KW DDC Plug & Play with camber plates and suspension lift by gepfeffert

[M4 F83]

After waiting now for almost 2,5 years for this top secret Bilstein Damptronic I decided 1,5 years ago to give the KW HAS a shot. It was a waste of money, the stance was ok but during the 53.000 km the ride comfort was gone – bouncy as hell, maybe they destroyed my OEM EDC dampers. The second point is, if you lower your F8x for about 30mm in the front you have always to be very carefully to not scratch your front bumper, that’s for me a no go for a daily driver – but I want the good looking stance.
So I have done a lot of research, phone calls with development of KW and Bilstein for a perfect solution, nice stance – driving comfort – suitable for daily use.
Always the same answer – no way.

Then 5 weeks ago I read an article about gepfeffert, a small german company, they build special suspension solutions using KW components. I give Andy a call, sure that’s possible if you don’t want to go too low, but max -35mm is enough for me, we discussed the possible spring rates, timeline and give him the go.

Here are the results, please excuse the bad pictures but we have to do a 14h work in only one day and it was night when we finished.

Components







Push button for HLS4



Alignment



front axle lift 30mm





rear axle lift 40mm





Result unfortunately at night, but i will update some better Pictures in the next days



More detailed info about used products and settings
Tires: PS4S 265/30-20, 285/30-20
Wheels: BBS FI-R 9,5x20 ET22, 10,5x20 ET35
Anti roll bar: H&R adjustable stiff position
Spacer: 3mm front to clear the distance between tire and HLS cylinder
Spacer: 3mm rear
Spring rates: front 90 N/mm, rear 130 N/mm should be F 515/R 744 lbs/inch
Alignment:
camber front -1,75°, rear 1,90°
total toe in: front 8’, rear 18’

First driving impressions
On my way back home from installation there was almost no traffic so I was able to pull up to 290 km/h on the German A92 and A96, the stability of the rear axle is great, no more float, real a secure feeling. The bounciness of the KW HAS over bumps has gone completely, the damper sucks up the bump very well, there should only be a slightly more rebound. Maybe I can fix this with the new CS EDC software. Up to 220 km/h the EDC comfort setting is good, above 220 km/h I preferred the sport setting. The sport plus setting is only firmer without gaining an advantage. Maybe it’s the right setting for track, but I don’t track my car.
Is it firmer? YES, but its not harsh.
Yesterday was the first dry day after installation so I go for a drive in our beautiful Austrian Alps with a lot of hair pins, bumps and also bad road surfaces.
The front axle feels fine in turn in but there was a little understeer maybe because of the stiff h&r antiroll bar, so I will change the setting of the bar to the softer side to see if its enough, there should be some flexibility to give you the right front axle grip. There is almost no body roll and a much better feeling behind the steering wheel.
The rear axle is great, beautiful damping over the worst bumps, no harshness, and tons of grip even you flat out of the corner in 2nd gear.
All in all a very good improvement depending on my personal suspension requirements.

I will update more driving impressions after changing the front axle anti roll bar.

[Celestion]

How do they feel?

[Lojs]

subscribed.

I have had long discussions with KW Customer services and they told me the Competition camber plates are not compatible with DDC (nor with V1/2/3).

Have you managed to get this setup compliant to street regulations (eingetragen?)
What was the total cost?

[M4 F83]

I will do the TÜV approval within the next 3-4 weeks, only reason for this time delay is, if i want to change something i have to do the TÜV approval again

For costs please ask gepfeffert.com directly

[Frode D]

Looks like a good solution. How much lower can you go?

[LOW4LYF]

How did you choose the spring rates?

I got told go with 7K and 14K on a coilover setup without tracking the car.

[x.shell]

Originally Posted by Lojs

subscribed.

I have had long discussions with KW Customer services and they told me the Competition camber plates are not compatible with DDC (nor with V1/2/3).

Have you managed to get this setup compliant to street regulations (eingetragen?)
What was the total cost?

They aren't compatible due to the progress spring that comes on the V1/2/3/DDC. The only way to make it work is to change the springs to linear coilover springs like the OP did. It's not a difficult change to do, but that's not information KW would freely give out.

OP:
I'd love to know the details on the lift cup. How were the lines routed. Details on the compressor and remote. The air cup can be utilized on pretty much any coilover that uses 60mm ID springs. Also, post a video!

[Lojs]

Does the geometry change significantly when lifted? is the lifting intended for short slow driving like getting over bumps/ramps etc. or can you drive around in a spirited way as well?

Also at -1,75° your front camber is not much higher than stock. I dont really see the rationale of camber plates in this case.

[M4 F83]

Originally Posted by Frode D

Looks like a good solution. How much lower can you go?

At the moment the car is -31mm lowered in front (10mm more is possible) and -25mm on rear axle (max with my actual setting, you can go 10mm lower if you change the helper spring from 10-60-80 to 3-60-80).

[M4 F83]

Originally Posted by Lojs

Does the geometry change significantly when lifted? is the lifting intended for short slow driving like getting over bumps/ramps etc. or can you drive around in a spirited way as well?

Also at -1,75° your front camber is not much higher than stock. I dont really see the rationale of camber plates in this case.

Yes the geometrie will change a lot, especially in the rear. The HLS System is only recommended up to 80 km/h and not for spirited driving.

My convertible is my daily car on road tires, more camber will influence the driving comfort (road rails) and tire wear and i will not track it. So the intention for this Suspension was a semi OEM stance (as it should be stock), best possible driving comfort and for daily use without compromisses.

[M4 F83]

Setup update:
I changed the h&r anti roll bar as it was still to stiff even in softer setting.
I'm now back on the OEM anti roll bar - perfect for me.

There will be one last Change in the Setup.
Within the next two weeks we will Change the front main springs from 90-60-120 to 80-60-140, so we can max out comfort and possible Suspension travel.

[Lojs]

Originally Posted by M4 F83

Yes the geometrie will change a lot, especially in the rear. The HLS System is only recommended up to 80 km/h and not for spirited driving.

My convertible is my daily car on road tires, more camber will influence the driving comfort (road rails) and tire wear and i will not track it. So the intention for this Suspension was a semi OEM stance (as it should be stock), best possible driving comfort and for daily use without compromisses.

I understand that you don't track it. I also would not track a convertible with CCB and FI-R.
My question was not why you don't do more camber it was why did you install camber plates in the first place? What would have been the camber with OEM mounts?

[M4 F83]

Originally Posted by Lojs

I understand that you don't track it. I also would not track a convertible with CCB and FI-R.
My question was not why you don't do more camber it was why did you install camber plates in the first place? What would have been the camber with OEM mounts?

You cannot use this coilover System with OEM mounts

[M3SQRD]

Originally Posted by Lojs

I understand that you don't track it. I also would not track a convertible with CCB and FI-R.
My question was not why you don't do more camber it was why did you install camber plates in the first place? What would have been the camber with OEM mounts?

OEM upper strut mounts won't work with linear springs with a small constant dia (60 mm in this case) vs. the barrel-type variable-dia OEM front springs. Camber plates are needed to run 60 mm constant-dia linear front springs.

OP - incorrect toe settings cause more rapid tire wear than higher negative camber settings. You'll still get good tread wear if you run -2.0 to -2.5 deg of front camber with slight toe-in. I'm running -2.5 deg camber and zero front toe with Michelin PSC2 tires and I'm getting great tread wear. I'd also recommend running less negative camber on the rear - currently you have more negative camber on the rear than the front. It should be the opposite. Try -1.0 to -1.25 deg on the rear.

[M4 F83]

We used the OEM alignment settings for the GTS, and it feels fine for me

[dinonz]

Do you know if they can supply this as a kit for install, or is it something only they can install?

If I were to enquire with them for a price to get something similar to what you have ended up with, what exactly would I be asking for? Their website doesn't seem to be up to date (doesn't have KW DDC Plug and Play as an option) and I'm worried about things being lost in translation as I don't speak German.

[M4 F83]

Today we finished all suspension work.
We changed the front springs to max out comfort to 80-60-140, added SKF AXK 6590 thrust needle bearings to prevent coilover spring binding and improve spring response and cutted the bump stops about 15mm.

Now it’s perfect for me:

Pro:
- Stance as it should be, not slammed but also no SUV look
- Comfort much much better than with KW HAS springs
- You can use all EDC/M stock buttons as before
- If you have to drive on bad roads you can lift the car about 30mm to prevent damages

Cons:
- A little more road noise from the front wheels due to the camber plates
- $$$$$$$$ - but it’s the only coilover system I know with all this pro’s

[saferisk]

love this