I'm a proud new owner of a 2006 model tC and thus far I simply love the car. I've been reading a lot about options for performance improvements and the thing that seems an ideal starting point is the Crank pulley. However before I upgrade to a lighter unit I have a question....

On a lot of older cars the pulley on the crank is attached to a "harmonic balancer", which also served to stiffle vibration that can cause engine wear. My question is that if I install a lighter crank pulley to improve throttle response, am I shooting myself in the foot by creating more potential for engine wear?

I realize that we've come a long way in technology and engine building. I just want to ensure that I'll be able to drive and enjoy my car for a long time.

Thanks in advance for any input or advice.

Cheers.

 

Hey congrats on the new car.

As for the pulley I have heard of a handfull of people having problems and then many more not having problems. I myslef have been driving on it over 5k and no problems and read on here of people well over 75k no problems.

its just like any part, any part can cause problems whether installed worng or bad manufactured, and can be great if done right or a good part.

Let me know if you need anything for you car.

Thanks and congrats again on the car!

Ryan

 

actually, things havent changed too much recently. On my previous car, a 02 Civic, the crank pulley was attached to the harmonic damper/balancer. I am not sure if the tC has an internal (within the block) balancer...... I suggest either wait for more posts or wait longer to get it b/c the aftermarket hasnt really had much experience with the 2AZ.

 

http://www.yoursciontc.com/forums/in...opic=6923&st=0
here is a little info on the pulleys, hope it helps you decide. Personally i would vote against it due to the dangers of engine damage...doesn't always happen, but it happens a lot

 

thats some great information! Thanks!

oh, 1 last thing about the crank pulley from what I read on the Civic board...... some ppl experienced problems within a few days. Perhaps underdrive pulleys is the way to go?

 

If you hadn't have posted it, I would've. Definite reading material for anyone thinking about this mod.

 

make sure and follow the other links over there in that thread (dinan, ati, etc) very good info there as well.

 

Actually, a lightened flywheel would be a better idea...it removes about the same amount of weight and has 0 - few problematic experiences...at least that have been/not been posted

 

It removes FAR more weight. You can only save a few ounces with the pulley while the flywheel saves a few pounds.

 

Yep, a few lbs on a larger rotating mass. Much more effect.

 

understood, I mentioned underdrive pulleys for those that MUST get pulleys. I have only been in 1 car with a light weight flywheel....... I'm interested in purchasing 1 myself somewhere down the line.

 

glad i could be of assistance...whatever you decide on, hope u enjoy it!

 

Bah... screw the warnings and go for it... Not an issue in the world for me... and MANY other Scion guys and the miles are continueing to count... just a look at the stock pulley shows the "Harmonic Balancer" is pretty crappy in the first place, and the rubber is crispy after a good amount of engine use...

But this is ALL dead horse beating... I still run them and am in contact with tons of other guys who do as well, and nothing bad yet... we'll see in 80,000 miles...

 

There is no harmonic balancer on the stock pulley, so that isnt an issue. There is a damper. Two separate systems (we are internally balanced with a vibration damper built into the pulley). Engine life will positively be affected in some way, however subtle or obvious it may be. There really is no arguing the physics there. But like you said, dead horse, the info, arguments and links have been posted.

 

i vote we lock this to avoid another pulley debate...i disagree with some opinions, and i agree with some, but we dont need another one of those.....

 

I agree. I myself should have known better than to post anything about it. The links have been posted so we should not start another one.

 

I have used NST pulleys on several cars over the past few years. From high horsepower turbo Toyotas to basic bolt on n/a hondas. I have never had any issues of any kind. I have seen more power and much better throttle response as a result.

There are a few very passionate people on the internet who will go to great lenghts to prove to you that your motor will break into pieces after you install a crank pulley. The reasoning is the following:

The stock crank pulley has a "rubber band" sandwiched inside the pulley that is supposed to help as a harmonic dampner. Meaning that it will help take some vibrations off the crank. Aftermarket pulleys like the ones made by NST, UR, etc. do not have this piece of rubber built into their pulleys because the engineering required would significantly increase the MSRP, meaning you would have to pay $350 for a crank pulley instead of $125. These vibrations are theoretically bad for the motor and increased vibrations could theoretically lead to premature engine failure over a long period of time.

Those against aftermarket crank pulleys always say that they had a friend of a friend of a friend who put lots of different mods on his car and blew up the motor, so it must have been caused by the crank pulley! They give you theories and arguments based on physics and mathematics, but very little concrete real world proof. There are no actual real world tests that have shown real crank failure due to pulleys.

One would have to put up a 100% bone stock motor vs another motor with only a crank pulley of this type installed and run both to death to see which would die faster. That would be the only real way to prove their theories, and none of them have done this!

Even the most passionate of those who are against crank pulleys agree that even if these vibrations are bad, the effects will not be seen for a very long time. We are talking about 150,000 or more miles in the future.

Bottom line; there are many pulley owners who have owned pulleys for a long time and have been satisfied (like me) and there are others who have never owned or even seen an aftermarket pulley in person and tell you to stay away from them because of what they have read on the internet. And since they read it on the internet, it must be true!

Here is a link for you to a thread here on SL where people have been discussing their first hand experience with pulleys on the tC. Take a look for yourself and see how many have blown their engines so far:
https://www.scionlife.com/forums/viewtopic.php?t=122725

 

As mentioned, all of the arguments and links (to companies that actually put a LOT of time and experience behind this) are posted here and in the link over to ystc. Lets leave it at that. There are plenty of places that have this argument covered.

 

I can attest to years and years of use with no ill or side effects from Pulleys in general. I have used NST for around 3-4 years now logging massive milage on motors running underdrive pulleys, some of which turning 4Krpm+ over our low revving 2az engine.

I can say I have NEVER had an issues with any pulleys I have run. Nothing but better throttle responce.

If you go on the logic of OMG it is gonna cause somthing eventually to my engine, then leave it bone stock. Any modification in any way shape or form if it alters anything at all can affect your engine over a very very long period of time in a pos or neg way, you never know... Chances are your going to have this car mabey 100K miles, heck mabey 200K. I doubt you will ever have an issue related to installing an UD pulley. In fact you will get longer accesory life. That is also just simple physics I use a lightweight crank pulley on my baby as well. If I felt there was even a nominal chance of an issue, it would not be on my car and I have been building engines and cars a long time

Last note, a tensioned belt usually dampens more frequency than a pulley with such a thin rubber isolator such as the 2az's. We also have twin blance shafts which helps.

My reccomendation is Mod your car the way you want it, keep a solid service schedual and she will last an increadibly LONG time weather you install a ud pulley, header, intake..... you get the idea. Just do not beat the snot out of it 24-7 as some do and then complain of anything happens.

 

i've been running NST pulleys on my car for over 20k miles. no problems since. pulleys are a perfect way to add some hp and gain throttle response.