S.A.S.C.
Solo => Technical Talk => Topic started by: MurrayPeterson on January 31, 2018, 11:04:24 AM
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Spent the money and got some custom valved double adjustable Konis.
I'll need some help learning how to twiddle that extra dial (compression settings). And probably spend all year figuring out a good setup for the car :(
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Good move! They will make a difference!
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Congrats on the new toys!
Did they provide force-velocity plots of the adjustment range too? F-D plots will show more of the quality/consistency of the dampers, but the F-V plot is what you'll need to figure out a baseline to start from.
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Nice Murray!
Congrats on the new toys!
Did they provide force-velocity plots of the adjustment range too? F-D plots will show more of the quality/consistency of the dampers, but the F-V plot is what you'll need to figure out a baseline to start from.
I got some custom valved koni's this year also and Truechoice told me that since they dyno the shocks on a mechanical dyno they only have an F/D plot and no F/V plot available. So all I have to compare is the before re-valving and after re-valving plots.
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And probably spend all year figuring out a good setup for the car :(
If ProParts did the revalve good chance Jeff Wong did the work.
He would be a good source for baseline.
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Yes, Jeff Wong was the guy. I have asked him about a baseline, but he is being "cagey" :) It appears that the ND has a wide range of preferred settings, so he really doesn't want to commit to any official statements about setup.
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Usually they valve the shocks so that the "ideal" (or their estimate) is right in the middle range of the adjustments. So that would be a good starting point.
My Penskes from Guy Ankeny were just about perfect exactly in the middle where he valved them .... He did an excellent job.
R
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It seems Santa was kinda to you good boys last year.
Here i was excited that i may be returning with new wheels ;D ;D ;D
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Murray, if you can, I would ask for the F-V plot or the raw data from the dyno runs. They advertise that they test on a Roehrig shock dyno, so they should have the data file.
From there, if you search the web or measure for yourself, your corner weights, unsprung weights, spring rates, and motion ratios, you can approximate what your theoretically ideal damping curve looks like for maximum traction. From there you can compare it to your shock dyno results to validate where in the adjustment range that falls.
You'll still need to test. On soft OEM springs, and only 2-way adjustable (compared to 3 or 4-way), you'll be trying to find the compromise between stiffening the low speed damping to control roll/pitch body movements without sacrificing too much traction from the resultant increase in high speed damping. But if you start getting lost in the compromises, at least you'll have a point of comparison.
Agreed that most shops would be putting that ideal curve right in the middle of the adjustment range, but it's nice to validate that. Especially if the front and rear shocks ended up with the same valving, the "ideal" setting will need to be different an each axle (ie. with the same Koni 8241 model front and rear, there might not be enough resolution between shim thicknesses to use different shim stacks)
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Murray, if you can, I would ask for the F-V plot or the raw data from the dyno runs. They advertise that they test on a Roehrig shock dyno, so they should have the data file.
From there, if you search the web or measure for yourself, your corner weights, unsprung weights, spring rates, and motion ratios, you can approximate what your theoretically ideal damping curve looks like for maximum traction. From there you can compare it to your shock dyno results to validate where in the adjustment range that falls.
You'll still need to test. On soft OEM springs, and only 2-way adjustable (compared to 3 or 4-way), you'll be trying to find the compromise between stiffening the low speed damping to control roll/pitch body movements without sacrificing too much traction from the resultant increase in high speed damping. But if you start getting lost in the compromises, at least you'll have a point of comparison.
Agreed that most shops would be putting that ideal curve right in the middle of the adjustment range, but it's nice to validate that. Especially if the front and rear shocks ended up with the same valving, the "ideal" setting will need to be different an each axle (ie. with the same Koni 8241 model front and rear, there might not be enough resolution between shim thicknesses to use different shim stacks)
Note that for autox you are allowed a maximum of 2-way adjustable shocks. 3-4 or more way adjustable are illegal. It's in the rules.
R
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Murray, if you can, I would ask for the F-V plot or the raw data from the dyno runs. They advertise that they test on a Roehrig shock dyno, so they should have the data file.
Done that, and waiting for a response
From there, if you search the web or measure for yourself, your corner weights, unsprung weights, spring rates, and motion ratios, you can approximate what your theoretically ideal damping curve looks like for maximum traction. From there you can compare it to your shock dyno results to validate where in the adjustment range that falls.
You'll still need to test. On soft OEM springs, and only 2-way adjustable (compared to 3 or 4-way), you'll be trying to find the compromise between stiffening the low speed damping to control roll/pitch body movements without sacrificing too much traction from the resultant increase in high speed damping. But if you start getting lost in the compromises, at least you'll have a point of comparison.
Agreed that most shops would be putting that ideal curve right in the middle of the adjustment range, but it's nice to validate that. Especially if the front and rear shocks ended up with the same valving, the "ideal" setting will need to be different an each axle (ie. with the same Koni 8241 model front and rear, there might not be enough resolution between shim thicknesses to use different shim stacks)
Unfortunately, I am getting these shocks to provide me with settings that are well outside the "ideal". I ordered them with a healthy dose of extra rebound, and plan on using that to control the body roll in corners. I can then soften the front roll bar and front bump stops, which will help solve the mid-corner understeer. The joys of street class, where one has to do silly things to get around issues that are solved easily in street touring :(
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The joys of street class, where one has to do silly things to get around issues that are solved easily in street touring :(
Sounds like you just need to go to Street Touring, then. ;D
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Ahh, but street touring comes with two penalties; cost and street driving enjoyment.
Our Miata is our touring car, so something that is noisy and/or harsh just won't be acceptable. As for handling, I drove a very lightly prepped STR ND at the school in Fort Macleod, and the car's handling was amazing (perhaps even astounding). Full throttle in mid-corner induced no understeer, even on pin turns. And trustworthy handling at any speed. Problem is, full prep gets into headers and exhaust that is irritating (at the least) when travelling.
As for cost, well, I am retired. That means a lot -- no more money coming in to the bank account, ever.
Got the F/V plots for the shocks (attached). Notice that the compression in the rears is quite a bit softer -- this is done to make for a car that is driveable on the street.