Koni Yellow / GC Coilover Review (long)
10-24-2015, 03:48 PM
#21
Update:
So I spent some more time setting the damping. One thing I relized is setting the front stiffer than the rear made the feeling of extra ocilation in the rear more noticeable. Overall the car feels the best with the damping even front to rear. I guess that makes sense since the springs are the same.
Being spring rates, ride height, alignment were all static, I spent some time playing with the damping on the street. I drove for some time at full soft and full stiff to determine what direction to go in. Between the two full soft was far better, ride, handling, grip, everything seemed better at full soft. At full hard the suspension crashed over bumps and the chassis fell into dips in the road. The chassis moved in an over reactive way. At full stiff the reaction of the suspension seemed high frequency as it bounced between the stiff rebound and the springs. As the car drove over the road it almost shivered, reacting to road imperfections.
While full soft felt better than full stiff there was still issues. The movement of the suspension, while lower in frequency, moved more which made the car grip vary. It never felt settled, especially loading up in a corner. The rate of body roll contributed to changes in balance. I noticed in a corner, without extra steering the car would tighten up (oversteer) as the suspension took a set.
Moving to 1/2 turn out seemed to help. All the good of being at full soft, but adding some control and predictability in the corner. I will keep testing but clearly with this setup you need to pick your compromise. The stiff springs help the lack of bump damping, but you have to be careful not to lock down the suspension with two much rebound. I credit the konis for the isolation of rebound control and the full range of damping adjustment. The difference between full soft and stiff is substantial.
It seems the car will feel best on the street somewhere around .5-1 turns out. Any more and the suspension will start to crash. As far as the track, my research indicates that people seem to go faster when the shocks are softer. However the car may feel better on a smoother surface with more control, around 1.25 turns out.
Bottom line it's taken some time but the car feels great. It's almost hard to believe this is a "budget" setup.
So I spent some more time setting the damping. One thing I relized is setting the front stiffer than the rear made the feeling of extra ocilation in the rear more noticeable. Overall the car feels the best with the damping even front to rear. I guess that makes sense since the springs are the same.
Being spring rates, ride height, alignment were all static, I spent some time playing with the damping on the street. I drove for some time at full soft and full stiff to determine what direction to go in. Between the two full soft was far better, ride, handling, grip, everything seemed better at full soft. At full hard the suspension crashed over bumps and the chassis fell into dips in the road. The chassis moved in an over reactive way. At full stiff the reaction of the suspension seemed high frequency as it bounced between the stiff rebound and the springs. As the car drove over the road it almost shivered, reacting to road imperfections.
While full soft felt better than full stiff there was still issues. The movement of the suspension, while lower in frequency, moved more which made the car grip vary. It never felt settled, especially loading up in a corner. The rate of body roll contributed to changes in balance. I noticed in a corner, without extra steering the car would tighten up (oversteer) as the suspension took a set.
Moving to 1/2 turn out seemed to help. All the good of being at full soft, but adding some control and predictability in the corner. I will keep testing but clearly with this setup you need to pick your compromise. The stiff springs help the lack of bump damping, but you have to be careful not to lock down the suspension with two much rebound. I credit the konis for the isolation of rebound control and the full range of damping adjustment. The difference between full soft and stiff is substantial.
It seems the car will feel best on the street somewhere around .5-1 turns out. Any more and the suspension will start to crash. As far as the track, my research indicates that people seem to go faster when the shocks are softer. However the car may feel better on a smoother surface with more control, around 1.25 turns out.
Bottom line it's taken some time but the car feels great. It's almost hard to believe this is a "budget" setup.
10-24-2015, 10:51 PM
#22
Looking back at it...would you go a different route you think? I am a 17x9 square set up. What spring rates would you recommend for me? 700 and 500? My main concern would be for the track.
10-25-2015, 03:57 AM
#23
If you are running square, it sounds like a more dedicated track setup. However, 700lb springs may be too much for the konis. Maybe 600/500. Also the konis are a great street/track shock. Paired with springs around 450-550, they offer great body control, bottoming resistance and ride. However they don't build compression really fast, so if you are looking for that ultra starp response, you may consider a montube. I feel they are plenty responsive, but it depends on how you like your setup.
10-28-2015, 08:50 AM
#24
OK, so I have spent a great deal of time adjusting the damping for the street. I started at the extremes (full soft vs. full hard) and moved in 1/2 turn at a time and did a better/worse comparison. As stated before, evening the damping front to rear has cured most of the oscillation issues. So even at full soft, the ride is not really bouncy.
There are two issues with being at the softer side of the scale. One, the suspension moves faster in a turn which changes the speed of rotation. The car almost feels unpredictable as you wind the wheel and the car takes a set. Two, at high speed over bumps the car seems a little un-settled, not floaty, but close. These bad traits start to disappear as soon as 1/2 out from full soft.
On the stiff end of the adjustment, the suspension was awful. It crashed hard over any bumps/dips, it shivered over seemingly smooth roads and it allowed the chassis to completely "fall" into even shallow pot holes. Adjusting the shocks to at least 1 turn from full hard (which is about the same as one turn from full soft) was enough to correct most of these issues.
I ended up on the compromise of 1 turn out from full soft on all shocks. 3/4-1 seems the sweet spot. The ride is much better than my first review, the control is great, grip is excellent and no bounciness. The suspension and chassis are controlled but not locked down.
There are still issues, the most notable (compared to stock) is the reduction of initial sharpness during steering inputs. It seems the Koni will not build compression damping fast enough to have the same sharpness of the stock shocks. You can get most of the sharpness back by jacking the rebound damping, but then you get a host of other issues. Letting the suspension do its job (reduce rebound damping) seems to be the best solution. Relatively the steering is still sharp, just not as sharp. Plus the Konis seem better at keeping the tires on the road over imperfections. The more time you spend driving the more you realize the Konis are allowing the tires to generate more grip for the chassis. I can see why people have been able to go very fast with these shocks.
Bottom line. This is the cheapest shock I know of that appears to be a net upgrade over the very good oem shocks. The Koni damping profile has issues but it solves more problems than it creates. With the GC springs, this is a budget coilover that will actually improve an S2000.
There are two issues with being at the softer side of the scale. One, the suspension moves faster in a turn which changes the speed of rotation. The car almost feels unpredictable as you wind the wheel and the car takes a set. Two, at high speed over bumps the car seems a little un-settled, not floaty, but close. These bad traits start to disappear as soon as 1/2 out from full soft.
On the stiff end of the adjustment, the suspension was awful. It crashed hard over any bumps/dips, it shivered over seemingly smooth roads and it allowed the chassis to completely "fall" into even shallow pot holes. Adjusting the shocks to at least 1 turn from full hard (which is about the same as one turn from full soft) was enough to correct most of these issues.
I ended up on the compromise of 1 turn out from full soft on all shocks. 3/4-1 seems the sweet spot. The ride is much better than my first review, the control is great, grip is excellent and no bounciness. The suspension and chassis are controlled but not locked down.
There are still issues, the most notable (compared to stock) is the reduction of initial sharpness during steering inputs. It seems the Koni will not build compression damping fast enough to have the same sharpness of the stock shocks. You can get most of the sharpness back by jacking the rebound damping, but then you get a host of other issues. Letting the suspension do its job (reduce rebound damping) seems to be the best solution. Relatively the steering is still sharp, just not as sharp. Plus the Konis seem better at keeping the tires on the road over imperfections. The more time you spend driving the more you realize the Konis are allowing the tires to generate more grip for the chassis. I can see why people have been able to go very fast with these shocks.
Bottom line. This is the cheapest shock I know of that appears to be a net upgrade over the very good oem shocks. The Koni damping profile has issues but it solves more problems than it creates. With the GC springs, this is a budget coilover that will actually improve an S2000.
10-29-2015, 08:20 AM
#26
Don't recall specifically, and not necessarily OTS. Also, I could have been reading threads from 2002 like this one... 
http://www.sccaforums.com/forums/aft/21433
http://www.sccaforums.com/forums/aft/21433
10-21-2016, 09:51 PM
#27
Sorry to bump an old thread, but I want to add here that all the things I've felt are mentioned by Apex.
I got my koni/gc installed this past Wednesday. The coilover has 380/340 spring rate, and I bought them used at unknown condition (lol). My ride height is 2 finger gaps all around (I just want to lower the car a bit. I'm basic I know
). I'm running 255 square RE11As, unknown mileage again (lol). My wheels are +53 offset front and +63 offset rear, so the wheel centerlines relatively remain at the same location as stock setup (+55 and +65).
Two
s and one 
:
1. Less sharp turn in.
This is really disappointing, since I really love the turn in response when I first switched to square re11 on OEM suspension. The car just turned in so sharp. By switching to Koni/GC, the transition is not really crisp in the very beginning. I agree with Apex's theory, since this phenomenon falls in line with the belief that compared to stock, konis are softer in compression and harder in rebound. I'll see if I can play with damping a bit to tune it out. Since my spring rates are significantly lower than Apex's, maybe (just maybe) I can get away with all the harshness associated with cranking up damping.
2. Rear bounciness
Holy crap the rears are definitely underdamped. It could be that the rears are on its way out, but it also can be the damping setting is just not optimal. Fortunately a local s2000 owner generously gave me his adjuster, so I can mess with damping a bit during this weekend. Apex did it by driving on highway, which I find reasonable. I'll start from there and basically redo everything Apex did. Hopefully it'll make a difference.
3. (Seemingly) Better mid speed cornering.
This is a weird thing to explain, but I feel like car is more stable at quasi-steady-state cornering, in some "high speed" corners. Since I was driving in a mountain road, everything above 60 is high speed to me. Maybe it's because of the (barely) lower CG? Maybe it's the harder springs? Or maybe it's just me being high? I don't know, but this is definitely a plus.
Summary on my car: Square re11a, 380/340 gc, unknown shock condition, didn't do alignment, didn't do corner balance. We'll see what's up next.
Have fun with your cars!
I got my koni/gc installed this past Wednesday. The coilover has 380/340 spring rate, and I bought them used at unknown condition (lol). My ride height is 2 finger gaps all around (I just want to lower the car a bit. I'm basic I know
). I'm running 255 square RE11As, unknown mileage again (lol). My wheels are +53 offset front and +63 offset rear, so the wheel centerlines relatively remain at the same location as stock setup (+55 and +65).Two
s and one : 1. Less sharp turn in.
This is really disappointing, since I really love the turn in response when I first switched to square re11 on OEM suspension. The car just turned in so sharp. By switching to Koni/GC, the transition is not really crisp in the very beginning. I agree with Apex's theory, since this phenomenon falls in line with the belief that compared to stock, konis are softer in compression and harder in rebound. I'll see if I can play with damping a bit to tune it out. Since my spring rates are significantly lower than Apex's, maybe (just maybe) I can get away with all the harshness associated with cranking up damping.
2. Rear bounciness
Holy crap the rears are definitely underdamped. It could be that the rears are on its way out, but it also can be the damping setting is just not optimal. Fortunately a local s2000 owner generously gave me his adjuster, so I can mess with damping a bit during this weekend. Apex did it by driving on highway, which I find reasonable. I'll start from there and basically redo everything Apex did. Hopefully it'll make a difference.
3. (Seemingly) Better mid speed cornering.
This is a weird thing to explain, but I feel like car is more stable at quasi-steady-state cornering, in some "high speed" corners. Since I was driving in a mountain road, everything above 60 is high speed to me. Maybe it's because of the (barely) lower CG? Maybe it's the harder springs? Or maybe it's just me being high? I don't know, but this is definitely a plus.
Summary on my car: Square re11a, 380/340 gc, unknown shock condition, didn't do alignment, didn't do corner balance. We'll see what's up next.
Have fun with your cars!
10-25-2016, 02:28 AM
#30
The range of damping adjustment on the konis is significant, so you change both the feel and performance by turning a knob. I use 1/4 turn increments, it's enough to feel but the changes are subtle. At every damping level you will find something to complement and complain about. However the more you drive and change the setting, the more likely you will find the right setting for you.
Make sure you have enough rear piston travel before hitting the bumpstops. You may need to make some modifications as I did.
I would start with 3/4 turn out from full soft on all four shocks. however I do recommend driving the car through the range of adjustments. You learn a lot about how the damping changes effect the car. Even at the worst the konis are a great beginner shock for this reason.
Make sure you have enough rear piston travel before hitting the bumpstops. You may need to make some modifications as I did.
I would start with 3/4 turn out from full soft on all four shocks. however I do recommend driving the car through the range of adjustments. You learn a lot about how the damping changes effect the car. Even at the worst the konis are a great beginner shock for this reason.