Koni GTS Coilover Discussion

[Nineeightyone]

@DerHase I want a video where you roast all the dumb suspension misinformation, I feel like it'd be enjoyable (and I'd likely learn some new things).

also theory here, but shock adjustment should be directly based on springrate, right? Like, you don't want to run a soft spring and then just crank the adjusters so the shock barely moves to achieve 'stiff', because the shock's whole job is to control the spring? And a side thing because I've found conflicting info, Koni yellows/sports are only rebound adjustable, right? Or does the adjustment do damping + rebound?

 

[xXDavidCXx]

@DerHase I want a video where you roast all the dumb suspension misinformation, I feel like it'd be enjoyable (and I'd likely learn some new things).

also theory here, but shock adjustment should be directly based on springrate, right? Like, you don't want to run a soft spring and then just crank the adjusters so the shock barely moves to achieve 'stiff', because the shock's whole job is to control the spring? And a side thing because I've found conflicting info, Koni yellows/sports are only rebound adjustable, right? Or does the adjustment do damping + rebound?

There are two types of movement, bump or also called compression, and rebound. These shocks are only rebound adjustable. If you want bump and rebound adjustment from Koni you must pay more.

 

[DerHase]

@DerHase I want a video where you roast all the dumb suspension misinformation, I feel like it'd be enjoyable (and I'd likely learn some new things).

also theory here, but shock adjustment should be directly based on springrate, right? Like, you don't want to run a soft spring and then just crank the adjusters so the shock barely moves to achieve 'stiff', because the shock's whole job is to control the spring? And a side thing because I've found conflicting info, Koni yellows/sports are only rebound adjustable, right? Or does the adjustment do damping + rebound?

Not sure if I’m ready to open that can of worms yet.

They’re rebound only(ish… there will likely be a small amount of cross talk).

Yes it’s the shocks job to control the spring. There will be one “right” setting up front with minimal benefit going higher or lower.

The rear you generally adjust for balance purposes on turn-in.

You adjust shock rebound to change transition characteristics, not overall grip mid corner in steady state.

Most people set them way too stiff because it “turns in better” but the thing skips around on minor imperfections, ultimately throwing away mid-corner grip.

Compression generally adds grip over bumpy surfaces… up until it doesn’t.

Good (single adjustable) shocks affect compression or rebound only with minimal cross-talk. Preferably rebound because compression generally is more more necessary with changes in unsprung weight or spring rate.


$$$ is needed for GOOD double adjustables.


All the above assumes good shocks. On Chinesium shit they’ll ride like a bag of dicks no matter what. The knobs just adjust how firm the dicks are in the bag.


Out of the hundreds of student cars I’ve hopped in, or cars I’ve codriven… I don’t recall ever needing to stiffen anybody’s shocks when helping develop the car. 99/100 times people run them too stiff which does hurt overall grip, or makes the car lose traction less predictably.

 

[ucfquattroguy]

DerHase: You hit the nail right on the head. Everybody running too much damping is all about perception. We're told that stiffer is more sporty, responsive, etc. In reality, grip is from allowing the suspension to move with weight transfer and imperfections in the road surface (to a point).

More often than not, knobs just get people in trouble. If you're serious, you'll get your shocks in some ballpark of 60-70% critically dampened then just leave it alone. From there adjust as-needed (if the knobs do what they're supposed to...which is why you don't buy shit shocks).

My former B5 A4 Quattro autocross tool ran 800/1000 springs with AST 4150s. Actual wheel rates were 360/340 with how the motion ratios were. Because the ASTs were dialed to the springs to that 60-70% number, it was actually a more comfy ride than my 2013 VW CC daily. Factory shocks on that were over dampened and made the ride fairly "choppy".

 

[Nineeightyone]

Not sure if I’m ready to open that can of worms yet.

They’re rebound only(ish… there will likely be a small amount of cross talk).

Yes it’s the shocks job to control the spring. There will be one “right” setting up front with minimal benefit going higher or lower.

The rear you generally adjust for balance purposes on turn-in.

You adjust shock rebound to change transition characteristics, not overall grip mid corner in steady state.

Most people set them way too stiff because it “turns in better” but the thing skips around on minor imperfections, ultimately throwing away mid-corner grip.

Compression generally adds grip over bumpy surfaces… up until it doesn’t.

Good (single adjustable) shocks affect compression or rebound only with minimal cross-talk. Preferably rebound because compression generally is more more necessary with changes in unsprung weight or spring rate.


$$$ is needed for GOOD double adjustables.


All the above assumes good shocks. On Chinesium shit they’ll ride like a bag of dicks no matter what. The knobs just adjust how firm the dicks are in the bag.


Out of the hundreds of student cars I’ve hopped in, or cars I’ve codriven… I don’t recall ever needing to stiffen anybody’s shocks when helping develop the car. 99/100 times people run them too stiff which does hurt overall grip, or makes the car lose traction less predictably.

Hmmm, good to know -- I'm on yellows on the AX car, with a fairly soft spring (barely stiffer than stock) and have the shocks at about half stiff -- I'll have to see about softening them up.

 

[00Zero]

For reference Koni yellows on soft are about 53% / 78% critically damped on a stock GTI. 175f/230r

The adjusters have the ability to double the total rebound force and could theoretically damper 550f / 1500r springs to 60% of critical, but with no additional compression damping.

@Ninety-eightyone
from a numbers standpoint I would run the rears at full soft and stick with about half stiff maybe a bit less on the front. With a guess of your rates 210f/290r that would get you close to 65-70% of critical, I'm taking an educated but wild as guess at un-sprung weights with driver of 912lbs-f and 550lbs-rear.

 

[Nineeightyone]

For reference Koni yellows on soft are about 53% / 78% critically damped on a stock GTI. 175f/230r

The adjusters have the ability to double the total rebound force and could theoretically damper 550f / 1500r springs to 60% of critical, but with no additional compression damping.

@Ninety-eightyone
from a numbers standpoint I would run the rears at full soft and stick with about half stiff maybe a bit less on the front. With a guess of your rates 210f/290r that would get you close to 65-70% of critical, I'm taking an educated but wild as guess at un-sprung weights with driver of 912lbs-f and 550lbs-rear.

MUCH appreciated! There is a ton I don't know/understand about suspension tuning, that would explain a bunch though as I've got them at half stiff and it's likely what's causing the car to come around all the time. I'll back them off significantly and see, thanks!

Still waiting for the @DerHase suspension video :x