Fluidampr - The Independent Test 

by Bart Hockerman

I was honestly very intrigued when I read the article here on MotoIQ about the Development Of The Fluidampr Crankshaft Damper. Seeing the dyno charts showing improvement in power and torque on a Stock FRS and having a pulley/damper that should reduce harmonic stress on the engine would be the hot ticket. It really almost looks too good to be true. 

Here is the thing, Subaru claims that the boxer motor is supposed to be balanced due to its boxer engine design. “The pistons face away from each other in a 180º symmetrical layout around the crankshaft and work to balance out each other’s vibrations, delivering a smooth, shudder-free feel. “ Knowing this, can the Fluidampr improve on what Subaru uses from the factory to further smooth out the engine harmonics while making more power? Could this damper honestly live up to what its dyno numbers claimed? Me being the skeptic I am, I wanted to give it a go on a proper modded BRZ to see what it would do and how it would perform. 

First things first though, I needed to get my hands on the BRZ/FR-S Fluidampr! 

With that thought I reached out to one of the MotoIQ militia and inquired about the acquisition of the BRZ/FR-S Fluidampr. Next thing I knew there was a package at my front door waiting for me. I will say it was one of the best if not the best packaged products I have ever had the pleasure to open. It really would be able to survive the worst handling UPS, FedEx or USPS would be able to throw at it. Big props to the Fluidampr packaging dept.


Here is the extremely well packaged Fluidampr.

Open it up and see what is inside! What you can’t really see though is the expanded foam that is behind the instruction envelope that fully encased the heavy plastic bag that the damper was in. It is the best "void fill" when shipping items like this.

The weight game:

Weight, it is part of the age old debate that has been argued amongst gear-heads forever. Does lighter equal faster and what do you sacrifice by going lighter? Every give has a take. When replacing the crank damper/pulley with a lightweight undamped unit you are removing rotational mass. Your engine in theory should rev faster and lose revs faster, however you do sacrifice the damping aspect of the of the stock unit which lessens the harmonic vibrations in and on the engine. Another side effect of the vibrations may be increased wear on internals. There is a reason that the OEM manufacturers don’t use solid crank pulleys and I would put money on it that a solid pulley would be way cheaper to make than a damped one.

Our contenders for this bout will be the Perrin Performance Crank pulley, our OEM Subaru damped pulley and the pulley of the hour, the Fluidampr.

Perrin claims are simple and straightforward: “The PERRIN Performance Crank Pulley weighs just 1.2 lbs, which is 3.7 pounds lighter than the stock OEM crank pulley. This reduction in weight from the crankshaft is equal to removing more than 100 lbs of vehicle weight! Throttle response, horsepower and torque are all increased with this easy to install part.”

The OEM Subaru crank pulley is a standard OEM multi piece rubber dampened unit. It is what the engineers design for the FA20 engine.

The Fluidampr pulley does make some claims about their crank damper:

“Protect your engine. A Fluidampr performance damper provides premium, broad range control of destructive crankshaft torsional vibration for optimum performance and durability. Install as an upgrade to OEM elastomer style harmonic balancer, when horsepower is gained, or when rotating assembly parts change to reduce wear on critical internal engine components. Features high quality, long lasting viscous silicone damper technology with precision CNC machined and computer balanced high-grade steel components. No tuning or maintenance required. SFI 18.1 approved, race proven for over 25 years. Made in the USA.”

That stated let's have the weigh in.


Perrin's crank pulley was our only non-damped unit and is also the Flyweight at a whopping 1.20 lbs.
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Thursday, September 03, 2015 5:19 AM
A shame Fluidampr doesn't make these for Isuzu 3.5 V6s. Project VehiCross could use a lesson in refinement. Interesting results, especially with the loss of power on the lightweight crank pulley.
Thursday, September 03, 2015 6:12 AM
What's really interesting is that the stock one makes the most power, per your numbers.

Did you only take one dyno run with each pulley?
Pablo Mazlumian
Pablo Mazlumianlink
Thursday, September 03, 2015 8:04 AM
It's also sometimes a good idea to test real-world acceleration numbers (like a third gear, 30-90mph dyno-like pull...not necessarily from 0mph, which leaves room for more error) so that you eliminate the possibility of the greater WHP coming from the heavier pulleys solely due to increased engine load. I've seen these in most occasions when testing same-size, but heavier road wheels--the heavier translating to more WHP, especially up top, on an inertial Dynojet (and especially true with turbo-charged cars). What I've also seen is, like when testing LTW flywheels, 3rd gear-on yields little results (sometimes I'd see 3-4hp in 3rd but at least by 4th it was even) whereas 1st and 2nd gear had huge differences. I wonder what the differences in these pulleys would have shown on the dyno in like at least a 2nd gear pull.
In any case, I've got a Fluidampr in one of my cars and have had zero probs long term! :)
Thursday, September 03, 2015 8:21 AM
What gear were the dyno pulls done in and what was the rate of acceleration (engine rpm/s sweep)? Was it the same for all pulls?

As Pablo mentioned, the power difference will only become apparent if the engine speed rate of change is relatively high. Doing a pull in 2nd gear at an acceleration rate comparable to real world accel would give the most meaningful results for autocross competition purposes. Assuming that is what you are after here.

Thursday, September 03, 2015 9:03 AM
@ MDR- We made roughly 7 runs per pulley and each run varies slightly. We looked at the consistency of the runs and chose a run from each pulley that was the best in it's group even though it may have been only .3 hp better.

@ Pablo - it was considered to try different gears, however it would not have been consistent with how most dyno runs are done.

@ JMcD - Dyno runs were on in 5th gear. The rate of acceleration was kept as close as it could without having a machine control 100% of the test. Our Dyno guru Tim Martin of King Motorsports is very experienced/trusted at his job, that is why we chose him for this test.
Mike Kojima
Mike Kojimalink
Thursday, September 03, 2015 9:57 AM
On our Project STI the Fluidamper made a huge difference in smoothness but we did not see a gain in power. The smoothness difference was profound.
Thursday, September 03, 2015 11:03 AM
@ 2superblus - What rpm/s rate were the tests run at? The relatively small (few hp max) you are chasing here will be hard to reliably measure even at very fast engine speed rates of change.
Thursday, September 03, 2015 11:57 AM
@JMcD- I mis-typed our runs where taken in 4th gear. Each run was roughly 16.5 seconds long. We understand that not everything can be perfect, we did our best to keep the test as consistent as possible. I guess I am not quite understanding what you are try to get at.
Thursday, September 03, 2015 1:47 PM
he is trying to say that the rate of rpm change (how quickly the engine pulls though the gear) will affect the performances of the pulleys. A low gear fast revving pull will show performance differences gained/lost by rotational inertia far more than a slow rpm gain high gear pull. The high gear pull should show engine performance clearly, but not necessarily acceleration rate potential of the different pulleys.
Thursday, September 03, 2015 2:13 PM
As a former design engineer for crankshaft dampers I just wanted to point out a couple important items.

The crankshaft damper has nothing to do with engine balance and vibrations. Motion and oscillation of the powertrain, as an assembly, is addressed by your engine mounts, transmission mounts, and potentially roll restrictors.

The purpose of a crankshaft damper is to reduce the angular twist / deflection of the crankshaft. Combustion creates pressure. Pressure becomes load into the connecting rod which creates torque on the crankshaft. That torque creates deflection of the shaft as it's not infinitely stiff. Depending on the material, journal offset, length of the shaft, and loads created in the cylinders you can see several degrees of angular deflection in the crankshaft. I've seen an OEM crankshaft which displayed 7° of deflection without a damper. With the damper it was under 2°.

The mass of the crank damper and the stiffness of the spring element (the rubber part) are vital to the effectiveness of the damper. They control the resonant frequency of the damper and impact the effective damping. If you change the mass or change the spring stiffness you change the frequency at which it operates. If you don't have enough mass, even at the correct frequency, you don't provide sufficient damping. An incorrectly tuned damper could actually make things worse.

$0.02 submitted. Carry on :D
Thursday, September 03, 2015 9:36 PM
The real performance gains to be had from a fluidampr, or other high-performance crank damper such as those made by ATI and Innovators West, is in that they allow you to lighten up OTHER parts of the drivetrain while still retaining great streetability.

This is most relevant on weightier performance cars that come equipped with a Dual Mass Flywheel. Removing the DMF often yields great improvements in engine dynamics and feel, but at the cost of smoothness; especially at idle. This unwanted side-effect can be largely, or sometimes entirely, mitigated through the use of a really good crank damper. Older BMW M3s, Nissan 350Z/370Z, Hyundai Gencoupe, and many other performance cars besides all *hugely* benefit from this type of modification.

Swap out the heavy DMF for a light, strong Single Mass Flyweel and then drop in a hi-po crank damper. These straightforward changes will TOTALLY alter the character of many cars for the better. The combination of quickened engine response and enhanced smoothness is utterly intoxicating. All of the stereotypes about being "at one" with the drivetrain come true and you simply delight in driving the car.

THAT is what these high-dollar crank dampers are good for. Fluidampr and the other manufacturers may make all kinds of claims about power gains, but it's really irrelevant. The smoothness they introduce is real and it allows we as tuners to 'get away with' more drastic mods that can often be obnoxiously racy on the street.
Friday, September 04, 2015 6:15 AM
@2superblus - As others have stated, the performance gain of a lower rotating inertia is proportional to the rate you are accelerating it at. Torque = Inertia * rotational acceleration. Power = Torque * Rotational Speed. On the dyno, if you aren't increasing the rotational speed of the interia very fast, you aren't going to see any difference in torque or power, as measured by the dyno.

At 16.5s per 6000rpm sweep, you're accelerating the damper's inertia at ~360rpm/s. In second gear, at autocross speeds, you'll be around 1100rpm/s. That means at WOT in 2nd gear, you're using three times as much torque to accelerate the damper's inertia that you are in the dyno test shown here (regardless of how consistent the dyno testing is).

With some overly optimistic assumptions, the most torque difference you are going to see from an inertia difference standpoint at 360rpm/s is around 0.6 ftlbs (based on your weight measurements).
Saturday, December 26, 2015 8:28 PM
Amazing how the UR pulley made so much power everywhere but the Perrin didn't. Something seems very strange that the lightest part didn't make the most power or even beat the OEM. I know our pulley is almost a half lb. lighter in straight mass but our rotational mass is 30% or better. The Perrin should have performed to atleast a minimum of half the gains of the UR test last year. Just very weird!
Sunday, December 27, 2015 6:32 AM
@unorhtdox I totally agree it was strange and went against the theories that I myself had held for so long. I would be curious to see the actual test data that UR has for your pulley or even for that matter see it tested vs the others that were used here.
Sunday, December 27, 2015 8:18 AM
Due to the ever present concern of manufacturers manipulating dyno data to their advantage we choose to have the media or consumers do testing independent of any influence.

Through our own testing eons ago we developed a formula that allows us to determine the gains to be expected based on weight reduction and moment of inertia.

Since our pulley is 3.8 lbs lighter than the stock pulley we knew gains would be in the 6-8 HP range which the MotoIQ test proved was spot on. We also are confident gains would rise slightly with tuning as this engine is notoriously stingy allowing gains. Our formula shows a maximum of 10.26 HP, at the wheels, based on the normally aspirated setup.
Sunday, December 27, 2015 9:56 AM
So what does the UR pulley weigh for the FA20 engine?
Sunday, December 27, 2015 10:15 AM
1 lb static weight of the current 1st Gen version.

The moment of inertia of our pulley is 30% less then the closest comparable pulley due to our design focus being on maximum weight reduction towards the outer diameter. This in effect makes our pulley feel, to the crankshaft, like it weighs under 3/4 lb.

If the FRS/BRZ community wants we can get the pulleys static weight down to 3/4 lb. and rotational weight down to 1/2 lb possibly less.
Sunday, December 27, 2015 10:26 AM
Every ounce counts, why leave any power on the table especially when price is not massively different. It's not like we are $500 and the other stuff is
$100. Not to mention we include a new premium belt. Plus we would be glad to make the accessory pulleys, tensioner and idler pulleys to maximize the weight reduction even further. It's up to the community, we can do anything and make the litest.
Sunday, December 27, 2015 11:23 AM
Interesting, most manufaturers kits for the complete pulley replacements are quite expensive.

It would be interesting to test a crank pulley swap vs a full swap of all of the best pulleys.

We did also notice that the engine harmonics were quite loud with the undamped pulley too. Not quite sure how that will affect the engine in the long run.
Sunday, December 27, 2015 12:08 PM
The reason the sets are over priced is because we don't make one, if we did the copy cats would cut their throats to under cut us. The saddest part is they don't even make a truly lite weight set worthy of the price they are gouging the community with.

Harmonics of the undampened pulley are a function of the design, if you read the MotoIQ article about our pulley they were clear there was no difference in audible harmonics with our pulley.

The fancy graphs in the damper propaganda article mean absolutely nothing as they don't say whose part they tested and they don't show any relationship to any end result. No broken part or engine, no point of expected in rpm or mileage.

Fact is we have been on EJ for 18 years from stock 1.6 NA motors to 600+ 2.5 turbos and now Toyota 2.0. Never one failure just fear mongering to pawn an over priced, unnecessary and over weight anchor of a pulley.
Sunday, December 27, 2015 4:06 PM
The greatest shame is the performance enthusiast community is the one that loses. There is not enough market to justify the imitators and the innovator. This results in stifled development, inferior compromising parts that are hawked for ever lower prices that would make you think the product is a commodity. The reality is far from this delusional race to the pit of insolvency. Pulleys have one function (under drive or stock diameter), it's not like an exhaust or a header that has a specific sound or focus in improving the power band. Or wheels which are a visual choice especially since they are seen at all times. This can be expanded on to adnausium.

We have no interest in a monopoly if there was or were actual apples to apples competitors.

We've been here for over 18.5 years and we are not going anywhere. We are focused on one category, pulleys, providing second to none product and customer service. We leave no stone unturned in always being the best, the litest, the nicest finish and as the best value. Providing only the best supporting components from belts to bearings and everything in between. Meaning we make the most power across the powerband every time for every application. Plus we back it up with a 5 year transferable warranty.

All products have a minimum retail cost with respect to providing a complete solution with no compromises. If you can't afford it don't cut a corner and leave anything on the table. Aspire and save then you'll be sure you haven't been short changed for what amounts in the grand scheme of life as peanuts. Not to mention what the quality question could mean in potentially thousands of dollars of repairs and aggravation as a result of cutting the corner. In most cases well less than $100 guarantees you the total package and long term piece of mind plus resale backing of any remaining warranty to the next buyer.
Monday, December 28, 2015 9:56 AM
A simple but unfortunate comparison/correlation that supports our point is that too many out there want to spend the same or less than a pair of sneakers (roughly $100-125) as a they would for a critical precision component going on their engine worth up to $10K or more depending on its build not to mention the labor costs and downtime.

Thursday, March 31, 2016 4:49 PM
Does adding a fluid damper simulate the effect of balancing a crankshaft when blueprinting an engine? Are there any negative effects to adding a damper? I've noticed a certain roughness in my FR-S during idle. I've been told it's just a characteristic of the flat-4 engines.
Thursday, March 31, 2016 7:59 PM
It does not, balance is not simulatable. An engine is either balanced or it is not. As long as the damper isn't heavier in static or rotational weight and it is balanced within the specs sets on the original engine there would be no negative effects.
Anonymous User
Anonymous Userlink
Monday, September 18, 2017 10:30 PM
Thursday, September 21, 2017 8:56 AM

There are a lot of misconceptions in this thread about weights “breaking free” at higher RPM ranges, which is not the case at all. The internal inertia ring oscillates back and forth, shearing through the silicone which turns that energy into heat and dissipates it out the damper housing. The silicone is 45,000 times thicker than SAE 30 weight motor oil, there is no way to “break free” with that kind of viscosity. When we clean our silicone off of parts we have to scrape it with a putty knife, then scrub it with scotch brite and solvent to get it to come off. There is no way for the parts to break free at the surface finishes we use.

Viscous dampers can be found in some of the highest revving racing engines on the market today such as the Lexus LFA which uses a 10” viscous damper and is commonly known as one of the fastest revving/smoothest engines ever made. The engine revs from idle to redline in just .6 seconds, so fast that the engineers had to fit a digital rev counter due to the conventional needle couldn’t keep up. Also add the Audi R8, Bugatti Veyron, Lamborghini Gallardo, McLaren’s, high end BMW’s and one of the Big 3’s endurance racing team cars, not to mention the vast majority of all diesel/natural gas engines (some of those engines cost more than most families homes). Viscous vibration dampers like Fluidampr provide excellent vibration control because they operate on a bell curve of vibration control, rather than a start stop narrow frequency band like most tuned rubber parts. This frees up power robbed by the vibrations in the engine. Vibratech TVD (Fluidampr’s parent company) is a global supplier to our military, OEM’s and aftermarket based out of NY in a 130,000 Sq. Ft. facility with over 70 CNC machines plus robotic damper manufacturing cells to keep up with OEM demand.

Furthermore, if OEM’s were able to use just a pulley to control detrimental vibrations they would. It is much more cost effective to mass produce a one piece pulley than a bonded rubber or viscous type damper. We have been working with global OEM’s for over 60 years and they care most about 3 things; 1. Safety, 2. Cost savings, 3. Weight reduction.

The purpose behind a damper is that a pulley cannot do anything to protect against torsional vibrations. As previously stated a damper’s job is to counteract crankshaft twist by taking that energy and converting it to heat. There must be a force to counteract combustion pressure put on the crankshaft with each ignition fire as this is what causes the crankshaft to twist ahead of its natural rotation and rebound back subsequently transferring vibrations back through the crankshaft and vital engine components. A damper is not there to make power, this is just an additional benefit as you decrease or minimalize these vibrations.

We trust MotoIQ’s audience will make informed decisions. Some of whom are professional engineers themselves. Fluidampr and Vibratech TVD offers our resources to help them solve torsional vibration challenges, which includes being commissioned by OEM’s and professional engine builders to perform TVA (torsional vibration analysis) in order to design an application specific product and provide the best vibration control available.

Our goal is not to highjack this comment section with who is “better”, we are happy to discuss any of this in greater depth – please contact us @ sales@fluidampr.com

Sorry about the long read =)
Thursday, September 21, 2017 9:09 AM
Paul@fluidampr ~ Thanks for the information. As was stated in the article the engine ran much smoother with the Fluidampr installed and it was much more enjoyable to drive on the street.
Thursday, September 21, 2017 2:45 PM
You are most welcome :)

Wasn't questioning or interested with most of the article. Opinions are a dime a dozen and the same goes for preferences. I just happen to prefer my performnace vehicles to operate in a sporting manner not as over stuffed living room furniture.
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