Review: APR SCU (DSC Controller)

[2019 Golf R]

Installed the APR SCU on my mk7.5 R on Sunday. Have to say that it works very well. The shocks now feel much more "relaxed" in comfort mode and the pogo effect of race mode has all but gone away too.

Brake dive is gone, turn-in is improved and the car stays flat.

You don't see a ton of reviews on this on the forums so I wanted to post one here. If you have DCC on factory dampers and springs this controller is a great option.

Happy to answer any questions. I didn't change the base map since i'm on factory dampers and springs. I didn't test out Comfort vs. Normal mode, only Comfort vs. Race and found both to be a nice improvement.

EDIT: The DSC Controller failed after 3 months - APR has provided a full refund.

 

[yakboyslim]

Definitely check out comfort vs normal - and do you have a OBDeleven/VCDS? It seems at least certain gateway versions do not work in comfort mode (your comfort mode may actually just be normal as well).

Also, if you ever get the urge to deep dive on tuning the controller, I did a fair bit of work on making tools to log and tune with before I sold mine, and would be willing to help answer questions. I would recommend for sure to change the base map by zeroing out the entire acceleration table except for the launch portion (zero the parts based on pedal position). DSC even recommends not to use this table now that they have introduced the launch control tables. It appears they removed the function that would fade the influence of this, so now rather than being a preemptive factor, it just makes the car too stiff whenever the pedal is pressed. Trust me, setting all of that to zero will make the car even better.

 

[Cuzoe]

@yakboyslim Somehow I missed that you were selling yours. You were the only reason I had my eyes (half) open for one on the used market, haha.

 

[yakboyslim]

Yeah, gateway stuff is beyond my knowledge, and when it started giving me AFS headlight errors I was out. To be fair to DSC that problem only came up after I installed my aftermarket headunit, but the OEM DCC controller doesn't have the same problems, so I gave up on the DSC. It's cool for what it does, but I'm convinced that the fact that it doesn't communicate on CAN will always cause problems. I'm also leaning more towards a dedicated track build so coilovers make more sense for me anyway.

 

[erim86]

Yeah, gateway stuff is beyond my knowledge, and when it started giving me AFS headlight errors I was out. To be fair to DSC that problem only came up after I installed my aftermarket headunit, but the OEM DCC controller doesn't have the same problems, so I gave up on the DSC. It's cool for what it does, but I'm convinced that the fact that it doesn't communicate on CAN will always cause problems. I'm also leaning more towards a dedicated track build so coilovers make more sense for me anyway.

please pardon my lack of knowledge on this. you say 'the fact that it doesn't communicate on CAN'. so how does it communicate with the dcc suspension system to do real-time adjustments?

 

[Cuzoe]

please pardon my lack of knowledge on this. you say 'the fact that it doesn't communicate on CAN'. so how does it communicate with the dcc suspension system to do real-time adjustments?

It communicates to the dampers (directly connected, as this takes the place of the factory DCC module). But it does NOT provide the additional communication to the other systems on the vehicle that ARE provided by the DCC module.

Essentially the the APR/DSC module is receiving inputs (from the various sensors on the car) and controlling the dampers, but is not providing any other outputs.
(or more accurately just not providing some/all responses the other car systems expect from the DCC module)

 

[erim86]

i knew that the apr/dsc module replaced the oem stock dcc module. so the stock dcc module communicates on the vehicle CAN, but the apr/dsc module does not. do i have that right?

 

[Cuzoe]

i knew that the apr/dsc module replaced the oem stock dcc module. so the stock dcc module communicates on the vehicle CAN, but the apr/dsc module does not. do i have that right?

Sort of... The stock DCC module receives inputs (via the CAN bus) from various systems on the car (pedal position, accelerometers, braking, level sensors, etc.).
The DCC module also has several outputs... of course it has direct output to the dampers. But it also sends information out to the other systems on the car (via the CAN bus), presumable some info is always sent but it could also send out information by request.

The APR/DSC module is not sending out this additional information, so other systems on the car aren't always happy. This can cause any number of random issues, some noticeable and some not. One noticeable issue seems to be that you lose one of the driving modes. Folks are only seeing the APR/DSC module switching between Normal and Sport, even though the car is requesting Comfort, Normal or Sport.

So... yes the APR/DSC module is on the CAN bus, but no it is not communicating in the same way the factory DCC module would (which would be ideal).

 

[erim86]

ok got it. thanks for your time and patience.

 

[yakboyslim]

Cuzoe got it all. The stock DCC listens and talks, the DSC/APR only listens to CAN.

Some gateway versions notice this, so the gateway basically goes "oh I guess I am not in a DCC car" and stops sending DCC specific requests. Since comfort mode (and suspension setting in individual) do not exist in non-DCC cars, it wont request them. In my case also when I added an aftermarket radio it somehow was requesting something that made the car realize that the DCC wasn't talking, which then caused the ABS module (couldn't turn ESC off) and AFS (headlights pointed as low as they could go) modules to freak out.

Again, the controller does have benefits to it, but for me the CAN bus issues I had were too bad. Some never see these problems, though I have a suspicion that they don't have comfort mode, and just think they do because normal and comfort are close.

Also, to me it is a silly error that zeroing the acceleration tables in the base file makes the car so much better when it was basically DSC's recommendation to do that. Why they don't just update the base file, I don't know.

Lastly, the tech support I got from them was terrible. They initially seemed interested in helping, and putting me in contact with a real engineer, but they clearly do not care about this platform. No matter what problem I was seeing they recommended to "reflash the base file". It never helped, and they never came up with anything past that. They did not acknowledge the problems. The sale of the APR controllers seems to further the complication, with DSC wanting to confusingly deflect to APR at times, despite the two controllers being completely identical (including the base map).

If you get lucky with no CAN issues, and are willing to do some modification of the base maps, not a bad unit - at less than full price.

 

[2019 Golf R]

Definitely check out comfort vs normal - and do you have a OBDeleven/VCDS? It seems at least certain gateway versions do not work in comfort mode (your comfort mode may actually just be normal as well).

Also, if you ever get the urge to deep dive on tuning the controller, I did a fair bit of work on making tools to log and tune with before I sold mine, and would be willing to help answer questions. I would recommend for sure to change the base map by zeroing out the entire acceleration table except for the launch portion (zero the parts based on pedal position). DSC even recommends not to use this table now that they have introduced the launch control tables. It appears they removed the function that would fade the influence of this, so now rather than being a preemptive factor, it just makes the car too stiff whenever the pedal is pressed. Trust me, setting all of that to zero will make the car even better.

I do have OBDeleven and VCDS to test this. I've read about the gateway module of 3q0 vs. 5q0 and with a 2019 R, i'm under the belief i have the 5q0 that has the issues with comfort mode.

Will confirm and post about which one I have then we'll know if comfort mode is now normal mode on my car.

I need to download the DSC software (have to buy a PC to run it)....then i'll be able to test your suggestion on zeroing out the acceleration table.

I had the DSC Controller on my old 6th gen Camaro and found that out of the box, it was lacking significantly on the velocity tables but with APR's involvement i had more confidence in the base map for this car. It's proven to be pretty good out of the box and gave me what i was looking for, and the retail price from APR doesn't bother me for the potential and out of box improvement.

Any other base map changes you'd recommend for the factory dampers and springs? I'm always open to test things out and having the ability to tune is one of the reasons I went this route vs. aftermarket shocks.

 

[yakboyslim]

Besides the acceleration table it's mostly personal preference. I had some changes to the velocity table, but I think MK7 and MK7.5 shocks are slightly different, and the changes from the base map were small.

I wrote some software to take the logs and convert them to csv, which makes them much easier to work with. Also makes histograms, which I used to fine tune the velocity table. I also made a tune creator that works in percentage of overall shock stiffness (makes things easier to tune, and keeps your velocity table consistent, even if you change the shock calibration table)

Both are at github.com/yakboyslim and if you want to use them and have any questions feel free to message me.

 

[2019 Golf R]

Besides the acceleration table it's mostly personal preference. I had some changes to the velocity table, but I think MK7 and MK7.5 shocks are slightly different, and the changes from the base map were small.

I wrote some software to take the logs and convert them to csv, which makes them much easier to work with. Also makes histograms, which I used to fine tune the velocity table. I also made a tune creator that works in percentage of overall shock stiffness (makes things easier to tune, and keeps your velocity table consistent, even if you change the shock calibration table)

Both are at github.com/yakboyslim and if you want to use them and have any questions feel free to message me.

Bad news - went to DSC Sport's website to download the software and they have this:

Important Notice​

Private label suspension controllers are not able to be tuned
with the DSC Sport Tuning Software​

 

[yakboyslim]

I'd download it and try anyway... Unless they changed something in firmware I doubt that. At least as of a few months ago the sticker was the only difference.

 

[Cuzoe]

Bad news - went to DSC Sport's website to download the software and they have this:

Important Notice​

Private label suspension controllers are not able to be tuned​

with the DSC Sport Tuning Software​

Are they referring only to APR (on our platform)? Doesn't APR have their own software anyway? Seems I remember reading they intended to make their software a little more accessible.

Also, as I understand it, APR and DSC worked together on this. The petty side of my mind senses a falling out... could it be related to the CAN bus issues?