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coilover question

C

Classy Pontiac

New member
Alright I am planning on doing a coilover setup with my new agx struts. I am planning on using this car to autox and things like that. So what I was thinking was putting 500lb springs in the front and putting 400lb springs in the rear. Would this work or is it too strong? I would like it to be pretty stiff. Thanks in advance.
 


That is too much In my opinion.

What you will want to go for are springs that are rated for the valving of the struts. I have 400# front and 350# rear, my ride is pretty jarring (stiff doesn't always mean handling). I would imagine the sweet spot for AGX's are around 200-300 area, but I'm not 100% sure.

Matt has been all about Bilstein's mono tubes and having them valved specifically to a certain setup and I agree with him, its probably the best route. Since you already have the AGX's look into finding out what the sweet spot is spring rate wise.
 
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Google search reveals I was pretty damn close.

Review: Suspension- KYB AGX Shocks, Racing Beat Springs, Flyin'Miata Swaybars

Guy seems to think 200# - 250#. I'd run the later of the two in the rear, since a stiffened up rear will help this car rotate around corners; with that 200# up front, I'd stay away from the stiffest Front sway bar, just because these cars are nose heavy and will understeer like a pig; maybe stick to stock or one or two steps up; dialing in your setting on the AGX will be the other part of it. Once you go out a few times on street tires, you will find that limit, leaving you wanting more, so once you reach that point, you will want track tires and wheels and that will make all the difference in the world.
 
I have the KYB AGX, I'm only running what I am running because of the drop I'm on (around 3.5-4") You will want to find the magic spring rate and only drop 1.5" tops, the more you keep those LCA's parallel with the ground the better. That is why shortening your AGX's rod may not be a bad idea either, since your not after a big drop, then a shortened rod won't hurt you. Other things you can do are when you go for an alignment you want to zero out the toe (I think GPs run 0 toe out) or go 0.5* positive. Going much more then that you will just burn tires (at 0.5* you will burn tires a little faster than normal but its livable) and your turn in will be like night and day.

As far as ZZP spring rates, I think they run on the light side of things to keep the stock feel to the car, I think 175# and 250# (front/rear respectively). These springs are cheap on Summit, I think $20 a spring, so you may have to try one set of springs for a season, see how it feels and then change to another spring another season, you have to find what is best for you and your driving style. But I'd keep it between 200-300#'s.

Other things I have considered in the past were Sub Frame Connectors (google it), alot of guys go custom here. I'd tie the front subframe to the rear trailing if I could (I think that would be the best route, but not 100% sure if it would be feasible). These will help stop body flex from corner to corner, which this car has....BAD.

Other options are Fender braces as well, which when making a sharp turn in, will keep the front pointed straight and where you turn. Since when they make a frame for a car, the passenger cell tends to be seperate from the engine bay compartment, so the firewall can be a weak point. This car doesn't exhibit it as bad as some cars I've had in the past, but it does have some weakness. These two mods can be done down the line once you dial in your suspension and you want to nickel and dime everything.

Waiting for Matt to chime in....

There was also talk of aluminum inserts for the subframe bushings at one time, but not sure what happened to that.
 
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Drunkie said:
I have the KYB AGX, I'm only running what I am running because of the drop I'm on (around 3.5-4") You will want to find the magic spring rate and only drop 1.5" tops, the more you keep those LCA's parallel with the ground the better. That is why shortening your AGX's rod may not be a bad idea either, since your not after a big drop, then a shortened rod won't hurt you. Other things you can do are when you go for an alignment you want to zero out the toe (I think GPs run 0 toe out) or go 0.5* positive. Going much more then that you will just burn tires (at 0.5* you will burn tires a little faster than normal but its livable) and your turn in will be like night and day.
Click to expand...

Ran upwards of 3* of toe out. It made turn in much more lively.

Drunkie said:
As far as ZZP spring rates, I think they run on the light side of things to keep the stock feel to the car, I think 175# and 250# (front/rear respectively). These springs are cheap on Summit, I think $20 a spring, so you may have to try one set of springs for a season, see how it feels and then change to another spring another season, you have to find what is best for you and your driving style. But I'd keep it between 200-300#'s.
Click to expand...

ZZP is 350/275

Drunkie said:
Other things I have considered in the past were Sub Frame Connectors (google it), alot of guys go custom here. I'd tie the front subframe to the rear trailing if I could (I think that would be the best route, but not 100% sure if it would be feasible). These will help stop body flex from corner to corner, which this car has....BAD.
Click to expand...

The amount of effort involved in this might not be worth it. Just starting with a better platform would have better results.

If you're serious, you're going to want something like this:

13-69920.jpg


Flyin' Miata : Chassis : Stiffening : FM butterfly brace

Drunkie said:
Waiting for Matt to chime in....

There was also talk of aluminum inserts for the subframe bushings at one time, but not sure what happened to that.
Click to expand...

Was tempted to get into all of that, but I decided a new subframe and bushings wasn't worth the effort. Same story with the SFC's.

I found the rear was too weak and flexed under any high speed sweeping corners. Whether that was my stock lateral arm bushings or the rear subframe itself flexing, I couldn't tell you.

What would probably happen after poly rear link bushings would be the brackets would begin to flex as they're also stamped steel pieces with no bracing. Think of the stock trailing arms.

After considering all of this, getting out might be the best option.
 
Well, alot of people said that about my Maxima, but I stuck with it and pretty soon I was posting better times then Miata's. Really if you want to just have fun then any car will work. If you want to be serious, get a well setup car....*cough cough* Saab. Saab's were known for their chasis's to be so strong that roll cages were just for display purposes only.
 
More bracing ideas:

volvo_s60_v70_s80_lower_rear_brace__47545.1296768584.800.800.jpg


s60_front_lower_brace__94263.1281051165.800.800.jpg


s60_front_lower_brace2__49713.1281051164.800.800.jpg


Essentially find things to tie the subframes to.

Look into converting front LCAs to H body style, or replacing front bushing with spherical bushing. Perhaps ZZP's new LCAs might be worth the risk.

As I said previously, question the rear subframe as well.
 
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You would need to speak directly with people who have tried various forms of chassis bracing on a W body.

AFAIK, no one here has that.
 
Years ago someone tried making subframe connectors, weld on the pinch weld with bolt on connectors that go across so there was still access to drop the exhaust.

Didn't sell, or really get produced.
 


Ok im getting some braces made up in auto cad right now. And Drunkie, how would you compare your ride with and eibach ride? Stiffer, softer, what? Thanks for the help guys
 
Alright I am getting ready to order some coilover parts but need some things cleared up. I was looking at get these sleeves jegs.com

I measured the agx shock housing and I got around 2.01~ I think it will fit but I am not 100% sure, And I dont really feel like spending $340 on a HT coilover DIY kit. Help would be appreciated.

Thanks
 
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