Lightweight pulleys: reliability & smoothness - Toyota Yaris Forums

MyBlueYar · 03-14-2023, 01:03 AM

Hello all you Yaris enthusiasts. I'm a recently new Yaris owner, having bought an '09 Yaris hatchback. I've enjoyed the car thoroughly up until now, but am just now dipping my toes into the waters of the vast depth of knowledge this site offers.

My first upgrade was ditching the stock steelies in favor of a set of lightweight wheels from a Mini Cooper. I was lucky enough to find a set with new tires already on them, and the guy gave me a very good deal in the process. The wheels were the 5 star spooler wheels (R100 I believe), and if the online published numbers are to be believed, they are 13.7 lbs each, an improvement over the original steelies. The vast improvement in the interior sound levels just from the tire change was very noticeable.

I've scoured this site about NST lightweight pulleys (and to an extent MI as well) in my search for my next mod. Mind you, I'm probably one of the few people who is mostly content with the stock hp of our mighty Yaris. While I think another 5-10 hp would be ideal, I did not go into this purchase with high expectations in that regard.

On NST's website, they address one of the most common concerns about engine balancing (internal vs external) and dispel the myth of lightweight pulleys destroying the modern day engine that is internally balanced.

My question to those of you who have already modded your Yaris with one or more of their lightweight pulleys is this: I'm not after crazy hp gains with a simple pulley upgrade, that much I am realistic about. My bigger goal with this car and the incremental improvements is to make it somewhat quieter, and if possible, smoother in its daily operation.

So for those of you with NST pulleys installed, how did it affect the engine smoothness in terms of day to day driving? And secondly, I believe I read a post about someone who installed the crank pulley on their car, and found it made it a bit more jerky in taking off. What was your experience?

Any feedback on these lightweight pulleys from those of you who have a before & after would be greatly appreciated. Thanks in advance -

mitch9521 · 03-14-2023, 07:26 AM

I have the NST crank pulley on my 2014 and it makes the engine more responsive yes, but you lose rotating inertia which can make it annoying to drive in traffic if you have a manual.

Especially so with the annoyingly touchy but somehow not touchy E-throttle mapping the Yaris has. I'm actually considering going back to the stock pulley to regain some of that inertia back and make it easier to be smooth when taking off but I threw out my stock pulley like an idiot so now I have to go pillage one from the junkyard

remcafee · 03-14-2023, 11:44 PM

remember that it has nothing to do with balancing, it has to do with harmonics, it does not have any harmonic dapening compared to the stock pulley which has rubber molded into it to dampen harmonics created from inertia, harmonic dampening is important to reduce wear on crankshaft main bearings, as without harmonic dapening the harmonics dont get cancelled out and transfer all through the crankshaft

MyBlueYar · 03-15-2023, 12:04 AM

Quote:

Originally Posted by remcafee

remember that it has nothing to do with balancing, it has to do with harmonics, it does not have any harmonic dapening compared to the stock pulley which has rubber molded into it to dampen harmonics created from inertia, harmonic dampening is important to reduce wear on crankshaft main bearings, as without harmonic dapening the harmonics dont get cancelled out and transfer all through the crankshaft

REM - I do realize what you say about harmonic dampening, and have read several posts on here that essentially agree with you. My loose paraphrase of NST's website that takes the opposite position was simply that, positing that according to them, engine balancing is apparently not a problem in terms of long term engine/bearing reliability.

I don't have an official position myself yet, as there are two sides that take completely opposite views, some even coming from the camp of automotive engineers.

But I wanted to do my due diligence before jumping at the first chance of putting an underweight pulley(s) on my newly purchased Yaris. For that, thank you very much for your input and giving me additional food for thought.

sh0rtlife · 03-15-2023, 06:21 AM

your half right

the harmonic aspect of it can and will remove excess noise and "jitter" from the crank...the same has been done on some engines with a counter shaft..which is escentialy a second crankshaft spining nothing but weights

think of it more as a spinning chunk of dyno mat for the "feel" of the engine

remcafee · 03-16-2023, 02:58 PM

most likely your engine will be fine with the nst pulley, there is no doubt that it puts more wear on the crankshaft though

MyBlueYar · 03-16-2023, 05:29 PM

https://www.nonstoptuning.co/blog/li...od-bad-depends

Food for thought pertaining to lightweight pulleys.

Neinris · 03-17-2023, 10:30 AM

Quote:

Originally Posted by mitch9521

I have the NST crank pulley on my 2014 and it makes the engine more responsive yes, but you lose rotating inertia which can make it annoying to drive in traffic if you have a manual.

Especially so with the annoyingly touchy but somehow not touchy E-throttle mapping the Yaris has. I'm actually considering going back to the stock pulley to regain some of that inertia back and make it easier to be smooth when taking off but I threw out my stock pulley like an idiot so now I have to go pillage one from the junkyard

Maybe go with something that's not super light, something that just bring it half the weight maybe?

https://www.heeltoeauto.com/alutec-p...etc-cp-18.html

https://www.youtube.com/watch?v=Vo2g7544Fz8

mitch9521 · 03-17-2023, 08:28 PM

Quote:

Originally Posted by Neinris

Maybe go with something that's not super light, something that just bring it half the weight maybe?

https://www.heeltoeauto.com/alutec-p...etc-cp-18.html

https://www.youtube.com/watch?v=Vo2g7544Fz8

I didn't realize someone other than NST still made lightweight pullies for the 1NZ. Neat

Compeer · 03-18-2023, 01:28 AM

Quote:

Originally Posted by mitch9521

I didn't realize someone other than NST still made lightweight pullies for the 1NZ. Neat

Theres one on Ebay and then theres also Works enginnering got them linked in the discord.

Neinris · 03-18-2023, 02:06 PM

Quote:

Originally Posted by Compeer

Theres one on Ebay and then theres also Works enginnering got them linked in the discord.

Way to promote the discord channel...

sh0rtlife · 03-19-2023, 02:40 PM

i use my 58 ford as a solid reference on "harmonic balancer removal"..its an internally balance 312 police interceptor V8..one day it simply let the harmonic balance section go off the engine at idle so no harm no foul...i drove it like that for a while and yes the performance gains from losing the weight was pretty big, but the "harmonic vibration" from not having it was weird and could be compared to the way an exhaust drone works...it was most noticeable at idle as a "wave" of a harmonic vibration would just ripple thru the car...it was gone off idle but if you held a steady rpm for more than 5 mins youd find it again

dont get me wrong v8 5.1 vs I4 1.5, but the principle remains the same...also mind you its not very bad and the way the yaris engine mounts work they may soak up some of it as well....

03-14-2023, 01:03 AM	#1
MyBlueYar Drives: 2009 Toyota Yaris Join Date: Feb 2023 Location: Seattle Posts: 22	Lightweight pulleys: reliability & smoothness Hello all you Yaris enthusiasts. I'm a recently new Yaris owner, having bought an '09 Yaris hatchback. I've enjoyed the car thoroughly up until now, but am just now dipping my toes into the waters of the vast depth of knowledge this site offers. My first upgrade was ditching the stock steelies in favor of a set of lightweight wheels from a Mini Cooper. I was lucky enough to find a set with new tires already on them, and the guy gave me a very good deal in the process. The wheels were the 5 star spooler wheels (R100 I believe), and if the online published numbers are to be believed, they are 13.7 lbs each, an improvement over the original steelies. The vast improvement in the interior sound levels just from the tire change was very noticeable. I've scoured this site about NST lightweight pulleys (and to an extent MI as well) in my search for my next mod. Mind you, I'm probably one of the few people who is mostly content with the stock hp of our mighty Yaris. While I think another 5-10 hp would be ideal, I did not go into this purchase with high expectations in that regard. On NST's website, they address one of the most common concerns about engine balancing (internal vs external) and dispel the myth of lightweight pulleys destroying the modern day engine that is internally balanced. My question to those of you who have already modded your Yaris with one or more of their lightweight pulleys is this: I'm not after crazy hp gains with a simple pulley upgrade, that much I am realistic about. My bigger goal with this car and the incremental improvements is to make it somewhat quieter, and if possible, smoother in its daily operation. So for those of you with NST pulleys installed, how did it affect the engine smoothness in terms of day to day driving? And secondly, I believe I read a post about someone who installed the crank pulley on their car, and found it made it a bit more jerky in taking off. What was your experience? Any feedback on these lightweight pulleys from those of you who have a before & after would be greatly appreciated. Thanks in advance -

03-14-2023, 07:26 AM	#2
mitch9521 Gen 3 > Gen 2 Drives: NCP131, F-150 Join Date: Jul 2019 Location: Red Deer, AB Posts: 497	I have the NST crank pulley on my 2014 and it makes the engine more responsive yes, but you lose rotating inertia which can make it annoying to drive in traffic if you have a manual. Especially so with the annoyingly touchy but somehow not touchy E-throttle mapping the Yaris has. I'm actually considering going back to the stock pulley to regain some of that inertia back and make it easier to be smooth when taking off but I threw out my stock pulley like an idiot so now I have to go pillage one from the junkyard __________________ 2014 NCP131 5 Speed 2007 F150 4.2L 5 Speed 2013 Rav4 LE AWD Autotragic - Wife's

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Lightweight crank pulleys?	ltwargssf	Performance Modifications	8	02-25-2023 07:43 PM
Pulleys interchangeable?	Swing	Performance Modifications	16	05-07-2014 01:16 PM
Concerns about pulley's	Black_griffin6	Performance Modifications	35	02-04-2012 12:05 PM
Pulleys, pulleys, pulleys!	Deltasix	Performance Modifications	15	03-21-2009 11:10 PM
NST lightweight pulleys kit	t0m4s	Central and South America	23	02-17-2009 04:10 AM

03-14-2023, 11:44 PM	#3
remcafee Drives: 2007 Toyota Yaris 3 door Join Date: Sep 2018 Location: Arizona Posts: 403	remember that it has nothing to do with balancing, it has to do with harmonics, it does not have any harmonic dapening compared to the stock pulley which has rubber molded into it to dampen harmonics created from inertia, harmonic dampening is important to reduce wear on crankshaft main bearings, as without harmonic dapening the harmonics dont get cancelled out and transfer all through the crankshaft

03-15-2023, 06:21 AM	#5
sh0rtlife Drives: 2007 5dr canadian import Join Date: Dec 2016 Location: pacific north WET Posts: 1,025	your half right the harmonic aspect of it can and will remove excess noise and "jitter" from the crank...the same has been done on some engines with a counter shaft..which is escentialy a second crankshaft spining nothing but weights think of it more as a spinning chunk of dyno mat for the "feel" of the engine

03-16-2023, 02:58 PM	#6
remcafee Drives: 2007 Toyota Yaris 3 door Join Date: Sep 2018 Location: Arizona Posts: 403	most likely your engine will be fine with the nst pulley, there is no doubt that it puts more wear on the crankshaft though

03-16-2023, 05:29 PM	#7
MyBlueYar Drives: 2009 Toyota Yaris Join Date: Feb 2023 Location: Seattle Posts: 22	https://www.nonstoptuning.co/blog/li...od-bad-depends Food for thought pertaining to lightweight pulleys.

03-19-2023, 02:40 PM	#12
sh0rtlife Drives: 2007 5dr canadian import Join Date: Dec 2016 Location: pacific north WET Posts: 1,025	i use my 58 ford as a solid reference on "harmonic balancer removal"..its an internally balance 312 police interceptor V8..one day it simply let the harmonic balance section go off the engine at idle so no harm no foul...i drove it like that for a while and yes the performance gains from losing the weight was pretty big, but the "harmonic vibration" from not having it was weird and could be compared to the way an exhaust drone works...it was most noticeable at idle as a "wave" of a harmonic vibration would just ripple thru the car...it was gone off idle but if you held a steady rpm for more than 5 mins youd find it again dont get me wrong v8 5.1 vs I4 1.5, but the principle remains the same...also mind you its not very bad and the way the yaris engine mounts work they may soak up some of it as well....