Alu crank pulley.. are they good?

[gon]

from what i have heard Toyota use to calibrate all the items independently ( crank , flywheel, etc. ) so as long as your new pulley is also balanced you shouldn't have a problem ....

ideally you should when installing the pulley grab your crank , flywheel etc and bring them to a shop to balance them all together.......

don't think it's what's gonna break you engine though .... and if your going to balance it all you will never need an harmonic .........

[jondee86]

Hmmmm..... crankshaft harmonics are produced by the firing stroke
impulses and compression forces. Balancing the components, together
or separately, will not reduce the need for a harmonic balancer.

The factory use them for a good reason. And like any other modification
that you do to your engine, there will be a price to be paid for the small
increase in response that you gain by deleting the balancer.

Here is an article on the subject of harmonic balancers, or harmonic
dampers if we are to describe them correctly...

http://www.dinancars.com/bmw/technial-in...nic-damper

It is written by someone who specialises in BMW's, but the information
applies to any vehicle factory fitted with a harmonic damper.

Cheers... jondee86

[Allexz]

yeah that worked well

[NonStopTuning]

This one deserves an entire book, but here goes...

Q. Will NST Pulleys lead to premature engine failure?

I cover this topic at least several times a month but I don't mind, I understand that your cars are a very large investment for all of you and I prefer that you be intelligent and informed about all your modifications. So here we go again... Please take a few minutes to read everything I have posted here, as I worked hard on trying to give you a good explanation on the topic...

In the past many engines were externally balanced. There was an external balancer attached to the outside of the engine, on the crank snout, used to balance the engine externally. The crank pulley in such engines would then be attached to this balancer. Removal of this balancer is a bad idea. These balancers were most often used on large ( 6 to 8 ) V shaped engines of the domestic muscle car era.

Take a look at any modern (1980s and beyond) Honda, Toyota, Nissan, or other japanese inline 4 and you will find no such balancer. These engines are all internally balanced, and this process has improved even further since the late 1990s. So the topic of a BALANCER does not apply here.

What you will find on many modern engines is a harmonic damper. This is a small rubber band, litterally less than 2mm, less than 1/8th of an inch, thick that is built into the crank pulley. OEM crank pulleys are often called DAMPERS. Try placing an order for a crank pulley at your dealer and your invoice will read damper. This rubber is used to absorb something called NVH, noise/vibration/harshness. Suffice it to say, this rubber is actually not very good at performing its intended purpose after as little as a few thousand miles. What happens to rubber after a couple years of humidity, weather, snow, rain, etc? It often becomes brittle, hard, and crunchy. Can something with these properties actually absorb vibrations very well?

Many many NST customers, including people on your own forums, have reported smoother running engines with NST pulleys. Especially at idle. How is this possible if the rubber is such a vital and super important piece? Perhaps the rubber is not as important as it is cracked up to be?


Furthermore....


On the topic of the rubber damper, engine vibrations, or possible threats resulting from elimination of this rubber piece...

On a relatively understressed near stock motor with bolt ons or low amounts of boost like what most of the people on this forum probably run, a solid pulley will not have any life threatening consequences.

The engineering reasons are that most modern engines have a short, strong crank with, a relatively high natural frequency. The dangerous second harmonic that can cause damage occurs at an rpm that this sort of engine will never see, in the area near 10,000 rpm. Even the stock damper is not tuned for attenuation at this sort of rpm so the argument is somewhat of a moot point.

Now weak engines that are pushing the limit with LOTS of revs, wimpy cranks, super long strokes, lots of boost and dwelling in the upper rpm ranges for long periods of time can benefit from a damper designed to deal with this sort of operation but our engine is not like this, and probably very few people with this motor on this forum push the envelope that hard. How many 600HP, 12,000RPM motors do we have on these forums?

As far as I can tell, our engine has a strong and stiff bottom end that is well built for our intended use. It has an internally balanced crankshaft which is less like to break due to torsional vibration.

There are a lot of Honda, Toyota, and Nissan guys who use underdrive crank pulleys in road racing series like NASA or SCCA. Road racing is much more punishing on an engine than other motorsports. The engine is subjected to run times lasting roughly 30 minutes with the engine always in the upper ranges of its rpm limit. One race weekend is the equivalent of hundreds of 1/4 mile passes. These guys would not use NST pulleys if they were not reliable.

NST sponsors the first ever wheel to wheel Scion tC NASA Road Race car. The same car is also very competitive in the Grand Am series and has factory backing from Toyota, Scion, and TRD. This car has been using pulleys from NST with great results since day one.

NST has sponsored several drift cars participating in the professional US drift series, Fromula Drift. Our cars also compete in the D1 Grand Prix USA, and have campaigned the NOPI Drift Series. To make things better, NST products are also used in autocross, time attack, and drag cars. These cars have been using NST pulleys with no issues of any kind for the past few seasons.

We could go on and on...

Is a solid crank pulley harmless to all engines? No it is not. As I said... small, super high reving engines, when modified way past the simple bolt on stages may have problems. These engines reach critcal harmonics, past the 10,000 rpm range, an rpm only reached by certain RACE engines.

A mildly modded inline six will most likely be fine but one subjected to high rpm for long periods of time (90% of its life) with lots of boost and a redline near/above 10,000 rpm will probably suffer. In this case , the stock balancer/damper is also not adequate.

Some of the older American V8 engines are externally balanced and it is critical not to use a solid hub pulley not designed for these applications, or damage to the engine could result. You will not find solid NST pulleys on our website for such engines.

Our engines and most around here do not fall into the above categories. Your engines will not blow up and die, or have a reduced life, in street and even racing use with these parts.

I would bet that every "expert" that tells you otherwise has little personal, practical, real world experience with the subject; as it applies in your case.

Again, I understand that your cars are a very large investment and that you depend on them as your daily means of transportation, so I do not take your questions personally. But please, do your homework and you will find thousands of happy NST customers, all of whom have had nothing but positive experiences with our products.

[NonStopTuning]

To continue...


I can share the following real world info with you based on my personal experiences during my past decade of drag racing, road racing, and professional drifting...


Dan Gardner's NASA road racing Scion tC, backed by Scion, Toyota Racing Development, and NST has never had any issues while using a full array of NST products over the past few years...




NonStopTuning's turbocharged S13 drift car competed for several seasons in the Formula Drift Pro-AM and other drift series and never had any crank problems...




Tommy Suell's Formula Drift AE86 drift car was consistently ran at redline for several seasons and was putting down twice as much power as it did when the motor was in stock trim, and it never had any crank/bearing problems. Those of you who are familiar with professional drifting know that these cars sit at the rev-limiter the entire time they are on track.




NonStopTuning's custom turbocharged 4AGE 2009 D1GP USA drift car ran the entire season on the same engine, using the entire catalog of NST products for the 4AG, and never had any engine problems of any kind related to NST pulleys. Again, those of you who are familiar with professional drifting know that these cars sit at the rev-limiter the entire time they are on track.




Joshua Steel's 2009 D1GP USA 350Z has been on the same engine, using NST pulleys for the past two seasons. No cases of engine, bearing, or crank failure.



Joshua Steel's new 2010 car has also been using NST pulleys with no issues of any kind.





Not all aluminum pulleys are created the same, and no other pulley is an NST pulley.

[NonStopTuning]

In addition, there are dozens of comprehensive NST threads where thousands of NST customer have posted their firsthand, real world, daily/track, experiences with our products on Hondas, Nissans, Toyotas, Scions, etc.

Theories are a great place to start, positive real world reviews from thousands of real world users is worth more in some peoples' books...

http://www.86garage.com
http://www.club4ag.com
http://www.yarisworld.com

http://www.scionlife.com
http://www.microimageonline.com
http://www.xr-underground.com

http://www.tercelonline.com
http://www.solaraguy.com
http://www.scikotics.com

http://www.8thcivic.com
http://www.tsxclub.com
http://www.fabricatedmotorsports.com

http://www.houston240sx.com
http://www.houston-imports.com
http://www.the370z.com

http://www.ourvq.com
http://www.n54tech.com

Thousands of real world reviews from real world customers using NST crank pulleys on various makes and models. No cases of engine failure.


Good luck and have fun with all your projects everyone!

[4000GT]

From someone not trying to sell them... I brought one for my 20v, and the engine builder said throw it in the bin, and wouldnt work on my car if I wanted to use it. He builds performance motors and has seen too many failures, so I trust him, practically zero performance gain, and risk of engine failure, pretty easy decision not to use one.

[jondee86]

I have no problem with businesses trying to sell their products, and I
have no problem with people putting products with marginal performance
advantages onto their cars. But I do have a problem with people who
promote their products as being technically sound, when there is a mass
of good engineering evidence to the contrary.

Just to balance things up a bit, here is some information from a harmonic
damper manufacturer, who is also also involved with racing...

http://www.atiracing.com/products/damper..._dinan.htm

While I am sure is is true that NST have many notable successes with
their products; race engines are subject to frequent teardown, and the
replacement of worn or damaged parts. It is also true that sponsored
drivers/car owners are not going to publicize any failure of their sponsors
products. I am well familiar with the car that drops out with an *electrical
failure* caused by a rod that went thru the side of the block and knocked
the starter out of its mountings !!

To say that aluminum pulleys are safe in all cases, is just like saying NOS
is safe in all cases... it is simply not true. And more so for people who are
tempted to install them on their every day driver. I´d just say to anyone
contemplating the use of an aluminum crank pulley, do your homework,
and satisfy yourself that the benefit outweighs the risk. Same thing you
should do with all your mods

Cheers... jondee86

[vlgi]

Today's cars when engineered are often engineered so well that the room for tuning improvements are negligible.

A good example is the S2000, the engine is really an amazing piece of work and it is probably running at its limits, a lot of aftermarket add-ons actually decrease its performance because it is already tuned so well.
Also because it is at the limit by design it means making modifications is potentially dangerous because compared with a car which is not tuned heavily there are engineering tolerances to allow the car to run with less that perfect situations.

When you tune a car you are essentially using the built in tolerances that engineers designed in to ensure it would run well, as you reduce these you increase wear on the engine parts. For every upgrade there is a negative effect as well as positive.

The question is whether the disadvantages outweigh the benefits. For a stock car from the factory the suspension is designed for ride quality more than handling, so you can sacrifice ride quality and get better handling, engines are generally designed more for longevity than performance, you can get more performance out of them but its likely the engine won't last as long.

When engineers in motor sport design a racing car they don't design it to go 100,000 miles maybe a thousand miles, but the requirements for a race car is different from a daily driver or so on. As mentioned above, they have teams that can strip down a car and recondition it often.

Everything is about balance, there are no magic ways to improve a car without having some negative affect as well.

[Miguel - Newera]

Techno Pro Spirit, who have been building 4A-GE race engines for over 20 years don't recommend aluminium pulleys for any engine without a dynamically balanced crank (i.e. with pulley fitted at time of balancing) and they certainly don't recommend it for any race 4A-GE engine reving over 8,000 rpm. We've just had a full build engine from them for a customer in Europe - and the subject came up. Despite having a full Jun billet crank and many other upgrades on this N2 engine - it's running a brand new Toyota original crank pulley with harmonic damper.

You might be lucky reving at over 8,000 with an aliminium pulley, but is it really worth the risk of damaging your crank bearings, after doing an expensive high performance engine build?

I run a standard pulley on my engine, for what it's worth.