edfishjr

I watched the video linked earlier on using the software to tune the DSC shocks. The capability is really quite amazing. For autocross, being able to tune the characteristic w/r/t 3 velocity ranges should be fantastically useful. If you want a regressive characteristic, for instance, you can get it. (As long as you have a car with ride height sensors.)

If you don't have ride height sensors you are very limited. I need to think about it some more, but I'm having trouble seeing how G-force tuning alone can produce a good autocross setup. Maybe I'm missing something, but without ride height sensors 1) the bump and rebound forces at any particular control point are always going to be exactly the same, which is not necessarily bad, but certainly not normal in our world, and 2) having maximum damping at maximum cornering is never going to be optimal on the bumpy lots we race on.

One thing that occurred to me is to wonder if the absolute value of the shock forces are available for each car? Can we find the numbers so that we can calculate a % critical damping, for instance, if we are used to doing that, so that we can find a reasonable starting point for our particular setup? Seems like having to dyno these shocks would be quite difficult.

abqautoxer

Tested the default rate of 25 and 30 with the G Max Rate set to 0 this weekend. Definitely reduces the more split brain feeling having the G Max Rate to 0 so comfort is always off. These now feel much more like conventional shocks with autox settings so I recommend at least trying this. Not sure if the default rate comes into play at that point at all because I think almost all maps are over 30% so that's probably why I couldn't tell 25 from 30. I'm still only changing the low speed. I'm not sure I can determine at what velocity the shock goes into the medium speed settings. If TPC can shed some light on that and the high speed velocity, it would be useful.

25 Default rate, 0 G Max Rate. Ambient temps were 99F so quite a lot of grip considering:

DR.S

If "g max" is not reached, the dampers are triggered like via the stock controller, all four get the same signal aka "default rate" ?
"default rate" is active till "g max" is reached.
This would mean, if "g max" is zero, "default rate" will not be considered ?
Is the DSC controller capable to be "full active" all the time (cpu power, heat, ...) ?

Please confirm, Tom@TPC

Tom@TPC Racing

Velocity = DSC Suspension Travel Velocity tuning is explained at 36:58 in the software tutorial video.
Travel velocity in inches per second is pretty standard among the motorsports industry.
Video link-

Tom@TPC Racing

If G Max Rate and Sensitivity are not met the command to all four shocks is the Default Rate % value.
The can alter the front and rear command of the Default Rate % by adjusting Shock Calibration for that %.
If G Rate Max is zero then Default Rate does not factor in. This and G Comfort Parameterare explained at 10:29 in my video - DSC is working all the time while you are driving.

David Borden

As I understand it, when setting the G Max Rate to 0, it disables the comfort area and forces the controller into the main G Table 100% so the default rate does not apply regardless of where its set.

The last couple events I set it at zero and made changes to the shock calibration table by softening the overall range for the front and rear shocks and that made a significant difference for the better. I made adjustments between the front and rear calibration table ranges, softening the front and stiffening the rear and it helped dial out some of the understeer. I still have more to go with this as I would like to rotate the car while on and off the throttle and its not there yet. It seemed using the stiffest part of shocks range on the GT3 reduced grip in autocross and cost time with my current tires.

I want to experiment with the velocity tab, but I have concerns that hysteresis will come into play as the controller will be commanding shock adjustments mid stroke at different velocities and the shocks wont be able to keep up. It would be good to know if it is effective or not with our cars OEM shocks... or if we should just leave it alone. We don't need to know reverse engineering data, just assurance that it functions as one would assume... or suggestions on how to get the most out of it given the limitations of the factory hardware.

sgreer78

IIFC, you have your front bar soft and rear stiff. I'm not sure that's the best way on this platform to do what you want. With the bar soft, you could be very well overloading the front outside tire too fast and that will cause the car to push. I went a different route and found the car to be much freer and predictable. YMMV of course.

abqautoxer

The velocities tab is primarily the only thing I'm changing. So far I'd call it subtle change but measurable. Definitely change at 10% values until you get close. As for lag, I noticed most of the med/high speed is already set close to what I'm now moving the adjustments towards in rebound. Compression I'm going the opposite way but not by a lot.

David Borden

Interesting. Ive never had a car that was not camber limited push more from softening the front bar. Have you experimented with that? I wonder what is actually happening that would make it do that, as that is the opposite of what I would expect it to do.

abqautoxer

I have, it depends how you drive and if you really are on the limit on entry (dive bomber). Then factor in some tires really hate slip and you overwhelm them fast like the RE71R.

abqautoxer

New version of DSC tuner software out there. Tom@TPC just a thought, might be best to use the subscription to send us the new link rather than the way it plays out having to unsubscribe/resubscribe or give you another email address.

daaa nope

So you guys are running this for Autocross now - last I saw, the DSC box was banned from "Street" class.

Has that changed? I have a 718 Spyder coming in a few weeks and will be running the car in SCCA Super Street. If the DSC box is legal.... I'll be ordering one.

abqautoxer

It's been legal in SS for awhile...

David Borden

We had another two day event this last weekend and the made a few more changes to the DSC tune. For Saturday, I tweaked the previously saved file the evening before and then pushed it to the box after two runs(we got five runs) to get a back to back comparison and the result was very positive. This time I only tweaked the velocity tables. It appears that DSC tweaked the adjustments to soften the front turn-in a bit to make the car safer quick wheel inputs at higher speeds. I reversed that a bit and the now the car has virtually zero understeer, and will continue to rotate on throttle. Its very different from before and its is much better suited to my driving style. The results wont be up for a bit, but I believe we did reasonably well. I will post the results when they are published.

Here is a video of my fastest run on Sunday.

abqautoxer

Glad you found something that is working. I think we have enough baseline info to change the car measurably so it's just a question of suiting it to your car and preference.

Off topic, that's two courses you've shared from that site that are basically just 4 drag strips. You could get away with a very loose car there and not pay for it much.