Good Afternoon,

I currently own a 2019 C63S AMG Sedan, Vehicle is lowered on H&R Sport, I have been dealing with the vehicle being loose or not as planted on the ground/ skating over 120mph, I have rebalanced all wheels aswell as had a suspension shop tightened all suspension bolts and go over it all, please look at attached alignment as it seems chinese to me and let me know what I can do to fix this issue. Thank you

 

YES EVEN THOUGH A C63 ‘S’ AMG “PERFORMANCE” MODEL - Reality is OEM there is no Front Camber or Caster and no Rear Camber adjustment (new car industry’s best kept secret).

With majority of suspension bushings being soft rubber.

OEM there is now only Front and Rear TOE “directional” adjustment.

ALL TO DO WITH COST CUTTING AND EVER INCREASING SPEED OF NEW CAR ASSEMBLY LINES. STOPPING TO ADJUST / SET CAMBER IS NO LONGER AND OPTION !

Now Camber is factory set to suit showroom height conditions.

WE SAW THE NEED THEREFORE - AND MANUFACTURE A “TOTAL SYSTEM” !

NOT ONLY FRONT AND REAR TO EASILY DIAL IN CAMBER CHANGE FOR PERFORMANCE DRIVING / TRACK DAYS - OR ADJUST TO PREVENT COSTLY PREMATURE EDGE WEAR.

BUT SAME TIME UPRATING THE SUSPENSION BUSHINGS.

EXAMPLE:
K-MAC #503316M $595 (Both Sides) REPLACES AND UPRATES - the 4 major front suspension bushes !

PROVIDING ALSO PRECISE EASILY ACCESSIBLE SINGLE WRENCH ADJUSTMENT OF CAMBER & CASTER.

Plus the forward facing (large diameter) OEM bushes - soft rubber oil filled. K-MAC replacements are not only Caster adjustable but are also MONO BALL / SELF ALIGNING !

Allowing arms to still travel through their required suspension arcs - but significantly improving “Brake and Steering” response.

SAME FOR REAR SUSPENSION
K-MAC #502226K $480 (Both Sides) REPLACES AND UPRATES - the 2 large diameter lower arm soft rubber bushes and provides Camber adjustment (same as front precise easily adjustable single wrench).

To compensate for the addition of rear Camber. This kit includes extra Toe adjustment (doubling the range).

NOTE: K-MAC FRONT CAMBER & CASTER ALONG WITH REAR CAMBER ARE SPECIALLY DESIGNED TO FIT WITHOUT NEED FOR SPECIAL TOOLS OR TIME CONSUMING CONTROL ARM REMOVAL !

WHILE #502628K $480 (Both Sides)
REPLACES AND UPRATES THE ‘6’ REAR MULTI LINK ARM BUSHES.

RESULT – TAUTER RESPONSE, LESS REAR END FLEX, REDUCED WHEEL HOP / GAINING TRACTION. ESPECIALLY WHEN APPLYING POWER TO LANE CHANGE / OVERTAKE.

#502326-3J $380 (Both Sides)
UPRATED REAR TOE ARMS - Prevent flex / Toe change (use in conjunction with rear Camber kit).

TOE ARMS AND THE ABILITY FOR CAMBER ADJUSTMENT - MEAN TRACK DAYS - CAN DIAL IN EXTRA NEG. CAMBER TO REDUCE UNDERSTEER IN THE PURSUIT OF HITTING THOSE CORNER APEXES EVERY TIME AND ALLOWING TO GO DEEPER INTO THE CORNERS WITH INCREASED TRACTION AND BRAKING RESPONSE. FOR FRONT ROW OF THE GRID LAP TIMES.

DHL DELIVERY $40 one kit ($20 each extra)
sales@k-mac.com ….web: www.k-mac.com ….1888 847 9099 (Sales Tech 24/7)


SEE SPOILER






AUDI to VOLVO - Experience Resolving OEM Suspension Shortcomings (and costs) Since 1964 !

 

The simple fact is if you lower the suspension, you mess up the suspension geometry. Similarly if you put wider wheels on it with incorrect offsets or go the cheap route and put on spacers. Specifically, lowering the suspension increases negative camber, so your tires roll on the inner edge even more when driving in a straight line. The right amount of negative camber is great for cornering as during cornering the tire will have full contact patch as the weight shifts to the outside. Lowering the suspension also means compromising suspension travel, and if you only lower it with springs then you compromise the dampers as they will always be partly compressed already and won't have proper compression and rebound range, and the suspension control modules will also incorrectly think the car is loaded with a bunch of passengers and cargo due to it sitting lower, so it will adjust the damping incorrectly. There are sensors in the wheel assembly that measure the ride height at each corner and then that gets factored into the adaptive algorithm which is tuned for the stock setup and not a lowered setup..

Springs, dampers and the electronics have to be tuned together. Lowering cars is mainly done for optics, but actually makes the suspension perform worse, unless you take a more comprehensive approach and retune the entire suspension with properly matched dampers and use adjustable control arms and such to be able to align everything properly. Good quality coilovers is the best way to achieve this, as those are a complete spring and damper setup matched to each other, but in case of adaptive suspensions such as the AMG Ride Control suspension, you lose the adaptive part and the ability to adjust the suspension on the fly via the drive mode. Coilovers are usually adjustable, but you have to get under the car and wrench to manually adjust it.

 

-2.5 degrees camber is very aggressive for the street. All 4 of your tires are leaning inward at the top, leaving less contact patch on the ground when driving straight. Therefore, at high speed you have way less contact patch on the road and it is probably contributing to the loose feel. Your camber spec would be great for lower speed AutoX... Or aggressive full track use. But for a street car it's pretty high.

Your front toe-in seems good, but it looks like your left rear has a little toe-out and your right rear has a little toe in (picture is a little blurry) ... Overall the rear has a good total toe-in, but that left rear toe out might be also contributing to that loose feeling you describe at high speed. A tiny bit of Toe-out (in the front) feels great when turning into a corner on a track but makes the car feel loose at high speed. Toe is adjustable.

The way to fix the camber is with KMac's bushings, so that your camber is adjustable and you can set it to like - 1 to - 1.5 degrees.

 

Has it always felt this way? Did the issue start with the H&R springs? What tires are you running and what size? What was the temperature outside?

I bought my 2018 that had an H&R VTF kit (waaaaay lower than springs alone) and I totally agree with Superswiss and Roysup. The ride characteristics were a mess and had a lot of drama at any speed. But I didn't feel comfortable above 80. I went back to stock and it's a completely different car. There was also an unknown "warning" code that couldn't be cleared with any of the scanners I had. It ended up being an "out of range" warning for the suspension system being too low. It had a big impact on dampening regardless of what mode I was in. Car now launches better, corner betters, and feels more planted at triple digit speeds.

I'd also check your tires. If you're lower, you're going to have more camber, and possibly more wear on the inner portion of the tires. And not sure what kind of tires you have, but my rear end can feel floaty with summer tires\drag radials if I don't have enough heat in them and the temp is colder (40-50).

 

I’ve been to Sebring and did 150 in the back straight if I get the corner exit right. I never felt the car, unsettled or uneasy. I’m at stock suspension with a custom alignment from a race suspension shop. 1/32 upfront and 3/32 toe in the rear. On the gas cap, there are two tire PSI recommendations. 0 to 150 and then a higher speed setting. Be sure to use the one that you’re going to be riding at.