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Old 06-21-2007, 02:02 PM   #1
ButtDyno
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Default How to come up with some sort of objective measure for "ride quality"?

So... trying to make ride quality comparisons over the interwebs is quite difficult.

Some people have different tolerance for stiffness than others. Someone coming from a Cadillac might find a Koni shock harsh, and someone coming from JIC's might find a Koni shock plush, even when they're the same shock.

Plus, people have a tendency to defend whatever they just spent $2K on as the best thing ever

We can look at a shock dyno to get some hints, but in the real world there are a ton of variables:
-Tire choice (stiff sidewalls vs floppy all seasons)
-Air pressures
-Wheel choice (more diameter = less sidewall = more harsh)
-Spring rates
-Shock settings (when applicable)
-Roads you're driving on

The discussion of the Ohlins Sportlines in the one thread got me thinking. What kind of tests can we all do, independently, that could begin to establish some benchmark for ride quality that we can demonstrate to other people?

I was thinking along the lines of, take a video from inside the car of your knees while driving over a fixed speed on a bumpy road, and then the same thing on a "typical" stretch of highway. Maybe look for some freshly paved stuff.

And if you have a Chasecam or some external camera mount, maybe mount it on the fender and do the same thing, pointing the camera at the wheel, so we can compare the camera's angle to what's happening with the front suspension.

The other question is, with such a test, what variables (other than the ones listed above) would people need to account for in order to fully document their situation?

I dunno, just rambling. I am just tired of the "best ever" type hyperbole and I'm trying to figure out how to get people's product reviews to include more context.

john
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Old 06-21-2007, 02:29 PM   #2
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Quote:
Originally Posted by ButtDyno View Post
The other question is, with such a test, what variables (other than the ones listed above) would people need to account for in order to fully document their situation?
No road is the same, so thats a very big variable.

The video cameras also will have different image stabilization systems in them, so the shakey video will also vary from person to person. Its a good idea, but I wouldn't call it "objective" at all.
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Old 06-21-2007, 02:35 PM   #3
ButtDyno
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I didn't claim objective... just "some sort of objective"

With a Chasecam you don't have any stablization, since the camcorder is just acting as a VCR. But that's a good point too. Crap!

john
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Old 06-21-2007, 02:41 PM   #4
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The whole idea itself is contradictory to your screen name

But I definatley like the idea.
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Old 06-21-2007, 02:42 PM   #5
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A full cup of water of some standard size sitting the cup holder. After the test drive measure how much water has left the cup?

I know there are lots of details missing, just a quick idea.
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Old 06-21-2007, 03:54 PM   #6
deathfrombelow
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Quote:
Originally Posted by ButtDyno View Post
I didn't claim objective... just "some sort of objective"

With a Chasecam you don't have any stablization, since the camcorder is just acting as a VCR. But that's a good point too. Crap!

john
I think this is a huge step in the right direction, but not only do you have to worry about the cameras stabilization adjustments, but also the ammount of play in different peoples camera mount.

Maybe you could take a video of a car driving over a speed bump at a set speed. The camera would be perpendicular to the car so that it could film the wheels at a right angle. Then have someone standing on the other side of the car with a yard stick at a set distance so that you could get an easily measurable relative measurement of how much that car's height increases (of say, the hood) as it goes over the speed bump. This sounds kind of silly, but most of us have speed bumps in our neighborhoods so it shouldn't be too hard to find a good spot to do this.
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Old 06-21-2007, 06:05 PM   #7
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....maybe you can find someone who has the equipment, a nose for experimentation and is willing to document the tests you speak of using local members cars as the subjects (under the same conditions, using the same roads, etc.). Just thinking out loud but that may help eliminate some of the issues with variations you speak of when dealing with individuals running their own tests. ……obviously, a region with a wealth of local members (with various suspension modifications) willing to participate would be ideal.
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Old 06-21-2007, 06:12 PM   #8
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Maybe some kind of accelerometer based measuring device to show what sort of peak upward velocities the car is doing. Then just transfer the equipment to various cars like a benz, a caddy, a bmw, various suby suspensions. Then you can at least see, that compared to this such and such model bmw, the jic equipped scoob drove so and so.
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Old 06-21-2007, 06:23 PM   #9
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Definitely an objective, tell-all test would be an accelerometer. If you can place an accelerometer on the passenger seat, and drive over the same road types in different cars, that would be very, very telling. You could quantify responses to all different kinds of excitations and frequencies, modes, resonances, impulse, shock, etc etc etc.

You could also probably separate out the contributions of the tire, suspension, seat cushion ,etc. as well since they mostly respond in different frequency ranges.
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Old 06-21-2007, 07:32 PM   #10
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also would be nice to put in the back seat, as ride quality from the back seat is very different from the front.


so who has an accelerometer at home?
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Old 06-21-2007, 11:10 PM   #11
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http://www.sensr.com/gp2.html

How about someone with a suspension business who could write it off as a business expense *coughRCEcough*? Besides, it's less than a set of Konis.

p.s. Subscribed!
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Old 06-21-2007, 11:58 PM   #12
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I think RCE was planning on doing the video thing but with a guy with manboobs from a chase car.
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Old 06-22-2007, 01:18 AM   #13
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Quote:
Originally Posted by strohausii View Post
I think RCE was planning on doing the video thing but with a guy with manboobs from a chase car.
hahahaha.....gotta show this to Myles!


The accelerometer idea sounds pretty good.

- Andrew
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Old 06-22-2007, 07:57 AM   #14
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Quote:
Originally Posted by flyboymike View Post
http://www.sensr.com/gp2.html

How about someone with a suspension business who could write it off as a business expense *coughRCEcough*? Besides, it's less than a set of Konis.

p.s. Subscribed!
Yes, a data logging accelerometer put to use by a vendor with access to various products and a test loop**. The only problem would be that some of the results may hurt sales of a given product, so I duobt any vendors would risk that.

What we need are fact/data gathering meets. Various people would bring various data loggers, and everyone else would bring their modded cars. The day is spent driving the various setups on the test loop logging data and getting subjective opinions as well. The difference here would be that the subjective opinions would be coming from people that drove the various suspensions back to back on the same test loop. Of course, such meets won't be limited to suspension stuff, brakes and engine mods mods could be evaluated as well.


** test loop = any section of road, parking lot, or track that can be repetitively driven over.
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Old 06-22-2007, 09:21 AM   #15
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One of my college proffessors used to work at delphi. To gauge smoothness of an idle, they mounted a bottom weighted needle with a fulcrum in the middle inside an upside down glass globe. They painted the globe @ the top of the green, then 1/8" down yellow, then red, and so on. As the car vibrated, the needle would oscillate causing the tip to dip into the yellow and red sections. Nothing terrible accurate, but good enough for what they wanted.
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Old 06-22-2007, 04:08 PM   #16
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Mythbusters did something this thread reminds me of is whether driving faster over bumps or slower is ..... less bumpy.... To gauge it they used a pyramid stack of champage glasses filled with water and then they measured how much was left afterwards.
It was interesting, but far from factual. My own guess was it was more to do with frequency than anything else.
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Old 06-22-2007, 04:22 PM   #17
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I will be tuning the new suspension with a 4-post shaker and a couple accelerometers here at work. I could potentially post video and data for everyone to look at, but that isn't exactly going to be comparable.



If people want to pool together some money, buy a copy of LMS Test.Lab, a laptop to load it on, a data acquisition board, and some accelerometers I'll travel the country testing whatever suspension setups people want me to!
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Old 06-22-2007, 05:09 PM   #18
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buy a 6 pack of beer/coke.

can #1,2 stays home as the control cans
can #3,4 go in your subaru, one in the drivers and one shot gun
can #5,6 go into your wife/gf's cushy Volvo/BMW/Lexus/etc

drive

open all cans

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Old 06-22-2007, 05:36 PM   #19
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Didn't one of the magazines do a "Grandma Test?"

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Old 06-24-2007, 11:40 PM   #20
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^^^ I think that was Sport Compact Car Mag. Circa anno domini 2002 or 3...
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