you muffler bearings if you told them something like that existed and you needed it.

DiS

05-02-2005, 06:11 PM

call UR customer support, they will give you correct part numbers

Hobbit998

05-04-2005, 01:12 AM

Ok, got the right sized belts, just waiting for the pulley to arrive before i install it... it's been 30k miles already so i have new Autolite Double Platinum spark plugs to go with my pulley. (lol2) Still want to know detailed results on the gain from the pulley tho... can anyone describe the changes more? like can an auto transmission burn out by flooring it at a complete stop? or how much lag is reduced before accelaration...? or does it pull more? etc.... (huh)

Lord_Zath

05-04-2005, 01:33 AM

It pulls more at low end. This is due to the engine having to work less in a sense. It seems much happier now for me. It will rev much faster (starting it up from a cold start it shoots up to 2k rpm where it used to slowly rise). The engine just feels as if it's got a load off of it.

Good luck w/the install. Lots of fun times.

Installshield 2

05-04-2005, 02:42 AM

One way to look at these mods that essentially only free up power (such as pulleys or lightened flywheels/axles/wheels etc.) is that the car will behave identically to if you did a massive cut in the overall curb weight...just switching to a 9lb flywheel over the stock one is similar to removing nearly 300lbs from the car for first gear...second gear its like 180lbs or something (there is a calculation, but it is dependant on the gearing...so it is mostly beneficial in lower gears...but you get the point)...

aside from that though, there are excellent increases in throttle response...which makes it much easier for rev matching, and fast shifting overall...