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Anyone know somewhere local I can get a dyno plot of shock absorbers? I think--maybe--just possibly-- my long-delayed shocks will be coming soon, and I would like to have the dampers dyno'ed to confirm the vendor's graph prior to installation.

Thanks in advance!

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Steve Carter
1972 Datsun 240Z-- resto pics at http://picasaweb.google.com/srcartermd
2007 GPW Honda S2000-- STR 86

no leads or advice? anything?

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Steve Carter
1972 Datsun 240Z-- resto pics at http://picasaweb.google.com/srcartermd
2007 GPW Honda S2000-- STR 86

Glad you posted this Steve. I'm tinkering with the idea of doing a set for Koni's in the winter for next year.

Here's some pretty interesting stuff (to a shock noob like me anyway) regarding how much variance you can actually have on a new set of OTS Yellows. I didn't realize the adjusters are basically to equalize the damping.

http://farnorthracing.com/autocross_secrets6.html

Thanks for posting the link Ryan.

You'll be hard pressed to find anywhere local that has a shock dyno. You could drive them to Concord/Charlotte after talking to some roundy round guys, but I would just bolt them up and go. Realistically, you probably won't get a lot out of the dyno curves, because like Matt posted, shock dynos are like engine dynos. Every one reads a little differently. - AB

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'14 Toyota Sequoia Platinum 4WD
Super Westerfield Bros - '93 Integra - LeChump Du Jour
STX 93 - Scion FR-S

Matt,

That's a great link, and should be read by every driver (especially novices, based only on how much it helped me during my current novice/newb/hack year(s))--I've pointed 10-12 new drivers to that site since I saw it. He has some bias against adjustable shocks, and with some empiric data to back up his point from what i recall.

Circle Track magazine has lot of great education about shocks...

http://www.circletrack.com/techarticles ... index.html

Is also a good resource. Check out the "related articles" section along the right hand side of the webpage as well.

I also found this to be a useful resource to understanding dyno graphs...

http://nttyres.com/downloads/guide_to_dyno_graphs.pdf

There should not be as many variables as there are with chassis dynos. Changing units of measurement between lbs and newtons, as well as inches/sec and meters or centimeters/sec is all that should be required. After all, the only thing that is happening is measuring the compression force required to compress the shaft at various rates, and then measuring the rebound force required to do the opposite. Temperature, humidity and altitude play little role in that as it is a closed system.

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Steve Carter
1972 Datsun 240Z-- resto pics at http://picasaweb.google.com/srcartermd
2007 GPW Honda S2000-- STR 86

Steve,

Slightly off topic -- some decent reading on spring/dampers as they relate to a vehicle is under the Springs and Dampers section here:

http://www.optimumg.com/OptimumGWebSite/Others/TechTips.html

Chuck

Oh, and no, I have no idea about a local shock dyno except perhaps at someplace like NC State Mechanical Engineering lab or Wolfpack Motosports' lab?

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Current stable:
2019 BMW M2 Competition slicktop 6MT
2011 BMW M3 sedan slicktop 6MT
2007 BMW 328i wagon (slushbox for now)
1975 CanAm 125MX2

The variables are accuracy of the load cell and type of actuation. High end dynos have linear actuators where the lower end have cyclic actuators (motor turning an eccentric "bearing"). Temperature most certainly has an effect, too! Most good dynos have a temp sensor so you can cycle them up to a relatively even temperature and THEN do the test.

I'd bet any of the local race prep shops might do it for a fee. Long Road Racing, Synergy, etc.


--Donnie

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My Blog

rally cross is definitely a shock dyno. though i never heard of a shock dyno..
maybe drive down a pock marked road.


http://www.shockdyno.com/

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