Harmonic Damper worth investing in?

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Harmonic Damper worth investing in?

Postby yabaiani » Sun May 15, 2022 12:13 pm

For higher than average HP builds or higher RPMs (9k+), is a harmonic damper worth getting? Does anyone know of reputable brands that sell one? Google search only found a couple, but have no clue which one to get:

Ross Performance Parts

https://rossperformanceparts.com/produc ... ic-damper/

BHJ dynamics

https://harmonicdampers.com/index.php?m ... ki91bae192

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Re: Harmonic Damper worth investing in?

Postby Davegt27 » Mon May 16, 2022 12:19 pm

I know the WSR race cars use them

they used to have a forum (maybe ask them)
https://www.tapatalk.com/groups/sportst ... b2f6a5d3c4

I still have my unorthodox racing 4AG pulley that I plan to use some day lol
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Re: Harmonic Damper worth investing in?

Postby sirdeuce » Mon May 16, 2022 7:55 pm

Most of the people I know don't really care about it.


Any machine that has parts that rotate typically have certain operating parameters that will set up harmonics. Doesn't matter how well your machine's balanced internally there will be harmonics.

Energy pulses can cause upsets in the machine's operation. Such pulses can and do cause power robbing inertial variations that can cause some damaging weight transfers.

The "balancer" is typically touted as a device to smooth out those inertial variations, which really is how it works. The balancer also smooths out the harmonics as well, but mostly smooths the power and inertial variations.

Unless you are spending most of your time at high RsPM constantly the balancer really isn't necessary. If you spend time on the track I'd say use the balancer. If you spend most of you time in cross town traffic, eh, your choice. If you're the "gotta have it perfect" type don't leave anything out of your build. I put 60k miles on one of my AE82s while running an undersize pulley on the crank without issues. I drove the dog piss out of that car until it got T-boned. Then that engine went into a friends car and he drove it for years.

In a nutshell, your engine, your discretion. Most of the people I see out there run "light weight" solid pulleys for the "added" performance or just because they're pretty.
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Re: Harmonic Damper worth investing in?

Postby jondee86 » Mon May 16, 2022 10:35 pm

Some good information in this video... https://www.youtube.com/watch?v=J1BGsgIZ_Ek

Just make sure you get one that will line up with the other pulleys you are using as FWD and
RWD 4AGE pulleys have different offsets. Ross Racing do an AE86 two-row one that matches
the OEM RWD pulley offset.

Cheers... jondee86

PS: If anyone is interested in a pretty good "no BS" explanation of the theory behind harmonic
dampers, take the time to read this...
http://harmonicdampers.com/index.php?ma ... &chapter=0
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Re: Harmonic Damper worth investing in?

Postby fiveten » Wed Jun 22, 2022 11:16 am

I think it's worth investing in it because, if our 4AG is making anything over 150 HP, we have put a lot of money into it; might as well spend a little bit more for safe measure. Another option is to shave off the stock pulley and make it a single row and balance it with the rotating assembly.
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Re: Harmonic Damper worth investing in?

Postby beyjer » Wed Jun 22, 2022 9:46 pm

I’m running the Ross pulley, so far so good.

I agree with what was said above, if you’re doing track days then it’s probably worth it, if street car, oem is likely sufficient.