What Spring Rates Are Ok For AGX?

[rico05]

Tried looking all over the KYB website, but I had no luck in finding out what spring rates are within the dampening limits of AGX. I want to use RS-R Race Springs, which have rates of 5kg front, 4.5 kg rear. I don't care if I need to leave the AGXs on higher settings full time, I jsut don't want to destroy the shocks with too stiff springs.

[BadMojo]

Tried looking all over the KYB website, but I had no luck in finding out what spring rates are within the dampening limits of AGX. I want to use RS-R Race Springs, which have rates of 5kg front, 4.5 kg rear.

Search around a bit. We had a discussion about this a few weeks ago. Those are *very* stiff lowering springs. I think they would significantly shorten the life of the AGX's, but that's only conjecture. I know the KYB warranty only allows for a drop of X inches, I don't know if they specify a spring rate that would void the warranty.

You could always call KYB up, tell them the spring rate and application, then see what they say. For what it's worth, when I was considering those springs, Koni told me their Sport shocks could handle 'em, no problem. They even told me this in writing (email)!

There are a few guys around here and FA running those springs with AGXs. It would be interesting to get an update on how the shocks are holding up.

[D1SR240]

how much are those springs?

[Q45tech]

If oem shocks are " X" stiffness, non adjustable aftermarket shocks would be maybe "X + 15-20%".

Even adjustable shocks would at most be 50% stiffer in the extreme.

Custom coil overs need custom shocks. 5.0 / 4.5 kg/mm shocks are 280/250 lb/in roughly twice as stiff as oem fronts/rears.

The reason the Tokico blues work is they are 20% stiffer than OEM and so are most aftermarket springs on average [Eibachs, etc].http://gti-vr6.net/library/sus...k.htmh ... /graph.htm

The problem is you will be halving the spring travel and thus the shock travel.http://www.mail-archive.com/cr....html

[rico05]

I really don't want to seem like a moron, but I am an English major, not a Mechanical Engineering major (although my roommate is) so most of that info is lost on me. Any way I could get a "yes" or "no" on the RS-R springs w/ AGX shoxks as well as a more layman explination? Also, they are only a 1.4" drop in front, 1.2" in the rear.

D1SR240, here is the link to where I would buy these:http://www.store.yahoo.com/pha...Also, watch eBay. They show up on there sometimes.

[Grant@tirerack]

Let me get a swing at this... ( I took physics for poets at Indiana University ) The drop refers to the suspension height (how the car sits on the springs) at rest, not when moving. The drop doesn't tell you all that much about the spring rate etc... just how the car sits with the springs installed. Spring rate refers to how much force it takes to compress the spring and how far it will move under a given amount of pressure. When you put on lowering springs, it will limit how far the piston moves up and down inside the damper (strut). This give the valves less reaction time to slow down the springs as they compress under load and if the valving is not firm enough, the strut piston will bottom out and hit the bottom of the damper housing before it builds up enough resistance to slow or stop the spring from compressing. It's sort of like hitting a sponge with a hammer, if the sponge is not dense enough the hammer will slam into the table top. If you use a denser sponge, the hammer is slowed down faster and will not impact the table top as hard. What you need to do is check with the spring company to get the spring rate specs and then contact the damper company to see if they will work well for that application.

[rico05]

Well, like I said in my last post, I have the spring rates. I tried getting the info from KYB, but their website is all retail and very little numerical information. If the ride height is the issue, how do guys w/ Sportlines or the like with a higher drop not have problems? The RS-R springs are basically the same drop as Tein S-Tech springs, and those have come HIGHLY reccomended around paired w/ AGX. So basically I need to email KYB to see if this will work?

[Grant@tirerack]

I'm sure if you email them direct they can tell you what valve setting you would need to run. As for the drop rate, that can be the same for springs with different spring rates. You could have a firmer spring that will make the car sit 1" lower sitting there. You could also have a softer spring that starts out longer (unloaded) that, when on the car still has the car sitting 1" lower than stock. That's why I say drop rate doesn't tell you a whole lot.

[rico05]

Ok, I just understood from your and Q45tech that drop amount mattered (as you both mentioned it). I didn't think that would have that much of an effect. I guess I asked for more information than I needed as when I said that I was a moron, it was because I understand what dampening and spring rates are. My big issue is with all of the info Q45tech gave about dampening rates and how I couldn't figure out how to read those particular numbers in realtion to my question (considering that none of the shoks tested were AGX) I will contact KYB. Thanks.

[rico05]

Emailed them. I will post what response I get.

[D1SR240]

thanks for the site