KW COILOVERS vs FACTORY FITTED ACC

[Erik@EVL]

Hi Kaanage,

Spring rates are not adjusted in the KW DDC system. Damper rates and profiles are however adjusted. The spring is also a progressive type hence rate is variable and there is no one single figure to quote. The damper profile is not only variable it is also completely automated with the integration of the VW DCC. Even if we gave an "average" spring figure - it really would be 15% of the story and unfortunately is still not usable or comparable.

Do you drive on KW's by chance?

Cheers

Erik

But the point WhiteJames and I keep coming back to is that an adaptive damping system cannot change the spring rate(s) of the system. It can alter damping to adjust the response frequency which will affect comfort and wheel control to a degree but it doesn't alter the basic stiffness which is set by the springs.

So please can you answer our question on what the relative spring rate increase (since I seriously doubt KW would use the same or lower spring rates) is vs standard.

You imply that the damping changes between modes is more pronounced but that cannot provide a 'firmer rate' unless KW have engineered fully active suspension (which would make them the performance bargain of all aftermarket enhancements).

[WhiteJames]

The question may be better served by being rephrased and the answer may not be known until these units are released onto the market.
Will the KW Dynamic Coilover be an active electronic version of the KW V3 in terms of spring type, rate, progressive nature & damping rates?
How about lowering range?
I'd prefer to keep around stock OE ride height for the GTI. Will this be possible with the KW Dynamic Coilover? (It may be too early to ask this question atm).
If the KW Dynamic KW Coilover has a lowering range the same as the KW V3, it would suggest that the spring & damping rates are the same as the KW V3.
This will help with determining the baseline for the KW Dynamic Coilover.
Should the KW Dynamic Coilover be tuned like the KW V3 across it's spectrum of progressive spring rate & damping range, then it may be a bit on the firm side for my preferences.
Given time, it may well be that KW expands the range to include a KW Street Comfort Dynamic range with a softer progressive spring rate and damping range.
Cheers
WJ

[Preen59]

Spring rate only determines some of the "firmness" you feel when you are driving your car. Bump and rebound valving also has a large influence on this. So you cannot quantify that the DCC kit will be "as stiff" as the V3s just on the fact that the spring rates are equal.

When you adjust the bump and rebound settings, you are adjusting how easily the oil in the shock can flow through the bump and rebound (compression and extension) valving. The easier you allow the oil to pass through the valves, the faster it will transfer for a given force and the softer the ride will feel.

Spring rate and bump also is not the only thing that can give you a firm/rough ride. Rebound settings also come into play.

A friend of mine who has V3s in a Mk1 has 2 baseline bump/rebound settings, front and rear for his. One setting for track and one for daily driver duties. The daily driver setting is a couple of clicks softer on both, and there is a noticeable difference.

[kaanage]

Sure but the damping can only modify the response so much until there is a mismatch with the spring rate and then you either get a 'jouncy' ride over larger bumps (underdamped) or a jarring ride over small ones (overdamped, esp compression).

I understand that have different low and high speed compression damping curves helps broaden the acceptable response but the spring rates still set the stiffness from which the damping must work within.

In the ideal world, we would have zero compression damping and active infinitely variable rebound adjustment to prevent oscillation and "packing down" but this doesn't exist (or not at this price point). Actually, active infinitely variable compression adjustment would almost certainly be needed to prevent "packing down" but it could be far lighter than for a static (even if adjustable) response curve.

Do you drive on KW's by chance?

No, I currently run another German brand of aftermarket suspension on one of my cars and have used them and a Dutch brand in the past (and an Austrian and a Swedish brand with race vehicles).
The car with ACC is very unlikely to be altered at this stage since comfort is at least as important handling for this car and any noticable increase in stiffness over the std GTi would not be suitable.

[Corey_R]

I don't claim to be a spring expert, but I do own a Golf R with DCC.
Within the range of adjustment with the stock DCC system, I don't believe there is any issue with the spring rate. Whether you have it in comfort, normal, or sport, the system works great.

What you need to remember is that it is DYNAMIC. It's not just "set to comfort" and the damper/rebound reacts in 1 manner. It dynamically adjusts within milliseconds to the current conditions based on a myriad of measurements which are being taken 1000 times per second.

I think the other point that should be remembered is this:
Someone who has purchased a car with DCC understands that they're are compromised to be had and that it is not the "ultimate" in either comfort OR sport performance. It's close to a "best of both worlds" solution.


If you want a floaty ride, lets face it, you'd have bought an American car If you want performance, you'd already be on some form of aftermarket suspension/swaybars/ALKs. You're using DCC because it allows you to be rather comfortable one minute, and then rather sporty the next. If the KW DCC solution allows you to keep a similar comfort level of the stock DCC system and yet provide a bit more sportiness when required, then I'm all for it.

I'm sure the engineers at KW know what they're doing

[kaanage]

In the ideal world, we would have zero compression damping and active infinitely variable rebound adjustment to prevent oscillation and "packing down" but this doesn't exist (or not at this price point). Actually, active infinitely variable compression adjustment would almost certainly be needed to prevent "packing down" but it could be far lighter than for a static (even if adjustable) response curve.

But then a system as responsive as this would actually make the spring rate even more important in determining the ride since the damping would almost be transparent as far as initial bump response goes (separation of concerns would be the IT buzz phrase for this)

I'm sure the engineers at KW know what they're doing

I'm sure they do - I just want a little technical detail (not enough to disclose trade secrets) on how they achieve this.

[Preen59]

Give it a few days for Erik to reply with a detailed answer as he is currently in Germany at KW checking out the new products first hand.

I don't claim to be a spring expert.................

I'm sure the engineers ......... know what they're doing

2 things I don't read enough on internet forums..

And I mean no discredit to you, Corey.

[gokartgti]

Did we ever get a response to the questions posted by WJ or are they elsewhere on the forum.

[Corey_R]

No, it wasn't answered, here or elsewhere on these forums.

[WhiteJames]

Erik @ EVL Motorsport indicates that a couple of KW DCC coilover kits will be installed on Golf's in the near future with owner's reviews online to follow. Apparently Volkswagen allow for a 20mm drop in terms of sagging over the life of the OE coil springs, although my GTI at 27,000 km appears to have not budged in terms of spring sag. The KW DCC lowers min 15mm at the rear, which means going 20-25mm at the front for a slight wedge look and some improved turn-in response - this is too low for my liking. I'd like to keep around OE ride height to Golf R ride height at it's lowest - ideally 5-10mm drop front and 0-5mm rear drop. Additionally and as stated before, spring & damper rates about the same at the Renault Megane RS250 would be ideal for a comfort/sport trade-off as a daily driver - which is about 15-20% firmer than the Golf GTI imo, but not as firm as the KW V3 (possibly KW DCC if the're anything like the KW V3) which feels to be another 15-20% firmer than the Renault RS250 spring and damper rates and about 35% firmer than the stock OE Golf GTI spring & dampers rates. You're also likely to get a bit of rubbing on the front outside fender screw/screw flange with the lower ride height at the front, which is not what I'm looking for either - bring on the KW DCC Comfort coilover. Another issue is cost - drop 4K on the Golf GTI or put that money into a brand new vehicle with new warranty (Golf MK7, Polo GTI or Megane RS250). Looking forward to the owners reviews of the KW DCC coilover and Roaming_Nick's review of his new Mark 5 GTI OHLINS DFV coilovers.
Cheers.
WJ