Thread: NX2000 rear suspension overhaul

Got rid of the highly overrated CSK Konis in the rear. After just 8k miles the Konis (purchased from Steve Foltz himself) lost all their dampening and clunked like a box of wrenches in the trunk. Very disappointing. I never did understand the unchallenged assumption this is the best B13 suspension option.

Rather than wait for the Konis to be rebuilt, I went with KYB AGX in the rear. I kept the Hyperco Gen2 springs and Koni bumpstops.

I also installed a Progress rear sway bar (thanks Vivid Racing). The pics might be helpful, since the instructions are vague. Hardest part was removing the 22mm nut and bolt on the radius rod.

The parallel links are also new.












Overall, handling is pretty good. The B13 suspension isn't perfect. It's loud and there isn't enough suspension travel, but it's very fun, versatile and easy to work on.

Dean

So you are running the CSKs up front and then the Hyperco and AGX springs in the rear with the progress sway only in the rear? can you take a picture of how the car looks in a side view, what size tires are you running on that setup?

Yellow CSK Konis in the front, Hyperco Gen 2 springs all around, and 195/55/14 tires. Stock front sway bar.

Were the rear konis reds or yellows?

Does it seem to oversteer at limit too much with just the rear sway bar or does it still push in the turns? I had a stock B13 and it would oversteer pretty mean with stock sways, I could not imagine with a stiffer bar just in the rear.

Rear Konis were red, and are apparently no longer available. Steve Foltz, the Koni suspension guru, never gave the specifics.

As far as oversteer is concerned...I don't know. There's definitely reduced understeer, but I haven't tested it at the limit. I never had any oversteer issues with the stock sway bars, but that may be because I am a very slow driver with little track day experience

It is "damping" not "dampening."

Just because one (1) person has a set of Koni's die at 8K miles does not mean that Koni's are not one of thee best options for our vehicles. Every single manufacturer on planet earth sometimes has a glitch or anomaly.

You are one of the first people I have ever seen have a premature failure with Konis on our vehicles. I've been on these forums since 2004, and I don't miss many threads about suspensions. Further, suspension companies and race-shops have been stuffing Koni inserts into our strut housings since at least as far back as Motivational Engineering, must have been around the late 90's when Moti was written up in SCC.

If you (or Steve) somehow came up with Koni Reds, perhaps they were improperly stored on a warehouse shelf somewhere, and the seals dried out? That is merely one (1) possible explanation. If I had more expertise, I am sure I could come up with other possible explanations for a premature failure.


So being impatient, you spent at least as much as it would have cost to have the Koni's rebuilt, to buy an inferior strut set-up to replace them. One of the best things about the Koni's is that they actually can be rebuilt. When your AGX's die, they go in a dumpster. Nor do AGX's have nearly the same quality damping characteristics of the Koni's.


If your suspension is loud for some reason, then you sir are in fact doing something wrong. My CSK (Yellow Spec V fronts, B13 Red rear) suspension is bone-stock quiet. Makes no noise whatsoever.

Hyperco Gen II's, Koni bumps, OEM boots, yada-yada..... Same as yours, no noise. Not so much as a single clunk or rattle.


You are a very slow driver with admitted little track day experience, and yet you want to automatically call-out Steve and question the Koni's, while brilliantly switching to a clearly inferior product? Further, you have the temerity to call into question the Koni's as "highly overrated" based on your very limited and singular experience? Coming from a guy that cannot even build his own CSK's? You want to "challenge assumptions"?!? Simply amazing.

Gee whiz, maybe I should re-write the entire Suspension Thread based on your incredible level of expertise?

You should sell the CSK rears in the Classifieds. Someone smart will buy them and send them to an authorized Koni repair center to be fixed.

Shawn B

I agree, those reds are new OLD stock or used and should have just been rebuilt or replaced with something else. There is no way you can tell me that an AGX rear is better than a Koni.

Brent

Shawn,

Sorry, but I'm not engaging in a manically emotional argument about Konis with you. Look at this post as a one person's experience with one set of Konis. It's an honest account, and it might be useful information for others looking into the upgrade.

Dean,

Sorry, but there is no argument nor debate in which to engage.

I am looking at this as one non-expert persons uneducated opinions, jumping to silly conclusions and attempting to raise ridiculous and highly speculative questions, with their entire experience limited to one set of Konis. Glad we're on the same page.

I am sure it is an honest account, that was never in question.

It might indeed be useful to demonstrate to folks that even the best quality product, with excellent QC from the factory, can have an entirely abnormal and premature failure. Which does not in any way warrant a re-think of the facts surrounding the nature and performance of CSK's or Koni products.

Shawn B