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Passed Driver's Ed
- Location
- Great White North
Intro
Suspension performance can be measured with seat-adjuster vibration analysis, dynamic readings, track performance and on.
I do regular and spirited public road driving and have none of the measurement tools, other than my own subjective observations and comments passengers might make. Meaning this is about my personal impressions and how I got the suspension to work in ways that I like. My driving happens mostly in Ontario and the NE states.
My GTI's
My first GTI was a 2015 non-performance pack model without DCC (Digital Chassis Control = adjustable dampers). In 2019 I traded it for a 2019 Canadian Rabbit edition GTI (B-W differential lock, with DCC, no sunroof, no NAV system). On my cars I keep the complete suspension, wheels and tire size stock. Air pressure set cold at 37 psi.
What I did not like about the OEM suspension
I found the suspension of my (non-DCC) 2015 GTI o.k. but not great. Impacts were sometimes transferred harshly to the chassis. The suspension tended to crash on okay-looking road surfaces, occasionally, leaving me and passengers wonder if a wheel just got damaged. (for reference, our Honda Civic would travel across the same roads with just some thumping noises reaching the cabin, and no jolts or crashing noises).
Hoping the DCC feature on my 2019 GTO would improve things greatly I found it was not so. Only slight improvements. When overwhelmed still too harsh, still crashy here and there and still jolting people when transversing cracks with dips or pushed-up pavement bumps. Driving onto a road when there was, say, a 2” drop from the curb to the pavement always made the front end sound and feel overstressed.
Analysis
The DCC is described in the VW literature as a high-speed electronic damper tuning system, incorporating the input of three chassis accelerometers, steering angle, three chassis level sensors, brake pressure and car speed. While the three DCC settings (Comfort, Normal, Sport) certainly made a difference, my overall impression was that the system was not using all the inputs in a manner that really made the DCC suspension work much better than the non-DCC one. The programming did not seem to make much use of all the data the car generates on all the input channels. The DCC suspension still got overwhelmed in situations where other cars just thumped a bit.
I was not ready to replace springs, dampers and possibly sway bars with all the associated costs for parts, installation, any necessary alignments and camera/radar calibration. Then COVID came which really slowed down the amount of driving I could and needed to do.
Solution
In early March of this year I read in the Golf R section of this forum about a product that had just been released for use in Mark 7 and 7.5 Golf R and GTI. A plug-and-play replacement controller for the VW J250 Electronic Damping Control Unit. An intriguing idea. Simple install without shop involvement, simple uninstall.
Provided that this unit would have the advertised processing and output capabilities it appeared to be a sound engineering approach to suspension improvement.
Through discussions with the company (dscsport.com) it seemed to me they knew what they were talking about. Their website provides free software and the data tables loaded into the controller available. With these one can tweak the suspension to one’s liking by editing the data table and loading it into the controller.
They provide documentation and training videos online as well as phone and online support.
Each DCC damper in the GTI has a current-controlled oil-flow adjustment valve that is attached to the damper body. Which is more limiting in the range of oil flow control than, say, dampers with adjustment valves in the main piston which can adjust across a wider range of fluid flow. Or shocks with magnetic fluid which also have a wider range.
The Golfs also only have one rear axle chassis height sensor on the driver side, requiring a system to work without knowing where the rear right wheel is height-wise. Height data is used to calculate e.g. compression speed to add additional damping in high-speed movement situations. Yet DSC said they can make a considerable performance improvement and I decided to find out.
I installed a DSC controller unit in my car in the middle of this March. Zeroed the damper travel using their s/w. And went driving, just as the ground thawed and country roads around here were in their peak season for shifting and heaving. The car now stayed flat when cornering and no longer dived when breaking. Driving over dips and pushed-up cracks was much more pleasant and without trashy/crashing noises. For my personal feeling this was working much better than what VW had managed to do with their controller.
Adjustments
I found the base calibration setting DSC used for all four dampers a bit too hard for my liking. The VW dampers have an operating range of 240 mA (softest) to 2,000 mA (hardest). I dialled the softest setting for my dampers midway between the one DSC had chosen and the lowest possible setting. I reduced some of the compression settings as well. All good. It took a number of hours to study the controller input tables and the use of the s/w.
When installing the DCS controller with a USB cable plugged in it is easy to use a laptop for changing settings, doing live data recordings etc. The DCS controller installs in the same bracket as the VW J250 box. Inside the driver’s side rear quarter panel, right below the access flap in the carpet where one can undo a rear light plastic installation nut. Open the flap, pull out the USB cable and connect.
And now?
I am just using Comfort mode. I see no need to adjust modes no matter what driving I do. This system does a lot more adjusting, and over a wider damper range, than the VW box.
Seems the DSC Sport unit came with the same data table loaded for all three selectable modes. As I have no need for other settings I have left the other two modes alone.
As a side benefit, since the car no longer dives in the front while breaking, the rear discs get more of a workout and clean off the corrosion caused by all the salt and de-icing liquids used around here nicely now.
Related Findings
A VCDS scan found that VCDS cannot communicate with the DSC controller over the CAN bus. VCDS also reported the Steering Wheel Control Module showing a Level 2 communication error with the DSC box. There are no error lights or messages on the dashboard displays and no indications any systems are not working.
And here we are. I have used the controller for over two months now and am very pleased with the DCC suspension now. I’ll repeat, suspension performance is a very personal and subjective field and I am not saying this unit will make the GTI suspension work as desired for everyone. It costs a significant amount of $ but so do suspension hardware changes.
Suspension performance can be measured with seat-adjuster vibration analysis, dynamic readings, track performance and on.
I do regular and spirited public road driving and have none of the measurement tools, other than my own subjective observations and comments passengers might make. Meaning this is about my personal impressions and how I got the suspension to work in ways that I like. My driving happens mostly in Ontario and the NE states.
My GTI's
My first GTI was a 2015 non-performance pack model without DCC (Digital Chassis Control = adjustable dampers). In 2019 I traded it for a 2019 Canadian Rabbit edition GTI (B-W differential lock, with DCC, no sunroof, no NAV system). On my cars I keep the complete suspension, wheels and tire size stock. Air pressure set cold at 37 psi.
What I did not like about the OEM suspension
I found the suspension of my (non-DCC) 2015 GTI o.k. but not great. Impacts were sometimes transferred harshly to the chassis. The suspension tended to crash on okay-looking road surfaces, occasionally, leaving me and passengers wonder if a wheel just got damaged. (for reference, our Honda Civic would travel across the same roads with just some thumping noises reaching the cabin, and no jolts or crashing noises).
Hoping the DCC feature on my 2019 GTO would improve things greatly I found it was not so. Only slight improvements. When overwhelmed still too harsh, still crashy here and there and still jolting people when transversing cracks with dips or pushed-up pavement bumps. Driving onto a road when there was, say, a 2” drop from the curb to the pavement always made the front end sound and feel overstressed.
Analysis
The DCC is described in the VW literature as a high-speed electronic damper tuning system, incorporating the input of three chassis accelerometers, steering angle, three chassis level sensors, brake pressure and car speed. While the three DCC settings (Comfort, Normal, Sport) certainly made a difference, my overall impression was that the system was not using all the inputs in a manner that really made the DCC suspension work much better than the non-DCC one. The programming did not seem to make much use of all the data the car generates on all the input channels. The DCC suspension still got overwhelmed in situations where other cars just thumped a bit.
I was not ready to replace springs, dampers and possibly sway bars with all the associated costs for parts, installation, any necessary alignments and camera/radar calibration. Then COVID came which really slowed down the amount of driving I could and needed to do.
Solution
In early March of this year I read in the Golf R section of this forum about a product that had just been released for use in Mark 7 and 7.5 Golf R and GTI. A plug-and-play replacement controller for the VW J250 Electronic Damping Control Unit. An intriguing idea. Simple install without shop involvement, simple uninstall.
Provided that this unit would have the advertised processing and output capabilities it appeared to be a sound engineering approach to suspension improvement.
Through discussions with the company (dscsport.com) it seemed to me they knew what they were talking about. Their website provides free software and the data tables loaded into the controller available. With these one can tweak the suspension to one’s liking by editing the data table and loading it into the controller.
They provide documentation and training videos online as well as phone and online support.
Each DCC damper in the GTI has a current-controlled oil-flow adjustment valve that is attached to the damper body. Which is more limiting in the range of oil flow control than, say, dampers with adjustment valves in the main piston which can adjust across a wider range of fluid flow. Or shocks with magnetic fluid which also have a wider range.
The Golfs also only have one rear axle chassis height sensor on the driver side, requiring a system to work without knowing where the rear right wheel is height-wise. Height data is used to calculate e.g. compression speed to add additional damping in high-speed movement situations. Yet DSC said they can make a considerable performance improvement and I decided to find out.
I installed a DSC controller unit in my car in the middle of this March. Zeroed the damper travel using their s/w. And went driving, just as the ground thawed and country roads around here were in their peak season for shifting and heaving. The car now stayed flat when cornering and no longer dived when breaking. Driving over dips and pushed-up cracks was much more pleasant and without trashy/crashing noises. For my personal feeling this was working much better than what VW had managed to do with their controller.
Adjustments
I found the base calibration setting DSC used for all four dampers a bit too hard for my liking. The VW dampers have an operating range of 240 mA (softest) to 2,000 mA (hardest). I dialled the softest setting for my dampers midway between the one DSC had chosen and the lowest possible setting. I reduced some of the compression settings as well. All good. It took a number of hours to study the controller input tables and the use of the s/w.
When installing the DCS controller with a USB cable plugged in it is easy to use a laptop for changing settings, doing live data recordings etc. The DCS controller installs in the same bracket as the VW J250 box. Inside the driver’s side rear quarter panel, right below the access flap in the carpet where one can undo a rear light plastic installation nut. Open the flap, pull out the USB cable and connect.
And now?
I am just using Comfort mode. I see no need to adjust modes no matter what driving I do. This system does a lot more adjusting, and over a wider damper range, than the VW box.
Seems the DSC Sport unit came with the same data table loaded for all three selectable modes. As I have no need for other settings I have left the other two modes alone.
As a side benefit, since the car no longer dives in the front while breaking, the rear discs get more of a workout and clean off the corrosion caused by all the salt and de-icing liquids used around here nicely now.
Related Findings
A VCDS scan found that VCDS cannot communicate with the DSC controller over the CAN bus. VCDS also reported the Steering Wheel Control Module showing a Level 2 communication error with the DSC box. There are no error lights or messages on the dashboard displays and no indications any systems are not working.
And here we are. I have used the controller for over two months now and am very pleased with the DCC suspension now. I’ll repeat, suspension performance is a very personal and subjective field and I am not saying this unit will make the GTI suspension work as desired for everyone. It costs a significant amount of $ but so do suspension hardware changes.