[midlife]

Originally Posted by R&D@Motorwerks

Hello,

The N54 is internally balanced, however, harmonically dampened & harmonically balanced are two different things. You can still have a harmonic damper/isolator on an internally balanced engine (in fact most do).

Based on lots of requests it appears the harmonic dampened version is in more demand. There will only be one type of pulley therefore we have moved on to a harmonic dampened design. The cost is higher than a conventional, but will be worth it in the end. It also should be able to handle any amount of power you can throw at it (which on N54s is important).

Many harmonic dampened crank pulleys are in the $600-800 range depending on the make/model of the car so less than $500 is a bargain by comparison.

Thanks.

as stated by many, how much of a bargin this product may be will ultimately depend on the price and the the performance gain produced

now that you seemed to have gotten some interest, what is the approximate eta for some proformance comparisions and product price ??

[GreenPlease]

So we are looking at 10-12.5hp for this pulley (2.5hp/lb as stated earlier)? Out of curiosity, is that a rule of thumb that applies to all rotational mass in drivetrain?

[BavarianBullet]

Originally Posted by GreenPlease

So we are looking at 10-12.5hp for this pulley (2.5hp/lb as stated earlier)? Out of curiosity, is that a rule of thumb that applies to all rotational mass in drivetrain?

No 2.5HP/lb is not a ROT. More like wildly optimistic. And it only refers to losses from accelerating the [lower] mass; Zero or slow acceleration (i.e. outside of revving in neutral or maybe 1st gear) is going to give you basically zero.

This topic isn't new to cars, just the BMW 335 it seems.

A quick internet search will reveal common experience with non-underdriven (stock diameter) lightweight pulleys and their gains for cars. This link is one of the more useful ones I've come across. Read the comments by MechEE. (you only really need the first and last pages in the thread). Pulley power


It's simple physics such that you don't even need a dyno to measure it- the diff can just be calculated since it's merely a weight difference. (F=MA) I defer to the ME/EE in the URL above. (I'm not interested enough to track down an online physics page that would better illustrate the point).

I'm sorry if I sound like I'm blasting you (I'm not) but this whole thread just gives me a headache and I'm surprised others haven't said anything yet but I suspect that will come with the dyno-tested HP claims this week.

[roozie2001]

i'd like to know what kind of dampners you guys are using?

[cu_north]

Originally Posted by midlife

as stated by many, how much of a bargin this product may be will ultimately depend on the price and the the performance gain produced

now that you seemed to have gotten some interest, what is the approximate eta for some proformance comparisions and product price ??

+1

[pdjafari]

I ran a Unorthodox lightened crank pulley on my G35 coupe years ago and it didn't produce 1hp on a dyno... Actually the car didn't feel any faster, although everybody who had one claimed it 'revved' quicker/easier (more freely)



Im not so sure its worth the risks of playing with this engines harmonics (considering an engine can cost 15k), those variables are designed/researched by BMW engineers not simply taking into account physics and lightened crank pulley car knowledge

[R&D@Motorwerks]

Hello,

Performance testing will be completed sometime in the next few weeks as we have opted to test the final harmonic dampened version in order for the results to be as accurate as possible to the final production unit. Therefore, we have chosen Dyno Dynamics as the dyno of choice in order to obtain the most accurate results possible before & after. We do thank everyone for their patience in this regard.

Furthermore, its very difficult to compare between vehicles as all crank pulleys are different. How much power can be extracted depends on numerous factors such as, amount of weight reduced, overall radius of mass, and other factors as well. Also roughly 85% of the gains from crank pulleys come from mass reduction, only 15% comes from underdriving (directly from URIs literature themselves). Mass reduction is far more significant & important than underdriving itself (without any of the negatives). This is especially true on German vehicles which typically have the heaviest ones by far, where as most asian import car pulley systems are already very light and there isn't much power to be extracted out of them. Some are so light that underdriving is the only option. Comparing apples vs. oranges won't work in this regard.

Regarding the E46 & E90 pulley comments, the entire stock crank pulley assembly is actually very heavy, the only difference is the actual serpentine pulley belt is a separate piece from the harmonic damper so it appears to be light (the stock piece is already lightweight aluminum). The stock E90 & E46 m3 harmonic dampers are very large and almost the size of a flywheel, so they are certainly not light. All the aftermarket versions of the E90 M3 pulley are purely for underdriving purposes, there is virtually no difference in mass, so its difficult to compare the two. This is also why they only makes gains at the top of the power band. The BMW 335 pulley is a one piece unit which incorporates everything into one pulley

Accessory pulley systems work as a function of rpm. The higher the RPM, the larger the differential between the rotation of the stock accessory pulleys vs. their underdriven counterparts, as a result the more rpms you can spin, the more of a difference it makes (which is why on an E90 M3 with 8000rpm+ redline it makes sense at least in that application). However, on a 335 with a redline lower by 1000rpm, the effects are not as profound.

Furthermore, lightweight crank pulleys work as a function of torque; their maximum gains are always at peak cylinder pressures (aka peak torque) which is in the middle of the power band. The gains are held throughout the powerband from just after idle all the way to redline, so there is more "meat under the curve" as many may say, from lightweight crank pulleys vs. underdriven crank pulleys. Straight line performance is all about torque and the ability strengthen & broaden the torque band will significantly improve straight line performance more so than just peaky high end HP.

In addition, turbocharged cars respond exceptionally well to lightweight crank pulleys due to their nature and often the highest gains are on turbo charged cars. The perception of lag is also significantly reduced as the engine is able to accelerate much more quickly at lower rpms (not that lag is a terrible issue on twin turbos, but some complain about lack of responsiveness). Lightweight crank pulleys help alleviate that and significantly improve engine responsiveness as well.

We do thank you for all your questions and for your patience during the development process. We will provide more info as soon as it is available.

Thanks

[1clean335i]

Originally Posted by R&D@Motorwerks

Many harmonic dampened crank pulleys are in the $600-800 range depending on the make/model of the car so less than $500 is a bargain by comparison.

Thanks.

Really?
http://www.horsepowerfreaks.com/sale...onic_Balancers

[R&D@Motorwerks]

Originally Posted by 1clean335i

Really?

Hello,

Yes, in fact that was being conservative. Evosport's are $995. So, you can see that the mid 400s is actually a fair price and is in line with most dampened pulleys out there. It is understandable that everyone wants something for nothing, and there's no such thing as too low a price, but its important to be realistic and fair.

Thanks.

[Ryan@Motorwerks]

Guys, please worry about pricing when it's actually released. We are still working on R&D so even we are unsure of what pricing will be. I promise you guys though we will try our best on pricing and the pricing will fairly reflect the quality and time put into the finished product. Talking about pricing now will get us nowhere and create a lot of unneeded animosity.

[MuchMoore]

Originally Posted by Ryan@Motorwerks

Guys, please worry about pricing when it's actually released. We are still working on R&D so even we are unsure of what pricing will be. I promise you guys though we will try our best on pricing and the pricing will fairly reflect the quality and time put into the finished product. Talking about pricing now will get us nowhere and create a lot of unneeded animosity.

Good point, Im interested.

[dlbrooks18]

^ me too if there are good power gains

[SCCAForums.com]

IMO... if it ins't underdrive... and lightweight... don't expect any real HP gains...

The problem with just reducing weight... and keeping the same diameter... is the 'rotating' mass is so concentrated... (call it a 7" diameter???) vs. lightweight Flywheel... more like 14" diameter... your weight is much further away from the center... so weight reduction multiplies gains... but with such a small diameter to start with... your not going to get much benefit of the weight multiplication unfortunately.

Kudos for the effort though,
Dave

[grkm3]

Not to bust ballz on this thread but I would never run a crank pulley on a inline 6,Its been done on the e36 and everyone that ran the crank pulley ended up messing up there engines.That is why no one ever runs the crank pulley anymore(only a few brave do)We opt for every other pulley except the crank pulley.

Bmw knows what there doing and that weight of that pulley is there for a very good reason,also knowing the engine is ballanced for the stock weight crank pulley makes it a huge gamble on having the engine last down the road.

Im running a ltw flywheel,and under driven uuc pullies on everything but the crank,I saw maybe 3 whp from doing it but the car rev matches like bannanas lol.

I would underdrive everything else before I would ever think about touching the crank pulley.

again not to bash on the thread,but I have a huge feeling people will be spinning there crank bearings 30k miles down the road with these just like us e36 guys were.Ohh and also spinning the oil pump nut right off.

[R&D@Motorwerks]

Originally Posted by grkm3

Not to bust ballz on this thread but I would never run a crank pulley on a inline 6,Its been done on the e36 and everyone that ran the crank pulley ended up messing up there engines.That is why no one ever runs the crank pulley anymore(only a few brave do)We opt for every other pulley except the crank pulley.

Bmw knows what there doing and that weight of that pulley is there for a very good reason,also knowing the engine is ballanced for the stock weight crank pulley makes it a huge gamble on having the engine last down the road.

Im running a ltw flywheel,and under driven uuc pullies on everything but the crank,I saw maybe 3 whp from doing it but the car rev matches like bannanas lol.

I would underdrive everything else before I would ever think about touching the crank pulley.

again not to bash on the thread,but I have a huge feeling people will be spinning there crank bearings 30k miles down the road with these just like us e36 guys were.Ohh and also spinning the oil pump nut right off.

Again comparing apples & oranges. Its a completely different pulley design than the E36 models. Further more, thousands of people still run them on the E36s and many of them have put over 50k on their cars with no problems. With that said, these will be harmonic dampened so none of those concerns are issues in this case and only apply to your specific E36 application. Underdrive accessory pulleys simply don't provide much meat under the curve and are rarely worth it in the end as they only address power in a very small concentrated portion of the power band, they do virtually nothing on the low end to mid range. Furthermore, flywheels can be just as dangerous if not more dangerous if not properly designed. In addition, Inline 6s are actually the best motors to run pulleys on as they are the most naturally well balanced engines (along with V12s) due to their inherent design.


Again, everyone's patience is much appreciated, simply wait for the dynos and all questions will be answered.

Thanks.

[dlbrooks18]

Originally Posted by R&D@Motorwerks

Again comparing apples & oranges. Its a completely different pulley design than the E36 models. Further more, thousands of people still run them on the E36s and many of them have put over 50k on their cars with no problems. With that said, these will be harmonic dampened so none of those concerns are issues in this case and only apply to your specific E36 application. Underdrive accessory pulleys simply don't provide much meat under the curve and are rarely worth it in the end as they only address power in a very small concentrated portion of the power band, they do virtually nothing on the low end to mid range. Furthermore, flywheels can be just as dangerous if not more dangerous if not properly designed. In addition, Inline 6s are actually the best motors to run pulleys on as they are the most naturally well balanced engines (along with V12s) due to their inherent design.


Again, everyone's patience is much appreciated, simply wait for the dynos and all questions will be answered.

Thanks.

thanks for the info, excited about this potential mod

[Kevin@AKMotorwerk]

Originally Posted by grkm3

Not to bust ballz on this thread but I would never run a crank pulley on a inline 6,Its been done on the e36 and everyone that ran the crank pulley ended up messing up there engines.That is why no one ever runs the crank pulley anymore(only a few brave do)We opt for every other pulley except the crank pulley.

Bmw knows what there doing and that weight of that pulley is there for a very good reason,also knowing the engine is ballanced for the stock weight crank pulley makes it a huge gamble on having the engine last down the road.

Im running a ltw flywheel,and under driven uuc pullies on everything but the crank,I saw maybe 3 whp from doing it but the car rev matches like bannanas lol.

I would underdrive everything else before I would ever think about touching the crank pulley.

again not to bash on the thread,but I have a huge feeling people will be spinning there crank bearings 30k miles down the road with these just like us e36 guys were.Ohh and also spinning the oil pump nut right off.

not to argue but do you have any direct proof of engine damage directly related to the light weight crank pullley? i have ran pulleys on a few mustangs, and so does everyone i know, and never spun a bearing due to it, maybe coincidence that the people you know of beat the crap out of their car beyond its limits to try to test the new pulley? or maybe had an oil pressure problem in the past and didnt push it to the limits till after the pulley was installed?

[cu_north]

I had a non harmonically dampened, non underdriven pulley on a 350Z, put 40,000 miles on it. The car ran as great as it did the first day I put it on. Added about a dozen horsepower. I'm less worried about long term effects and more about potential gains for this engine.

[hsleiman]

FWIW I have a lot of STI and WRX buddies running lightweight pulleys for over 10K miles and having no problems with them. It's the underdriven ones you have to worry about.

EDIT: Before reading this thread I thought a lightweight crank pulley was a no-brainer but I'm seriously having second thoughts now.

[roozie2001]

Originally Posted by hsleiman

FWIW I have a lot of STI and WRX buddies running lightweight pulleys for over 10K miles and having no problems with them. It's the underdriven ones you have to worry about.

EDIT: Before reading this thread I thought a lightweight crank pulley was a no-brainer but I'm seriously having second thoughts now.

what r u talkin about dude. Ive ran numerous cars with underdriven crank pulleys. Nothing happened to any of them.

[hsleiman]

Originally Posted by roozie2001

what r u talkin about dude. Ive ran numerous cars with underdriven crank pulleys. Nothing happened to any of them.

I mean I could be wrong, don't take my words as fact, just stating what I have been told through the years... But from what I understand, underdriven pulleys take away power from the other accessories of your car, such as the oil pump, and can cause overheating.

Feel free to correct me if I'm wrong though!

[Kevin@AKMotorwerk]

Originally Posted by hsleiman

I mean I could be wrong, don't take my words as fact, just stating what I have been told through the years... But from what I understand, underdriven pulleys take away power from the other accessories of your car, such as the oil pump, and can cause overheating.

Feel free to correct me if I'm wrong though!

unless the oil pump was belt driven then the underdrive pulley wouldnt affect it, usually the oil pump is either driven off the crank or cam gear, and no matter what pulley you have on it wont affect the oil pump. i have seen charging problems with a full underdrive pulley sets because they slow down the alternator.