DSC Suspension Controller - tuning and talk

[rayzazoo]

Thanks Ray! I got done with my part of a major home project Friday. That is going to allow me to get into this now. I am fired up because my car really feels good! We took a 500mi round trip with the Durango. I want the Durango controller also, it rides like a truck with sharp rebounds and feels bad now. Wow.

I know at this point anyway several things..
- it is not the DS unit at all and seems to have almost enhanced different and fundamental control.
- whatever the settings are in Sport Mode from the neutral ride to how it then behaves, I am going to like to make those settings my street (default).
- I have done a couple of these 90 degree bends also. Besides the perception you describe about firming up the sway dramatically, I have a 90 with a downward hill also. It makes that turn fairly aggressively (fast), and besides this more stable feeling the tires are silent!

@rayzazoo I need to understand a lot more around which screens (settings) and how we are entering the numbers. In the short time I viewed the “tune” downloaded from the car, I don’t see anything but blank entries, except for the first screen that has the % shock values and the acceleration screen. I have until Oct 17 before putting it on the track at RA, to play with the Track settings, and then want to understand the system so depending on how she works I can make some changes on the fly.

Can I ask for some help to better understand where, how and what is going on with the mA settings? Where are the fundamental rebound settings, or as we increase these is all that taken care of either to a lessor or greater degree? Let me know if you can help. I am also going to watch all of their tutorial library today. Hope to be smarter soon.

Surprisingly, most of my adjustments are on the accel table. I think the brake table is already good. There are only 3 mA settings on the shock calibration table. You could go progressive but it'll result in softer vs. 3-button and suspension scenarios.

I spent most of the time understanding the 400, 200, and 100 mA transitions between accel, gForce and speed tables mainly to eliminate large transitions between tables. That resulted in the following.

Sport Accel Table:

10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold 1300

Track Accel Table:
10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold 1500

It's a starting point and would recommend datalogging by routing a long USB cable from the rear to the front passenger seat with a computer.

 

[DGatzby]

Surprisingly, most of my adjustments are on the accel table. I think the brake table is already good. The main thing is there are only 3 mA settings on the shock calibration table. You could go progressive but I think it'll result in softer vs. preferred firmer scenarios.

I've got a longer USB cable being delivered so I can datalog.

As a starting point. I spent most of the time understanding the 400, 200, and 100 mA transitions between accel, gForce and speed tables mainly to eliminate large transitions between tables. That resulted in the following.

Sport Accel Table:

10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold 1225

Track Accel Table:
10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold 1225

The tutorial helped me. Let me get into the numbers and even write some stuff down so I can talk smarter.

 

[covidcommander]

Thanks for sharing all this. Definitely happy with mine. Made the car feel much more refined and planted in turns and straight line acceleration. Actually let's me get traction earlier on the street. Awesome mod. Definitely feel the difference

 

[DGatzby]

Okay! I have a much better lightened schedule now. I have been driving it around. I cannot wait to go and run some laps at RA. I think it is different. It’s more flat in turns, I have done a few round-abouts and especially leaving them, to try to gauge what feels much more smooth as @rayzazoo also noticed, since we have several of these interesting things in rural MN.

It seems to transition much better.

For some reason it really loosened my rear end, maybe in a more predictable way. I’ll need to get the sticky track tires hot and see what we may have here. It can absolutely toast those PS4S rollers the way it is set up in those corners. But it seems to bite down better leaving a corner or just accelerating forward.

After all that…I only changed the comfort setting in Tour Mode. Loved Sport with the 18 comfort. Set it to 23 now, and lowered Tour to 20. Just went for an evening drive. Feels like grandma maybe would like the ride! I’ll try this for a while.

Driving in default (Touring) is most comfy. Then it also is comfy past the point where Sport and Track begin to firm up. I am not sure I can tell that difference.

The big pisser? Now the Durango needs one!! It rides like a damn truck, shit! After driving this car all your shit feels like a truck it is so incredible refined. I know why they told me the Durango controller makes a big difference now.

 

[rayzazoo]

@DGatzby

After datalogging (routing long USB cable to a computer in the passenger seat), several road tests, driving impressions, turns, accounting for suspension settings etc, below is what I ended with in the 0-60mph acceleration table. The accel table made launch suspension transition more controlled and created more control/confident throttle in acceleration turns <60mph. I took the datalogs and dumped them into ChatGPT which substantially saved time on the suspension analysis.

Similarily, I've been analyzing thermal load management and track layouts.

@DGatzby, with Road America coming up in October, I did a track analysis based on your setup along with multiple other variables added.

Also a recommended baseline based on your setup.

Sport Accel Table
10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold: 1300 ms

Track Accel Table
10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold: 1400 ms (Michelin PS4S); 1350-1400 (R888R)

Preserve the existing G-force table

At a minimum, an interesting read to compare to what you've already experienced.

 

[DGatzby]

After datalogging (routing long USB cable to a computer in the passenger seat), several road tests, driving impressions, turns, accounting for suspension settings etc, below is what I ended with in the 0-60mph acceleration table. The accel table made launch suspension transition more controlled and created more control/confident throttle in acceleration turns <60mph. I took the datalogs and dumped them into ChatGPT which substantially saved time on the suspension analysis.

Similarily, I've been analyzing thermal load management and track layouts.

@DGatzby, with Road America coming up in October, I did a track analysis based on your setup along with multiple other variables added.

Also a recommended baseline based on your setup.

Sport Accel Table
10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold: 1300 ms

Track Accel Table
10-80% is 50.0 LF/RF and 20.0 LR/RR
Launch Start 50.0 LF/RF and 20.0 LR/RR
Launch End 50.0 LF/RF and 60.0 LR/RR
Threshold: 1400 ms (Michelin PS4S); 1350-1400 (R888R)

Preserve the existing G-force table

At a minimum, an interesting read to compare to what you've already experienced.

Wow! I printed it all out. I will dive very carefully into it. I believe it says try their Track mode first, before trying anything. I did read some of the analysis. We use a 12” wide x4 Triumph wheels. 325/30 Cup 2 (f) and 335/30 Cup 2R (r). As the track day dress right now. I see they now produce the 345/30 in a Cup 2R. I need to evaluate if the more equal 325-335 setup works. I have not convinced myself this car handles better with any rubber stagger yet, and I cannot get any larger tires up front.

That is an excellent technical discussion of the track, thanks! I have read and seen a few.

Entertaining to see the speed the BOT thinks we can do thru the carousel. I have never been faster than about 72 in there. Right there is where I will see if we can get more speed. The Vettes and real track cars pound thru there at 80 and more. We do use the infamous Kink. I look at it much like any big sweeper myself, so I know the Hellcat has amazed them thru there (120 entry-80 exit then on the throttle. Horsepower and your nut sack rule... the RE can be the first to Canada Corner if we want.. Then like in the video I often post, not many pass the Dodge until the next lap after Turn #5. They may bunch up behind btw Canada Corner etc. but there is no way around @ neither the main straight or btw turn #3-5 generally are tough places to get around the Dodge unless allowed. IF I see anything that is on my ass at #3, that means they are definitely serious & faster and need to get around my heavy ass, I will allow a pass, there or btw 1-3 also, as I can still maintain plenty of speed until #5. And it is always fun to play the throttle when I allow a pass btw 3-4, to see just how much power others have. Thru the Kink and down to Canada Corner you MUST relax! The first time I used the DS controller at RA this area is where more high speed stability was CLEARLY present. Speeds are nuts, (the old surface was a rock and roll nerve test all at well over 100 mph) and the consequences are severe damage or of course worse.

 

[rayzazoo]

Wow! I printed it all out. I will dive very carefully into it. I believe it says try their Track mode first, before trying anything. I did read some of the analysis. We use a 12” wide x4 Triumph wheels. 325/30 Cup 2 (f) and 335/30 Cup 2R (r). As the track day dress right now. I see they now produce the 345/30 in a Cup 2R. I need to evaluate if the more equal 325-335 setup works. I have not convinced myself this car handles better with any rubber stagger yet, and I cannot get any larger tires up front.

That is an excellent technical discussion of the track, thanks! I have read and seen a few.

Entertaining to see the speed the BOT thinks we can do thru the carousel. I have never been faster than about 72 in there. Right there is where I will see if we can get more speed. The Vettes and real track cars pound thru there at 80 and more. We do use the infamous Kink. I look at it much like any big sweeper myself, so I know the Hellcat has amazed them thru there (120 entry-80 exit then on the throttle. Horsepower and your nut sack rule... the RE can be the first to Canada Corner if we want.. Then like in the video I often post, not many pass the Dodge until the next lap after Turn #5. They may bunch up behind btw Canada Corner etc. but there is no way around @ neither the main straight or btw turn #3-5 generally are tough places to get around the Dodge unless allowed. IF I see anything that is on my ass at #3, that means they are definitely serious & faster and need to get around my heavy ass, I will allow a pass, there or btw 1-3 also, as I can still maintain plenty of speed until #5. And it is always fun to play the throttle when I allow a pass btw 3-4, to see just how much power others have. Thru the Kink and down to Canada Corner you MUST relax! The first time I used the DS controller at RA this area is where more high speed stability was CLEARLY present. Speeds are nuts, (the old surface was a rock and roll nerve test all at well over 100 mph) and the consequences are severe damage or of course worse.

It'll be great to analyze the datalog data. For datalogging, recommend a 15ft USB to mini cable. I started with a 10ft and had to add an extension. I ran the cable along the trunk driver side, then under the backseat to the center armrest console. Then laptop with DSC software in the passenger seat. Always have to have the car at least in Run mode before plugging the USB into the computer.
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It's interesting to see the bot results and ore below to digest from your feedback. Simarily, I'm running thermal management comparisons and quite surprised by the amount of math it's referencing and calculating.

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His current configuration is not merely a 10 mm stagger—the Cup 2R rear versus Cup 2 front is an additional grip stagger. Moving to a 345 Cup 2R would further increase rear grip without adding front capacity.

That could help acceleration from:

• Turn 3
• Turn 5
• Canada Corner
• Turn 14

But it could hurt rotation or front-tire workload in:

• Turn 1
• Carousel
• Kink approach
• Canada Corner entry

Because his present limitation is approximately 72 mph through the Carousel, rather than exit wheelspin, the 345 probably does not address the current bottleneck. I would retain the 335 until data demonstrates rear slip under power.

Revised Road America DSC plan

1. Keep Track mode and the existing 1,500 ms threshold.
2. Run the 325/335 setup exactly as currently configured.
3. Establish real speeds and G-force at every major corner.
4. Concentrate analysis on the Carousel, but do not change damping at the Kink initially.
5. Log:
   • All four wheel speeds
   • Steering angle
   • Lateral and longitudinal G
   • Yaw rate
   • Throttle position
   • Brake pressure
   • DSC commanded damper currents
   • Tire pressures and temperatures after the session

Carousel target

His actual 72 mph becomes the baseline. The next objective should be repeatable 74–76 mph.

If steering angle increases while lateral G stops increasing, the front tires are saturated; adding rear tire will not help. If yaw oscillation or rear slip appears, DSC or rear grip becomes the relevant adjustment.

What we learned

• Track mode’s high-speed damping is already delivering a real stability advantage.
• More horsepower is not the limiting factor at Road America.
• The Challenger’s time loss is concentrated in sustained and transitional corners.
• A 345 rear is justified only by demonstrated power-down limitations.
• The first improvement should come from line, tire temperatures, pressures and front grip—not another rear-width increase.

His feedback makes the 325/335 setup the better baseline. Preserve the controller’s proven Kink stability and use the Carousel to determine whether the next constraint is front grip, chassis balance or driver confidence.