iamhomersimpson

So I want to hear more about the UR pulley.

I have heard good and bad things but I see a lot of the members here use it.

Whats the difference between the underdrive (#020611002) and stock diameter (020611012) one?

I had a horror story a few years ago when my Toyota Matrix XRS engine blew with a UR pulley set (and a lot of other things).

Good, Bad, please let me know what you think. Any hp numbers or quarter mile times would be awesome too

I'm still new here and am sure there are some previous posts around this but am having a hard time finding them.

Karanx7

iTrader: (2)

Underdrive pulley will help remove parasitic HP loss. Your alternator, along with all the other electronic components of your car, can rob your engine of HP. An underdrive pulley will help remove this loss by driving the vehicle accessories slower than the stock pulley. If you get an underdrive pulley, you can need a different belt. It can also cause problems if you have an aftermarket sound system.

Stock diameter pulleys can help by being lighter than the stock pulleys. Less rotating mass can help acceleration.

01tl4tl

the stock pulley weighs approx 10 pounds- thats a lot of rotating mass on the end of the crankshaft

the lightweight pulley weighs approx 1 pound 8-12 ounces!!! under 2 lbs!!

that allows the engine to rev muuuuuuuuch faster- getting to vtec rpm engagement quicker- where the real power is

underdrive is fine up to 600watt stereo, above that the slightly less rpm at alternator wont supply constant power for huge systems when at idle,,traffic,,(assuming normal battery)
In that case the stock size is required
no need for other pulley changes with crank pulley for us

ck UR website for tech info- dyno charts etc,,and bomz another good maker

01tl4tl

only bad I can think of is reduced mpg when used in racer type mode
and those who dont get the bolt back on correct torque spec risk it all~
181 foot pounds iirc..thats a bunch! 100 pounds is not enough

Karanx7

iTrader: (2)

By racer type mode, do you just mean "The Lead Foot"?

Would you estimate 1 hour install time for this job? I don't have a 181 pound foot torque wrench, so I'm hoping the shop install is less than $100.

01tl4tl

you got it,, the lead foot = racer mode

most shops that do honda will do it for 20-60 bucks
30 minutes max for them, very easy job
big compressor tank and heavy duty air tools will make quick work of it
Having the special honda pulley removal tool helps- a good private honda place will have it
look in phone book for smaller ads for auto repair

ask maker of choosen item what belt maker to run with it
some are better with gates- others gatorbacks etc,,
all depends on the angle and type of pulley- internal edge to belt contact

fsttyms1

And are you blaming the blown engine on the pulley set?

sbuswell

UR pulleys are very safe to use. I've had my underdrive crank and alt. pulleys on for over 100k with no issues. I have an 1100wrms system too (but more powerful battery and a 5 farad cap) no issues at all.

mestizoracer310

Sounds like you're saying someone makes the same diameter pulley but in a lighter material..? Am I reading that right or wrong?

Gfaze

UR pulleys are made out of aluminum and are extremely light compared to the stock pulley. I've got a stock size UR pulley on my TL and it's been on for 10K miles with no issues. The car's throttle response is noticeably better afterwards.

princelybug

iTrader: (16)

No issues with mine.

01tl4tl

the lightweight regular size is exactly that,,1.8 pounds of circle cut from a square block/ `billet` of aluminum,, using stock drive diameter

`reg` size are special made for our sponsoring vendor excelerate/xlr8, for those with the giant stereo need
all other makers to my knowledge..are underdrive

the underdrive has smaller diameter and runs the other parts a tick slower- reducing their drag as descibed above
its weight is the thing for making the engne rev faster

Excelerate

iTrader: (1)

Gains are similar whether you install the underdrive or stock diameter pulley. The gains are mostly due to the fact that it's lighter weight.

01tl4tl

they are the same or within a few ounces right Josh?
either way- its more than 8 pounds of 10,, removed--thats an amazing percentage

Imagine going from fat belly 200+ pounds to 160 ripped--same idea,,faster, better performing
or as I look at it- Ive already lost a whole lightweight pulley!!! only 4 to go

iamhomersimpson

I can't 100% blame the pulleys but it was the last mode I installed and after a break in period of about 500 miles my engine blew. I did have other typical bolt-ons but nothing that would have done that kind of damage.

Toyota and the shop blamed the pulleys. They said something about harmonic balance (which Honda's are internal). At the time it was a new part for UR, and it was test install. Free parts from UR, top guys installing it but it def gave me quicker rev to VVTI (toyota's VTEC).

Luckily I worked with Toyota and UR and they replaced my engine for free.

I think I've made my mind up and will be getting the stock size pulley. I already have about 1000W in my car and planning on going to about 3000W by the end of summer.

iamhomersimpson

...follow up question...

So through my research I see that there is a Crank Pulley Set (020611012) and a Pulley Set through XLR8 (040602002).

Thoughts on using these together? Any problems etc? etc?

01tl4tl

only need the crank pulley
adding the others underdrives the accessories too much at idle
a/c function drops,,,

mestizoracer310

Not really planning on going with an insanely huge sound system. Maybe an upgraded shallow mounted sub in the OE location and an external amp..that's about it.

fsttyms1

Unless the pulley wobbled like drunk on a treadmill i highly doubt it was the pulley that killed the motor, especially in 500 miles.

I have had one on for over 200k now. Zero issues.

01tl4tl

he is talking about a test unit for UR-
there could have been some issues with it being the first one--thats why they test them!! and if bad things happen--they cover it..all part of the process