Koni Yellow Settings

[Norm Peterson]

How do you ensure that the damping is the same left to right?

Without a shock dyno plot (or your own shock dyno), you probably can't assume anything better than "X" number of clicks or sweeps on will put you in the same place.

How do you get the damping to, say, 65% of critical as opposed to, say, 90% of it?

Don't worry about what the C/Cc number might be.

Are such differences really going to be obvious even when your posterior is secure in the seat?

Obvious if you can notice the right things, which might be easier if there's a rapid sequence of corners that you can become very familiar with. You might find that enough less damping ends up feeling not quite as stuck down (for lack of better terminology) as when the damping is cranked up some. I'd guess that when further stiffening doesn't make the car feel any more stuck down and the car isn't trying to do anything bad, you might as well stop tinkering with the damping adjustment(s).


Curves of ride and performance vs % critical damping should generally look something like this ↓↓↓ . Oddly, P/Pmin is the ride curve and R/Rmin refers to roadholding performance. Note that these curves do not address the use of damping adjustments to solve vehicle transient issues.

If it matters any, with stock springs I haven't felt any need to go beyond 1.5 turns up from full soft up front or +1.25 turns in the rear (Koni yellows). I may try just a hair more front (rebound) damping with the new wheels and tires.



Norm

 

[claudermilk]

Data acquisition is key to this stuff! It's dead-nuts simple to whip up a graph of velocity vs. distance. If you're consistent, the lines from multiple laps will overlap, since you're passing the same point on each lap at the same speeds. If you have a sag on the line in some area for a given lap (passing, being passed or a mistake), it's safe to say that it should be back up to snuff after the next braking zone when you're back up to speed. Once you're getting close on the velocity/distance graph, OR if you're scratching your head as to why it's not close, you can start looking at LatG vs. distance, and LonG vs. distance, and start analyzing where you ARE inconsistent. If you REALLY want to start improving once you have some sort of foundation, pull your "best lap" and "theoretical best lap" and start comparing. TBL essentially looks at all the laps in the session on a sector-by-sector basis, and constructs a hypothetical lap based on your best performance in each sector. This is particularly handy for reinforcing to yourself that yes, you CAN take corner "X" at velocity "Y" and make it stick, because you already did it!

This alone makes this thread worthwhile for me. I have the capability for data aquisition & video (GoPro, RaceChronoPro/Torque/Trackmaster, Garmin GLO GPS, BT OBD scanner), I just need to get down what to do with the data once I have it. This help focus me on what feeds to look at and what to concentrate on first. So, ignore everything except speed vs distance at first, then look at G-loading.

Curves of ride and performance vs % critical damping should generally look something like this ↓↓↓ . Oddly, P/Pmin is the ride curve and R/Rmin refers to roadholding performance. Note that these curves do not address the use of damping adjustments to solve vehicle transient issues.

-snip-


If it matters any, with stock springs I haven't felt any need to go beyond 1.5 turns up from full soft up front or +1.25 turns in the rear (Koni yellows). I may try just a hair more front (rebound) damping with the new wheels and tires.

So as a compromise, where the P & R plots cross is a sweet point it would appear. Now the trick is to figure out where that is without all kinds of expensive test rigs and track time.

 

[Norm Peterson]

Where the P and R plots cross very likely defines the region where OE critical damping lives, and perhaps what you'd try to dial back to after your autocross or track time is done and you're headed home.

Though I think the sort of person who's likely to adjust damper settings in the first place is likely to still skew the settings for a slightly bigger slice of roadholding with slightly reduced ride quality.


Norm