Neo

Well, after considerable discussion here and a general lack of consensus among our membership about how much of a spring rate Koni yellows will handle, I decided to get off my lazy ****, went to the Koni of North America website, and posed the question to them. Below is the answer I received. I was impressed that it only took them a little over an hour to reply to my question. For future reference (in case you're interested more followup), the gentleman who replied is Gordon Benson and his email addy is: gbenson@koni-na.com.
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Casey,

The standard Sport shocks can typically handle up to about a 400 lb/in spring rate before you start running out of adjustment (though I've heard of people using as high as 600 lb/in with the Sport shocks for a while). At that range though, you may want to consider revalving the shocks so that you can have some adjustment range to work with. If you have any other questions, please let me know. Thanks.

Gordon
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So, whaddaya think? I was surprised to see that 400 #s is the high end of what they recommend. Until this, I'd been under the impression that they could handle up to 600 #s, as he even mentioned he's heard. Sounds like revalving is a good way to go if you're going above 400 #s for additional adjustment range. But at $125/shock to revalve, that's not trivial. But what the heck, it's only moolah and we all know, whatever our racing budget is, we always seem to find a way to exceed it.

SJR

I had posted this a while back (Sept 2001). It is coming from Jeff at ProParts, I had asked the exact same question...

[edit]: notice he said 300-350#, I have had my Konis with 380 F, 350R for about 3 years now, and they are pretty far from being adjusted all the way stiff, esp. in the rear. So, I think that 400# is probably about right. At that rate, in order to have a critically damped response from the shock you are adjusted almost all the way stiff. Makes sense to me.


[Modified by SJR, 8:41 AM 5/21/2002]

John

Who here has actually done a Koni revalve? How much of a difference was noted in the shocks performance with a higher spring rate? At $500-550, I'd really like to hear from some first hand experiences...

mantic6t9

i wonder if i'm damaging my yellows with the spring rates i'm running? I guess it could shorten thier lives. So you're saying $560 to have all 4 shocks revalved that sucks when i just payed $550 for them new. If i knew what i know now i would have bought some old *** used ones for really cheap and sent them off to be revalved. For some reason i feel like i've wasted my money, anyone know if they hold their lifetime warrante after the revalving? One more thing will driving around with the set to full stiff shorten their life?

Travis

John

I wouldn't say you wasted your money, but I don't think that there really is a shock out there valved to handle spring rates of 500+ that'll cost you less than a $1000 for a set.

Catch 22

They can handle up to 600lbs, but they'll wear out faster. I know quite a few folks that are doing this.

I had mine shortened and revalved over the winter. I'm still sorting spring rates and sway bars, so I can't yet really say if the revalve is worth the cost because I haven't sorted the suspension as a whole.
I will say that these shocks have ALOT of rebound adjustment in them. At full soft they pop right back out and at full stiff they will not rebound freely (ie: a spring has to uncompress them).

Mike D

so how long should i expect the yellows to last with springs rates of ~ 350/450?


Mike D

RacerMike

I had my shocks revalved and while I haven't run an event on them yet with R tires, on the street the difference is definitely noticable. I suspect that once the R tires go on I will be extrememly satisfied. Supposed to run Rs at the Petersburg Pro but if DSP doesn't make a class I'll probably jump to STX rather than get bumped to CSP. In that case I'll have to wait until Rome the following weekend to know for sure. If I remember I'll post my thoughts here.

Mike

SJR

mantic69,
FYI: keep in mind that full stiff does not mean the **** set all the way stiff up to the stops. Koni writes in their doc that the full stiff setting is all the way to the stops, and then back off a little. You WILL damage your shocks if you run them adjusted all the way to the stops on the stiff side. I believe it was Morgan on this board who had that unfortunate experience...

Hracer

Good point about the full stiff setting.

Also there is still a benefit of running revalved Konis on 400+ lbs springs, even if the regular yellows can also handle those springs. The revalved Konis will do a much better job at it and it will give you better control. The same goes between the "normal" revaled Koni yellows single adj. and the 3011s race double adj. Konis. Both shocks can very well handle the same race springs, but the 3011s (and especially the 2811-2812 series as I've heard) can handle the springs that much better. I've seen the difference between revaled single adjustable yellows and 3011s on the same car with the same spring rates and it is definitely noticeable and better. I would suspect the same goes between normal yellows and revalved normal yellows - they both can handle lets say 500 lbs springs, but one set does it better than the other. I have 500 lbs springs on my Talon with normal yellows and they seem to do a very good job, but I'm sure if I get them revalved the car will feel better.

owen_the_soyboy

WOW good to know...
*goes outside and backs off of full stiff a bit.
pheeeeeeew!

mantic6t9

This is the way i'm looking at it. If they can't handle my springs they will blow and when that happens i'll get them revalved but no sooner.

DB2-R81

Assuming you have single adjustables your goal is to set the rebound to control the energy stored in the springs. If the car feels to floppy, floatly or unstable, you are not controlling the springs and you should increase the rebound dampening.

Now just because they can't control the springs does not mean they are going to "blow". Just means you are not controlling the springs with the amount of dampening provided by the valving of the damper. And your achieved performance will be less than optimal no mater how you set the damper.


[Modified by DB1-R81, 7:36 PM 5/21/2002]

SPiFF

Where in the docs does it day this? I don't remember seeing anything like that with what came with my Konis. I have heard people say that have ran them full stiff without any trouble and some people say they blew very fast.

Hey Casey, wanna ask you Koni guy about this? I have my rears on full stiff at the moment.

manveer

It says it in the directions somewhere...I remember reading it while installing them. Maybe it's on that little sheet that tells you about what settings you should use for what applications (1/2 turn is "cross country" or whatever), but I'm not sure.

John

I think this is what happened to me... I've actually lost my adjustability, likely due to the adjustment pin being bent or something to that extent. If I have them revalved, would this be fixed?

Renegade

I wish I would have know this before I ordered the GC Koni combo, I will be running 350F/400R, I would have liked to save and get the GC dual adjustables.
where do you think I would need the adjustability the most in the front or the rear?

I am thinking to get a set for only the front or the rear for now.

Neo

Ok, I asked the guy at Koni-NA the question about if it's safe to run Koni yellows on full stiff, or to back them off a tad. Here's the answer I got.
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"You can run them at full stiff, but you are better off backing them off some to avoid having the adjuster mechanism jam."
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Hmmmmm, sounds to me like they're hedging a bit, or that they're aren't quite sure themselves. Given that I've never run mine at full stiff, nor do I know anyone who's had problems running them at full stiff, I don't know if this is a real issue or not. Me, I'll follow their advice when I up my spring rates and need more damping. HTH.

John

I called Truechoice today, and they said that if the adjustment mechanism is damaged, it's not an expensive part to replace. A rebuild is $95, plus $10 for the revalve, plus any other small parts that may be needed. Only downside, it's a 3 week turnaround. That's a long time to be without a daily driver...

Guess I'll have to wait until August when my Z arrives...

B18C5-EH2

Well damn. The 2 Koni delaers I've talked to here in Georgia told me that my spring rates would be fine with my Koni Yellows that I ordered:

425F

550R



I currently have a blown set of yellws in my car right now, so I guess the plan is to put in the new Konis and custom Eibachs, then get the money to have my blown ones shortened, re-valved, and rebuilt.

The downtime was 6 weeks from Koni to have my current ones done, so that's why I bought brand new OTS ones.

So what do you guys think I can expect out of the OTS Yellows with 425F and 550R rates?

SPiFF

I am running 400/550 currently with OTS Yellows.

frogsr

i also just went outside and readjusted my front shocks which were on the stiffest setting. good informative post.

96 SOHC VTEC

I have Ground Control coilovers with Koni Yellows, but I am unaware of what my spring rates are. Do the coilovers have the spring rates on them?

Muckman

iTrader: (2)

I am worried about the setup I Just ordered. Ground controls with 500f/400r spring rates with Koni Yellows (8041 series).

What I dont understand is how a stiffer spring will affect the life/performance of a shock.

What I dont understand is how a higher spring rate would be
detremental to the life/performance of a shock. I know when lowering springs
are used in combination with stock OEM shocks, the shock is always
compressed more than what it was designed to work at. And the shock has a
shorter motion range to rebound.

But with the Koni Yellow argument - if I had two sets of ground controls - one with 300lb rated springs and one with 600lb rated springs, the ride height is going to be the same with both sets of springs.

The shock will just rebound less with the stiffer spring, and I dont see how that would be detremental to the life of the shock. It seems like the shock would get less use and abuse. I can see how this would affect ride quality but not shock life.

Steve91

Was this information from Koni specific to a certain car? They cant all be only good for up to 400#. On my Camaro, the factory springs were about 500# in the front STOCK. Koni made shocks for this car and I cant imagine they came with the same valving as those for a civic, for example.