DIY: MI Lightweight Pulley

[jpmck03]

For anyone that's on the fence on how to do this, or just wants some easy printable directions to bring out to the garage/driveway...

[jpmck03]

And the non-printer friendly edition:

Quick Overview

What Is a Lightweight Crank Pulley?
A light weight crank pulley is simply a lightened version of the crank pulley that comes from the factory on a vehicle. On the 1NZ-FE engine, it’s highlighted in red in the illustration below. This pulley is attached to the other three pulleys (to the right on the aforementioned illustration) via a belt.

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Why Do I Want One?
Simply put, it frees up power that the engine was using to keep the heavier OEM pulley spinning. It all comes down to reducing parasitic loss on the engine.
One of the better analogies as to how and why it works is as follows:
“Anything that reduces rotational inertia frees up power. That includes the crank pulley, the flywheel, and your wheels/tires.
“Take a CD in with your fingers around the edge, and spin it back and forth. Now imagine it’s made of steel and much heavier. Harder to spin. Same concept.” 
Introduction
Disclaimer
These instructions are merely a guide. I’m not a mechanic, so please use this as I guide at your own risk.
Suggested Tools
I used the following tools during my install. You may find that other tools my work better for your situation, so feel free to use what is best for you.

½-in. drive teardrop ratchet
⅜-in. drive teardrop ratchet
sockets in ½-in. drive:
19mm socket
sockets in ⅜-in. drive:
12mm socket
14mm socket
Torque wrench
floor jack
jack stand
chock or block of wood
WD-40 (optional)
work gloves (optional, but really suggested)


Installation
Time Required
30 – 45 minutes.
Installation
Lifting and Panel Removal
First thing’s first: park your car on a nice even area, and make sure to engage the parking brake. You are going to need to jack up the car on the front passenger side, so chock the rear driver’s side wheel and jack up the car. Make sure to use jack stands for your safety!

After the car has been lifted, remove your front passenger’s side wheel and put it aside. Inside the wheel well, you will see a panel that has to be removed (shown in orange in the photo below).

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There are six bolts that have to be removed to take off this panel. Once you remove this panel, you will be able to see the OEM crank pulley (shown in red in the photo below).

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Alternator Loosening and Belt Removal
In order to remove the crank pulley, the accessory belt must be loosened and moved out of the way. To do this, the alternator must be loosened and moved to release tension on the belt. Recall the illustration on page 1. There are two bolts which must be loosened in order to move the alternator which are both highlighted in yellow. Before loosening these two bolts, it is handy to mark the location of the top bolt on the bracket. If you are using a smaller wrench, it may be helpful to use a small piece of pipe to extend the ratchet. Loosen both bolts and then gently press the alternator back towards the engine. The end result of this step is shown in the photo to the right. This will release tension on the belt, and allow it to be moved out of the way.

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Pulley Removal and Replacement
There are a number of different ways to remove the pulley. For this guide, the simple hand tools method will be used. To remove the pulley, have someone hold the pulley in place while you loosen the bolt on the pulley. This can be achieved with several methods: a.) wedge a screwdriver between the pulley and the engine block (don’t use this method on the lightweight pulley!), b) have someone hold the pulley in place by wrapping a shop rag through the pulley, or c) tie a rope between the pulley and the frame to hold it in place.

Using a breaker bar (or impact gun, if you have one) and 19mm socket, break the bolt holding the pulley in place loose. Once it has broken free, finger loosen the bolt, while holding the pulley in place. Slowly remove the pulley being mindful of the pin that is used to align the pulley!
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Reassembly
Now that you have removed the OEM pulley, you can begin the reassembly process. Reapply your new pulley, ensuring that the pin is lined up and everything is snug. Finger tighten the bolt until tight, then using a torque wrench, tighten the bolt to 95 ft•lbf. Then, run the pulley back around the crank pulley.

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Move the alternator back to its original position, tightening the top bolt first, to hold in place, followed by the bottom bolt. While the access panel is still open, give the alternator a few spins to ensure that the belt is properly seated on the pulley. At this time you could start up the car to make sure everything is running smoothly before finishing up.

Replace the wheel well panel, noting that the 2 bolts with thinner threads go into the top portion of the panel nearest the pulley. Put your wheel back on and lower the car.

Functions Check
To ensure that everything was done correctly, check the following:

Before starting the car, look to see if the belts are properly aligned and seated on each pulley.
With the car running, check to see if the belts are still aligned and properly seated on each pulley, and listen for any noises.
If there are any squeals or noises coming from the belts, check to see if the belts are properly tightened.

[ricepower]

Excellent DIY writeup!:w00t:

[BEEF]

I am doing this, this evening.

your write-ups are really good. I really like the color coding that you do. How do you do that? is it in paint? photoshop? GIMP?

[jpmck03]

I am doing this, this evening.

your write-ups are really good. I really like the color coding that you do. How do you do that? is it in paint? photoshop? GIMP?

Thanks!

Let us know how it works out. (There's a thread here that you just got it, amiright?)

I used Paint.NET, which is similar to GIMP and/or Photoshop, but Windows only.

[BEEF]

I've actually been meaning to ask. I saw the one you did also on the under hood short shifter. Part of it was so that I could tag the thread and just go to user CP and find this thread quickly when I went to do the install (shameful, I know).

The install went without a hitch. I didn't have a torque wrench so I had to wait until my buddy could help. He has a huge one (torque wrench, that is). All in all, not too bad.

http://i1306.photobucket.com/albums/s580/ahazelwood7054/torquewrench_zps8aa09235.jpg

[TOLMACH]

Wow,, that is one big torque wrench!

[dobbiedoo]

How much HP does it free up, and where do you et one?

Thanks

[DJYojimbo]

It doesn't really add HP but it seems like acceleration is a lot better. I just got it installed yesterday with my tanabe exhaust and when i just step on the gas a little bit it pulls and its awsome! here's the link for the pulley! http://shop.microimageonline.com/MI-Lightweight-Crank-Pulley-MI-LWCP-Yaris.htm

[cali yaris]

Wow,, that is one big torque wrench!

No kidding!

i just step on the gas a little bit it pulls and its awsome!

Correct, the lighter pulley won't add actual horsepower, but by using less energy to spin it, more power is transferred to the wheels, where you feel it.

[iceage]

Hey beef,

After installing the pulley, do you notice any squeaky sounds?

[BEEF]

I did have to pull the alternator back farther than the mark that I made for realignment but I did not notice any squeaking. I figure my belt had streched some over time (30,000 miles but 4-5 years old on original belt) but it does not squeak. I was concerned about that as others had said that it makes a squeaking noise.

So far, so good. No weird noises or hiccups.

[why?]

most belts will need to be adjusted after install. Mine was horrid. After adjusting it was perfect.

[NaviLupets]

does the new lighter weight pulley do damage because it absorbs less vibration?

[jRoss]

Awesome write up! I planned on doing this mod and installing it myself. Thanks a ton!

[esse10]

does this give ya anymore MPG ? anybody who has already done it confirm or seen any difference in MPG?

[jpmck03]

does this give ya anymore MPG ? anybody who has already done it confirm or seen any difference in MPG?

Yes, it can. (http://yarisworld.com/forums/showpost.php?p=668393&postcount=24)

Depends on how you drive though, and a lot of other factors, I'm sure.

[Golddeenoh]

does the new lighter weight pulley do damage because it absorbs less vibration?

no, 4 cylinder engines are balanced vertically and don't have the need for a harmonic balancer like many "V" type engines. it wont hurt your engine unless you install it incorrectly.

[jRoss]

Wow! MI raised the price...5 days before I make my order. Awesome! Now it will be at least 3 weeks before I can afford it!

[BEEF]

you may want to email them or call them. if it really was that you missed that window by that short of a time, they may work with you.

you never know if you don't try.

[cali yaris]

Looks like our sales price timed out (I have to enter dates into the cart for discounts). I'll look into it.

[marcus]

just curious how much was the sale price??

[BEEF]

I thought it was $139 or something....but now you can get black or red. Mine is just silver. I got mine on a black friday deal so it was a touch less. I then waited like 4 months to put it on. That sucked.

[NaviLupets]

how long have u had your pulley installed for? cuz i have been reading a bunch of articles and it says that it will damage your engine. trust i would love to buy that part and install it but I'm looking for more evidence that it wont.

[tk-421]

Things aren't always what they seem. I've had the NST pulley installed for 5 years with no issues, and a big difference in throttle response. Don't believe me? Pretty cheap to try it out for yourself. :thumbsup:

(And pretty straightforward too, thanks to jpmck03) :respekt:

[jpmck03]

how long have u had your pulley installed for? cuz i have been reading a bunch of articles and it says that it will damage your engine. trust i would love to buy that part and install it but I'm looking for more evidence that it wont.

9 months, no problems whatsoever. Only issues I've heard about it is getting the belt at the right tension after installing it (happened to me, too). Not a biggie, the belt squeaks a little and you tighten it up!

NST made a similar version of this pulley back in the day, people have run them for tens of thousands of miles without any issues. The MI one is a bit better from a build point of view, so you should be good to go for the life of your Yaris.

Edit: What tk-421 (http://yarisworld.com/forums/member.php?u=2646) said!

[Astroman]

90k miles, improved engine response, less gear hunting in the automatic when climbing hills, improved MPG and ZERO issues. I'm using the nst version and can say without a doubt a very worthwhile and noticeable modification. Laws of physics apply here, less rotational mass!

[marcus]

now with all this discussion i now have the urge to get one.. awaiting for sale price garm.;)

[Astroman]

Alright I let this go on long enough and cleaned it up. If the newb can't understand the simple laws of physics and rotational mass (and that you can't even see the crank pulley, so there goes the decoration theory) there is no use arguing. This is a simple DIY write up on installing a new pulley, not a debate of opinion which ignores physics, science, and facts. :rolleyes:

[cali yaris]

awaiting for sale price garm.;)

It's baaack.... :smile:

[jRoss]

My brother and I had this argument for a few hours today. My point was that it would help me merge onto the highway a bit easier, especially with all the uphill on ramps around here. He argued it would only help with high rpms, like 5k+... Idk I just think its worth a try, since I'm revving high to merge anyway. Plus I just like working on cars and fresh car parts ;)

[jRoss]

It's baaack.... :smile:

My man! (Denzel Washington voice)

[marcus]

It's baaack.... :smile:

sweet.. hope this will be running for atleast 2 weeks..just curious if you still sell the projector lense kits i dont need hids just the proj lense kit and how much.

[cali yaris]

^ If you mean to retrofit your headlights, it's a kit-in-a-box and only sold that way.

[marcus]

^ If you mean to retrofit your headlights, it's a kit-in-a-box and only sold that way.

pm'ed..

[CharlieBravo]

Just installed mine, but quick question:

Do you need to reset the ECM after the install? I'm thinking yea.......

[Jeff@MicroImage]

Just installed mine, but quick question:

Do you need to reset the ECM after the install? I'm thinking yea.......

No need to reset the ECM but you're welcome to do so if you like.