Tom@TPC Racing

Velocity tuning is an offset value(as per description starting at 36:58 in the video) to the primary load value(which is G-Force) within the capability of the OEM dampers. Damper tuning in pro racing is typically considered fine tuning of the chassis. As in, in order of things, the rest of the mechanical adjustments of the car has be pretty balanced(or "in the zone") before make damper tuning changes. For a much more pronounced change in chassis balance tuning we change rake, sway bar setting, and alignment. For example if the car has lot of push, dropping the front height by 3-5mm tips the balance scale to have more front grip overall, which could also have more rear rotation but that can be favorable for AutoX.

As for which setting is best, I am sorry I don't have an answer to that question because there are more than one approach to chassis tuning based on driver's input and other external condition factors. Just have to try thing out. If you find that by using a 30%(or greater) value anywhere in Velocity helps but its still not enough, then you need go beyond fine tuning and consider the more pronounced items.

abqautoxer

Changing the rake and alignment isn't available as an option on site for an autox on a surface we might run one time a year, in a 3 run per day format. Even my two local sites are so different that the rear sway bar from full soft to full stiff isn't enough and again the issue is primarily transient more so than steady state. Thanks for the feedback.

David Borden

@Tom@TPC Racing you bring up a good point and something I have been wondering about with regards to hysteresis and the factory shocks with the DSC box. This is one reason I thought to disabled comfort mode the first time I made changes.

Can you tell us what milliamp range the factory controller keeps the stock shocks on a given car in sport and normal mode? This will tell us where the factory has determined the correct damping for the given spring rate, sprung and unsprung mass.(critical damping?). Does the factory controller use the full range of shock adjustment or a small portion of it?

Things happen much much faster in autocross relative to road racing so I am wondering if we want to limit the range of adjustment the DSC box works with to reduce hysteresis or limiting the range of adjustment on the shock through the calibration tab. During the last couple events I did this in shock calibration as I am new to your software and did not have much time... and that worked fairly well.

With that said, I wonder if making changes to the other tables by limiting the range of adjustment the DSC box can make would be better? Basically to reduce the time between DSC sensing a change either through Gs or ride height sensors, commanding a valving change and then the shock reacting and making the valve adjustment. For example, having a tables range be 40-80% vs 1-100%.

Keep in mind, I am only talking about these adjustment theories for autocross. Throw out ride comfort, street, track, etc.

How long does it take for the DSC box to detect a change, say from the ride height sensor, to the stock PASM shock going from 1500ma to 500ma, or full open to full close ? How about from 1200ma to 700ma? What I am looking to learn is at what point is the delay, or hysteresis a problem or hinderance(if at all). For example, directional changes in a slalom or making throttle adjustments to rotate the car in a sweeper? How about stabbing the brakes? How long does it take before the brakes have been applied to the shocks hitting the commanded adjustment? These answers would determine how I would go about using your software. I suspect one could get into the situation where the shocks can not keep up with commands and never hit their mark

Are the strut and valve internals(outside of valving) of say a 718 Cayman with PASM and a GT4 or GT3 the same and react the same?

Clearly, your tractive dampers are better suited to the quick adjustments. With that said, in SCCA, we must use the factory shocks, so they are not an option at this point so it would be good to learn the best way to tune given their limitations with autocross and the quick transitions that occur.

Any light you can shed on these questions related specifically to the struts Porsche uses would be greatly appreciated!

Tom@TPC Racing

Perhaps consider what I suggested earlier, to stiffen the base value to stay ahead of stock damper's hysteresis(aka dead time).

abqautoxer

Thanks I'll test 25% and 30% then and see how it goes.

DR.S

I guess David brings up some good questions but I do not see answers ?!

sgreer78

When you say minimum damping command, are you referring to the calibration tab and making the soft end of the shock stiffer so there's a more narrow window? I think this has been asked, but maybe in a different way.

I'm not blown away by the "touring" file for the 991 GT3 the same way I was by the GT4 file. The car seems a bit floaty and pretty unforgiving. For ****s and giggles I loaded the GT4 cailbration and velocity numbers in and gave that a whirl; did not like. Too soft.

Thanks

Tom@TPC Racing

There's more than one approach.. the G Comfort Parameter can be made stiffer by raising the Default Rate, or by adjusting the Sensitivity/G Rate Max to trigger out sooner, or turn off G Comfort Parameter, or shorting the low end of Shock Calibration, or any combination of the fore. This is the same answer from before just worded differently.

abqautoxer

Rewatched the video a few times and now I'm thinking would it just make sense for those of us that only use the Sport mode for autox to just turn sensitivity to zero? This way there is no chance for lag from g comfort mode and then start fine tuning with the default rate for baseline stiffness?

Tom@TPC Racing

^ I'm not in a position to tell people what to do in an open forum. I have gently implied. More than once, I think.

abqautoxer

Isn't that what vendors do? usually with a caveat. Beating around the bush is actually more confusing judging by the back channel conversations I've had about DSC with many users across a few car types now. Regardless, thanks for the info.

Tom@TPC Racing

Please allow me to express the following. Suspension tuning is a black art. There are many external factors and variables that affect the outcome so there usually is not one general answer that is good for all scenarios. Pro suspension setup personnel charge ~$2K per day for their service to tune the same car for ever changing external conditions. I am using my personal account and on my own will to try to help out when I am not crazy busy with work. I have no obligation to post on public forum. Even professionally, it is not my job to teach suspension tuning, there are many books and online courses for that. I make suggestions as an enthusiast and in hope that some of the info can be useful and possibly lead to a positive result. Gratitude is not necessary but appreciated on my end.

abqautoxer

I get that. The problem isn't suspension tuning, you keep saying that like we don't know how to do that with conventional shocks. The issue is the DSC software and hardware that is unique. There is no G comfort, sensitivity, etc in conventional shocks and what we are asking and apparently doing a poor job of expressing is how to understand how they work and the other settings to align to what each of us know with conventional suspension. My comments aren't meant to be rude but remember, there are several of us who have emailed and gotten no response from the company and you posting is our ONLY method of working with anyone from DSC that can give accurate answers. I don't think its unreasonable to ask for guidance when it comes to DSC unique settings like the gforce tab, and confirming things like the velocity tab really work exactly like conventional shocks, then the generalization of understanding how the PASM shocks work in terms of speed/reaction which is not unique to DSC but you obvious have more experience than most. We appreciate your insight that no one else really can give.

Tom@TPC Racing

Forgive me for coming across in a negative manner. Yes, I suggest to try turning off G Comfort Parameter or adjusting it to trigger out sooner to see if it is better for some AutoX layouts. There are DSC users who are local to me who run regular FTDs using DSC standard calibration. Completely course layout dependent and external conditions dependent. If the dampers feel too soft when at >1.0g during its probably reaction time from OEM dampers so tuning off G Comf seems to me like a sound approach to try.

abqautoxer

I'll give it a shot. I'm going to use the previous velocities I preferred over the default 718GT4 config that worked but set the g max to 0 and default rate to 25 from the base settings. I'll report back. Thanks again.