Tom@TPC Racing

Steering table is usually not used on modern production sports cars. Steering table is commonly used on front-engine muscle cars with very heavy front weight bias. And for cars with very soft sway bars or no sway bars. For cars with decent sway bars adding damping force via Steering table can increase understeer.

Acceleration table is usually for cars with large displacement engines such as Corvettes and Vipers.

With the DSC tuning software DSC users can experiment with these tables to see for themselves whether or not they like the results.

slicky rick

hi Tom,

ive been experimenting with my dsc tables and i feel i am getting close to where i would like my suspension to be for our kind of roads...
however, may i ask, where in our software is bump and rebound stiffness adjusted ? is this a constant function base on the shock calibration table?
also, i might have missed it, in the speed table there is a "Speed G-limit threshold" is this like gmax in our comfort table? g's below the threshold, the speed tables are in effect. At g's above the threshold the main G table is used. Should this value be at least equal or less than the G-max in the comfort parameter.

slicky rick

just saw you link to the dsc manual and saw the answers... good to know that the percentages that are indicated on the speed table are actually added to the percentages set at at gforce table when the speed is reached and below the speed g limit.

Tom@TPC Racing

Using DSC software not only can Compression(aka Bump) and Rebound be adjusted interdependently they can also be adjusted for the level of load in the G Force table, Brake table, *Accel table, **Velocity, and Speed table. Unlike conventional passive mechanical adjustable dampers, DSC does Compression and Rebound adjustments dynamically and multi-dimensionally!

Here is an example in the DSC G Force Table-
Referring the cell highlighted in Blue color, the user must understand the basics of how any G Force table(or G Force circle) works, in this example, the highlighted cell shows the damping commands at 0.4g of straight line braking. Inside the cell are four numeric values, each value is the command for a specific damper(Left Front, Right Front, Left Rear, Right Rear). The user must also understand basic vehicle dynamics in that during straight line braking the vehicle dives, thus the front dampers are on Compression stroke and the rear dampers are on Rebound stroke. In this particular example, the DSC damping commands are 50% Compression for the front dampers and 60% Rebound for the rear dampers.

Of course DSC users can adjust these values to suit their personal preference for their usage; Let's say for a daily commute there is a traffic intersection that is very bump. The user can reduce the front compression by 5% or 7% or 10% respective to the nominal g force range for braking at this particular traffic intersection. The user can reduce front compression before making an adjustment to the rear rebound or the user can adjust both at the same time. In addition to these adjustments the user can also modulate the braking pressure at the brake pedal to trigger different damping commands on the fly.

Here is an example of the DSC Brake table showing damping commands of 11.5% Compression(to front damper) and 7.0% Rebound(to rear dampers) at 10 Bar of brake line pressure.


Again, DSC users can make adjustments such as for tracks with bumpy braking zones and for brake pads with very aggressive initial bite(some carbon ceramic type brakes for example). The tuning possibilities are endless with DSC. Please keep in mind that the limitation is in the OEM PASM dampers in its response time, peak damping force, ability to react to commands during mid-stroke, and responds better on rebound stroke than compression stroke. Despite of these limitations DSC users can still do A LOT with OEM PASM dampers. Side note: Tractive DDA dampers do not have these limitations.




Denotes:
* Accel table is not used in standard DSC maps for all vehicles. Can be utilized by DSC users.
** Velocity table is not available for all vehicles. Vehicle must be equipped with four appropriate ride height sensors and associated hardware.

Croc999

Tom, this is a good insight.
Is it possible to calibrate separately compression/rebound at Zero G situation? I mean going straight at steady speed and hitting bump/dip.

Also - is there a way to tune high/low speeds separately?
So far i've used shocks table to kind on mimic that assuming higher G is equal to higher shock speed - which is probably is not 100% accurate but it kinda did the trick.

Tom@TPC Racing

Yes, in the Speed table for 60mph and above. For newer cars(981/991) that are equipped with four ride height sensors feeding data to the CAN bus there is the Velocity table which is has active 6-way function(High, Medium, and Low speed for Compression and Rebound).



For earlier generation cars without Velocity function, such as my personal car, a 997.1, the combination of Shock Calibration and the G Comfort Parameter has been extremely effectively for improving ride quality over bumps and dips. Hundreds of 9x7 DSC users on this forum alone can attest to this.



The answer is no for cars without four ride height sensors on the CAN bus. Which is not at all show stopper considering all 997 GT3 Cup and 991 GT3 Cup race cars have none-adjustable shocks from the factory. Your tuning approach is effective and we applaud you for using the DSC software to tune for success! Your experience yet again has proved that even without Velocity function a lot can be done with the DSC. We have 9x7 cars going blazing fast with DSC, Tractive dampers, and TPC setup.

kpl

being one with PCCB's on my '11 TTS, what would your recommendations be for modifying the setting for both normal (street) and sport modes (AX/track)?
Thanks,

gasongasoff

For street driving, what are the limits for the 3 values above?

Tom@TPC Racing

What I recommend is that if you are not having a braking issue then leave it alone since the braking action is within the control of the current mapping. Most drivers do adapt to a braking threshold and it becomes a muscle memory.

In the rare cases that the brake pads are "too bitty" for the tires then reducing the percentages in the Brake table and upper section of the G Force table does help. Using this chart below purely as an example-

The Red and Green torque profile will benefit from soften front compression when there isn't optimum tire grip for braking.

Tom@TPC Racing

As far as making changes to the DSC software is concern,

Default Rate can be from 1% to a percentage that is less the minimum percentage in the main G Force table.

Sensitivity at 15 to 35.

G Rate Max at 20 to 40.

These ranges are logical on paper(or on computer screen). However, the actual feel of running on the far end of the range for comfort might make the car cushy for some, while other might like it. All subjective to personal preference at this point.

slicky rick

The speed table has been very effective for me in improving the drive character of the car at speed...

ralphmusic

My question is about the (Transmission) Mount Calibration table and how to use it.

I have a 981 Cayman with a 3.8L engine and Damptronic dampers. I want to see if I can use DSC to stiffen the mounts during direction changes (latitudinal load transfers)

The Mount Calibration table values range from 500ma at 0% to 2000ma at 100%.

First, is this range the full range for the OEM mounts?

Secondly, the Shock Calibration table values range from 1500/1400ma at 0% to 600/400ma at 100%. Why are the higher/lower value reversed Mount to Shock tables?

Will the DSC box affect the transmission mount behaviour?

Tom@TPC Racing

Yes, DSC maps out the percentage of stiffness of the mounts to the amount of g-force and the direction of g-force, and can have different values for Normal and Sport mode. Example in image below at 1.0g lateral.


Yes.

The Dynamic mounts are Magnetorheological fluid operated. Whereas the PASM/Damptronic shocks are shim stack & valve operated. One defaults at full soft at zero current, while the other defaults at full stiff at zero current. The same "reversed" current application can be found on DSC mapping for cars with Mag fluid shocks such as Z06 Corvette, ZL1 Camaro, and GT350 Mustang.


Technically the transmission mount on a 981 is the engine mount since the engine is flipped around the other way compared to a rear engine car. So the answer is no, DSC does not control this mount because this mount is not electronic. The mounts circled in the image below are electronically controlled.

ralphmusic

Thanks for the quick response on Mount Calibration

ralphmusic

A couple more questions...

First,
Most of the discussion is on 997/991 platforms. Are there any material differences for 981 vehicles? e.g. I presume weight transfer on braking and hard acceleration is different due to the different static front/rear weight distribution, but DSC standard files are common to both 991 and 981

Also,
My 981CS exhibits some lateral rocking motion (seemingly more from the rear) under a couple of conditions:
After a 75mph right whilst accelerating through an immediate left to 95mph and keeping to the left for a 45mph right, and also
though a 70mph rising to 100mph left/right/left.
This is using the standard sport map values except that 0% and 100% Shock Cal values are reduced by 100ma and auto filled between
Any thoughts on what mapping changes I might try to dial this out? - I'd prefer not to slow down...