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spring rate for kyb agx ,gc

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Old Jan 25, 2014 | 11:04 PM
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spring rate for kyb agx ,gc

I have kyb agx and gc adj springs, but my front spring is at the lowest setting and not as low as I would like, I have about a 2 finger gap and I would like it a little lower. since I would be getting new springs anyways, I was wondering if anyone that street drives/weekend track would have a good spring rate they recommend.
I have a s4 t2 with st sways, manual rack, ac delete, and I should be pushing high 200, low 300whp. I have yet to decide tire choice yet

recommendations on sway bar settings? thanks
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Old Jan 26, 2014 | 10:30 AM
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I've heard the st bars bind at the stiff setting, so I'd leave them on soft.

What spring rates are you running now and how do you feel about them? Did you want to change all 4 springs or just the fronts?
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Old Jan 26, 2014 | 11:35 AM
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Here is what I have on my two cars:

Street driving/autocross: KYB AGX with Racing Beat springs, no other suspension mods.

Weekend track: Koni Coilovers, Eibach ERS Springs 7" 400lb Front / 10" 275lb Rear, Eibach Anti-Roll Bars, Urethane and Delrin Bushings, Delrin Toe-Steer Eliminators, Mazda Comp Front Camber/Caster Kit, AWR Rear Camber Kit, AWR Rear Center Brace. The front anti-roll bar is currently off the car, otherwise I would have taken a look to see where it was set. However, you can use my method of suspension tuning... ask a good driver to try your car on the track and adjust the suspension accordingly, lol.
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Old Jan 26, 2014 | 01:31 PM
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From: https://www2.mazda.com/en/100th/
its my experience that the shocks have the biggest impact on ride quality. the second bit is that the FC doesn't need super stiff springs to work at the track, so happily you can have a car that works really well on the street AND the track.

we have 4 FC's running around;

1. is a GTUs, its running 400/300 springs with konis, the handling is awesome, huge fun, it also rides the best.

2. is a 1987 GXL. 320/220 springs with AGX's. it rides a little harder than the GTUs, handling is really good the suspension is literally from our old ITS car, which had a number of wins...

3. 1989 vert; GAB shocks (they look a LOT like AGX's), 200/200 springs. surprisingly nice combo on the street, it feels like a BMW, softly sprung and a little over damped. i would have thought such soft front springs would be obviously bad, but its not at all. haven't tracked it.

4. same vert, stock suspension. ride is about like the GXL, its the most tail happy of the bunch...

conclusions? the FC works well with a spring rate between 300-400 in the front and 200-300 in the rear (250 is a happy spot), and with decent shocks, can actually ride very nicely at the same time.

the AGX's usually end up around 1-2 in the front and 2-3 in the rear, on the street. they are there to damp the spring, and not to change the ride
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Old Jan 28, 2014 | 10:42 AM
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Thanks for the info guys!

Originally Posted by Evil Aviator
However, you can use my method of suspension tuning... ask a good driver to try your car on the track and adjust the suspension accordingly, lol.
LOL

Originally Posted by eage8
I've heard the st bars bind at the stiff setting, so I'd leave them on soft.

What spring rates are you running now and how do you feel about them? Did you want to change all 4 springs or just the fronts?
I will have to look at the part number on the springs again. I bought my car used with the gc adj springs already installed. I'm guessing it has the spring rates that come out of the box.
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Old Jan 28, 2014 | 10:57 AM
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You laugh. You will never get better feedback than an experienced pro driver jumping in your car for 5 laps...
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Old Jan 28, 2014 | 07:29 PM
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Originally Posted by RockLobster
You laugh. You will never get better feedback than an experienced pro driver jumping in your car for 5 laps...
^ 100% truth! I do think it's funny though because the solution is soooo simple.
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Old Jan 28, 2014 | 10:20 PM
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Originally Posted by RockLobster
You laugh. You will never get better feedback than an experienced pro driver jumping in your car for 5 laps...
I know, I'm sure a more experienced driver would know how to setup my car better. I just thought it was funny the way he said it.

I remember when we were setting up our time attack car from Tarzan Yamada to drive and he had a lot of feedback. Of course we had a translater. Only if he could drive my car, but he probably wont want to
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Old Feb 1, 2014 | 01:03 AM
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Originally Posted by j9fd3s

the AGX's usually end up around 1-2 in the front and 2-3 in the rear, on the street. they are there to damp the spring, and not to change the ride
Thank you, that was very helpful. What settings do you usually use if you were to track a car with agx?
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Old Feb 1, 2014 | 11:18 AM
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From: https://www2.mazda.com/en/100th/
Originally Posted by GrossPolluter
Thank you, that was very helpful. What settings do you usually use if you were to track a car with agx?
in a perfect world it would be the same, or very close

there are two valves inside a shock, a low shock piston speed valve and a high shock piston speed valve. for the most part, the high speed valve = ride quality, and the low speed valve = handling.

so it is possible to have shock valving that handles AND rides optimally, 90% of the time*

the problem with the AGX, is that the two valves aren't adjusted independently, so we need to choose weather the high speed or low speed is right, and given the choice we choose handling. we can change spring rates, and change the weight of the car a little, to make the shock work more optimally**

so short story long***, you'll have to play with it, try full soft, and full hard, and then maybe half way, and see what you like. laptimes won't change much, so you pick the easiest to drive/most consistent setting.

*generally you're going faster at the track than the street...
**we usually run a 300/250 spring with the AGX's, and 400/300 with the koni's.
*** i've been reading a lot of books with footnotes, can you tell?
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Old Feb 28, 2014 | 11:46 AM
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Originally Posted by j9fd3s
2. is a 1987 GXL. 320/220 springs with AGX's. it rides a little harder than the GTUs, handling is really good the suspension is literally from our old ITS car, which had a number of wins...
What springs were you using on this setup? Ground Control style with adjustable sleeves?
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Old Feb 28, 2014 | 12:42 PM
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From: https://www2.mazda.com/en/100th/
Originally Posted by Laxfreak3557
What springs were you using on this setup? Ground Control style with adjustable sleeves?
yep.
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Old Feb 28, 2014 | 06:28 PM
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Originally Posted by j9fd3s
yep.
Thank you, how much spring can the AGX can handle? Do you think 400/275 is too much?
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Old Feb 28, 2014 | 08:38 PM
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From: https://www2.mazda.com/en/100th/
Originally Posted by Laxfreak3557
Thank you, how much spring can the AGX can handle? Do you think 400/275 is too much?
that's what i had in the 3 rotor, i liked it.
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